Variable frequency heat pump units and their control methods, devices, storage media and program products

Abstract

This invention discloses a variable frequency heat pump unit and its control method, device, storage medium, and computer program product. The method includes: determining the high-pressure range of the compressor by controlling a high-pressure threshold and a high-pressure protection threshold based on the compressor's block diagram; after the variable frequency heat pump unit is powered on and the compressor starts, acquiring the compressor's current high-pressure and current frequency; and controlling the compressor's current frequency based on the current high-pressure and high-pressure range to adjust the compressor's current high-pressure to within the compressor's high-pressure range. This solution, by determining the high-pressure range by controlling the high-pressure threshold and high-pressure protection threshold based on the compressor's block diagram, and by controlling the compressor's current frequency through frequency limiting and frequency reduction, controls the compressor's high-pressure within a set reasonable pressure range, thereby improving the reliability and safety of the unit's operation.

Description

Technical Field

[0001] This invention belongs to the technical field of variable frequency heat pump units, specifically relating to a control method, device, variable frequency heat pump unit, storage medium, and computer program product for a variable frequency heat pump unit. Background Technology

[0002] With the development of the heat pump market, heat pumps have become fully variable frequency, and how to control the pressure range of variable frequency units and ensure the reliability of compressors has become an urgent problem to be solved.

[0003] In related solutions, the pressure range control of variable frequency heat pump units is generally achieved by limiting the frequency of the unit to maintain the high pressure level when a certain high pressure threshold is exceeded. However, the high pressure threshold in this method is relatively simple, which can easily cause the unit to frequently trigger high pressure protection, affecting the reliable operation of the unit.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The purpose of this invention is to provide a control method, device, unit, storage medium, and computer program product for a variable frequency heat pump unit. This addresses the problem that in related solutions, pressure range control of the variable frequency heat pump unit typically involves limiting the unit's frequency to maintain a high pressure level when a certain high-pressure threshold is exceeded. However, this often leads to frequent high-pressure protection activation, affecting the unit's reliable operation. The invention aims to improve the reliability and safety of the unit by implementing at least one of the following protection mechanisms: frequency limiting, normal-speed frequency reduction, overclocking, rapid frequency reduction, extremely rapid frequency reduction, high-speed frequency reduction, and high-pressure protection.

[0006] This invention provides a control method for a variable frequency heat pump unit, the variable frequency heat pump unit having a compressor; the control method for the variable frequency heat pump unit includes: acquiring a block diagram control high-pressure threshold of the compressor and acquiring a high-pressure protection threshold of the compressor; determining a high-pressure range of the compressor based on the block diagram control high-pressure threshold and the high-pressure protection threshold of the compressor; after the variable frequency heat pump unit is powered on and the compressor is turned on, acquiring the current high-pressure of the compressor and acquiring the current frequency of the compressor; and controlling the current frequency of the compressor based on the current high-pressure of the compressor and the high-pressure range of the compressor to adjust the current high-pressure of the compressor to within the high-pressure range of the compressor.

[0007] In some embodiments, determining the high-pressure range of the compressor based on the high-pressure control threshold of the compressor block diagram and the high-pressure protection threshold of the compressor includes: determining the difference between the high-pressure control threshold of the compressor block diagram and a preset first pressure threshold as the frequency-limiting high-pressure threshold of the compressor; determining the difference between the high-pressure control threshold of the compressor block diagram and a preset second pressure threshold as the first rate-reducing high-pressure threshold of the compressor; determining the sum of the high-pressure control threshold of the compressor block diagram and a preset third pressure threshold as the second rate-reducing high-pressure threshold of the compressor; and determining the high-pressure protection threshold of the compressor... The difference between the pressure threshold and the preset fourth pressure threshold is determined as the third-rate frequency reduction high-pressure threshold of the compressor; the difference between the high-pressure protection pressure threshold and the preset fifth pressure threshold of the compressor is determined as the fourth-rate frequency reduction high-pressure threshold of the compressor; the high-pressure range of the compressor is determined according to the frequency limiting high-pressure threshold of the compressor, the block diagram control high-pressure threshold of the compressor, the first-rate frequency reduction high-pressure threshold of the compressor, the second-rate frequency reduction high-pressure threshold of the compressor, the third-rate frequency reduction high-pressure threshold of the compressor, the fourth-rate frequency reduction high-pressure threshold of the compressor, and the high-pressure protection pressure threshold of the compressor.

[0008] In some embodiments, the high-pressure range of the compressor includes: a pressure interval divided by a frequency-limited high-pressure threshold, a block diagram controlled high-pressure threshold, a first-rate frequency-reducing high-pressure threshold, a second-rate frequency-reducing high-pressure threshold, a third-rate frequency-reducing high-pressure threshold, a fourth-rate frequency-reducing high-pressure threshold, and a high-pressure protection threshold, which are sequentially increased. Controlling the current frequency of the compressor based on its current high-pressure and the high-pressure range includes: determining whether the current high-pressure of the compressor is continuously detected to be greater than or equal to the frequency-limited high-pressure threshold and less than the first-rate frequency-reducing high-pressure threshold within a first set time period under a preset frequency-limiting mode; if it is determined that the current high-pressure of the compressor is continuously detected to be greater than or equal to the frequency-limited high-pressure threshold and less than the first-rate frequency-reducing high-pressure threshold within a first set time period under a preset frequency-limiting mode... If the compressor's first rate reduction high-pressure threshold is reached, the compressor is controlled to enter a preset frequency limiting mode to restrict the rise of the compressor's current frequency. Then, it is determined whether the compressor's current high-pressure is continuously detected to be lower than the compressor's frequency limiting high-pressure threshold within a second set time period under the preset frequency limiting mode. If it is determined that the compressor's current high-pressure is continuously detected to be lower than the compressor's frequency limiting high-pressure threshold within the second set time period under the preset frequency limiting mode, the compressor's current frequency is maintained for a third set time under the preset frequency limiting mode before exiting the preset frequency limiting mode to remove the restriction on the rise of the compressor's current frequency and resume the control of the compressor's current frequency rise and fall. If it is determined that the compressor's current high-pressure is not continuously detected to be lower than the compressor's frequency limiting high-pressure threshold within the second set time period under the preset frequency limiting mode, the process returns to the previous state to re-control the compressor's current frequency based on the compressor's current high-pressure and the compressor's high-pressure range.

[0009] In some embodiments, the high-pressure range of the compressor includes: a pressure interval divided by a series of increasing high-pressure thresholds: a frequency-limiting high-pressure threshold, a block diagram-controlled high-pressure threshold, a first-rate frequency-reduction high-pressure threshold, a second-rate frequency-reduction high-pressure threshold, a third-rate frequency-reduction high-pressure threshold, a fourth-rate frequency-reduction high-pressure threshold, and a high-pressure protection pressure threshold. Controlling the current frequency of the compressor based on its current high-pressure and the high-pressure range further includes determining whether to continuously reduce the frequency at a preset first rate. If, within a first set time period in the preset first-rate frequency reduction mode, the current high-pressure of the compressor is detected to be greater than or equal to the first-rate frequency reduction high-pressure threshold of the compressor, and less than the block diagram control high-pressure threshold of the compressor; if it is determined that the current high-pressure of the compressor is continuously greater than or equal to the first-rate frequency reduction high-pressure threshold of the compressor, and less than the block diagram control high-pressure threshold of the compressor within the first set time period in the preset first-rate frequency reduction mode, then the compressor is controlled to enter the preset first-rate frequency reduction mode to control the current frequency of the compressor to decrease by the preset first-rate frequency reduction value; then, it is re-determined whether the compressor is continuously in the preset first-rate frequency reduction mode within the first set time period. If, within a certain time period, the current high-pressure of the compressor is detected to be greater than or equal to the first rate frequency reduction high-pressure threshold of the compressor, and less than the block diagram control high-pressure threshold of the compressor, then if so, the current frequency of the compressor is controlled to decrease by a preset first rate frequency reduction value at preset first rate frequency reduction intervals; otherwise, the process returns to re-controlling the current frequency of the compressor based on the current high-pressure of the compressor and the high-pressure range of the compressor; after controlling the current frequency of the compressor to decrease by the preset first rate frequency reduction value at preset first rate frequency reduction intervals, it is determined whether the current frequency is continuously detected within a second set time period under the preset first rate frequency reduction mode. The current high pressure of the compressor is less than the first rate reduction high pressure threshold of the compressor; if it is determined that the current high pressure of the compressor is less than the first rate reduction high pressure threshold of the compressor is continuously detected within a second set time in the preset first rate reduction mode, then after maintaining the current frequency of the compressor in the preset first rate reduction mode for a third set time, the compressor is controlled to exit the preset first rate reduction mode, so as to exit the control of the current frequency reduction of the compressor according to the preset first rate reduction mode, and then the current frequency of the compressor is controlled again according to the current high pressure of the compressor and the high pressure range of the compressor;If it is determined that the current high-pressure of the compressor is not continuously lower than the high-pressure threshold of the compressor's first-rate frequency reduction mode within a second set time period, then the process returns to re-control the compressor's current frequency based on the compressor's current high-pressure and the compressor's high-pressure range.

[0010] In some embodiments, the high-pressure range of the compressor includes: a pressure interval divided by a series of increasing high-pressure thresholds: a frequency-limiting high-pressure threshold, a block diagram-controlled high-pressure threshold, a first-rate frequency-reducing high-pressure threshold, a second-rate frequency-reducing high-pressure threshold, a third-rate frequency-reducing high-pressure threshold, a fourth-rate frequency-reducing high-pressure threshold, and a high-pressure protection pressure threshold. Controlling the current frequency of the compressor based on its current high-pressure and the high-pressure range further includes determining whether it is continuously within a preset range. If, within a first set time period under the block diagram control mode, the current high-pressure of the compressor is detected to be greater than or equal to the block diagram control high-pressure threshold and less than the second rate-reduction high-pressure threshold, then if it is determined that the current high-pressure of the compressor is continuously greater than or equal to the block diagram control high-pressure threshold and less than the second rate-reduction high-pressure threshold within the first set time period under the preset block diagram control mode, the compressor is controlled to enter the preset block diagram control mode to control the current frequency of the compressor to decrease by the preset block diagram control reduction value; then, it is re-determined whether the compressor is continuously in the preset block diagram control mode. Within a first set time period, if the current high-pressure of the compressor is detected to be greater than or equal to the high-pressure threshold of the compressor's block diagram control and less than the high-pressure threshold of the compressor's second rate reduction high-frequency control: if so, the current frequency of the compressor is controlled to decrease by a preset block diagram control reduction value every preset block diagram control time; otherwise, the process returns to re-controlling the current frequency of the compressor based on the current high-pressure of the compressor and the high-pressure range of the compressor; after controlling the current frequency of the compressor to decrease by the preset block diagram control reduction value every preset block diagram control time, it is determined whether the second set of the preset block diagram control mode is continuously in progress. If the current high pressure of the compressor is detected to be less than the high pressure threshold of the compressor's block diagram control within a certain time period; if it is determined that the current high pressure of the compressor is detected to be less than the high pressure threshold of the compressor's block diagram control within a second set time period under the preset block diagram control mode, then after maintaining the current frequency of the compressor under the preset block diagram control mode for a third set time, the compressor is controlled to exit the preset block diagram control mode, so as to exit the frequency reduction of the compressor controlled by the preset block diagram control mode. Then, the current frequency of the compressor is controlled again according to the current high pressure of the compressor and the high pressure range of the compressor.If it is determined that the current high-pressure of the compressor is not continuously lower than the high-pressure threshold of the compressor within the second set time of the preset block diagram control mode, and it is also determined that the current high-pressure of the compressor is not continuously lower than the high-pressure threshold of the compressor within the continuous control time of the preset block diagram control mode, then the compressor is controlled to stop, and the variable frequency heat pump unit is controlled to stop.

[0011] In some embodiments, the high-pressure range of the compressor includes: a pressure interval divided by a series of increasing high-pressure thresholds: a frequency-limiting high-pressure threshold, a block diagram-controlled high-pressure threshold, a first-rate frequency-reduction high-pressure threshold, a second-rate frequency-reduction high-pressure threshold, a third-rate frequency-reduction high-pressure threshold, a fourth-rate frequency-reduction high-pressure threshold, and a high-pressure protection pressure threshold; wherein controlling the current frequency of the compressor based on its current high-pressure and the high-pressure range further includes: determining whether to continuously reduce the frequency at a preset second rate. If, within a first set time period in the preset second-rate frequency reduction mode, the current high-pressure of the compressor is detected to be greater than or equal to the second-rate frequency reduction high-pressure threshold and less than the third-rate frequency reduction high-pressure threshold, then the compressor is controlled to enter the preset second-rate frequency reduction mode to control the current frequency of the compressor to decrease by the preset second-rate frequency reduction value. Afterwards, it is re-determined whether the current high-pressure of the compressor is continuously greater than or equal to the second-rate frequency reduction high-pressure threshold and less than the third-rate frequency reduction high-pressure threshold within the first set time period in the preset second-rate frequency reduction mode. If, within a set time period, the current high-pressure of the compressor is detected to be greater than or equal to the second-rate frequency reduction high-pressure threshold and less than the third-rate frequency reduction high-pressure threshold, then if so, the current frequency of the compressor is controlled to decrease by a preset second-rate frequency reduction value at preset second-rate frequency reduction intervals; otherwise, the process returns to re-controlling the current frequency of the compressor based on its current high-pressure and high-pressure range. After controlling the current frequency of the compressor to decrease by the preset second-rate frequency reduction value at preset second-rate frequency reduction intervals, it is determined whether the compressor is continuously detected within a second set time period under the preset second-rate frequency reduction mode. If the current high pressure of the compressor is detected to be less than the second-rate frequency reduction high pressure threshold of the compressor; if it is determined that the current high pressure of the compressor is continuously detected to be less than the second-rate frequency reduction high pressure threshold of the compressor within a second set time in the preset second-rate frequency reduction mode, then after maintaining the current frequency of the compressor in the preset second-rate frequency reduction mode for a third set time, the compressor is controlled to exit the preset second-rate frequency reduction mode, so as to exit the control of the current frequency reduction of the compressor according to the preset second-rate frequency reduction mode. Then, the current frequency of the compressor is controlled again according to the current high pressure of the compressor and the high pressure range of the compressor.If it is determined that the current high pressure of the compressor is not lower than the high pressure threshold of the compressor at the second rate reduction mode within a second set time period without continuous detection, and it is determined that the current high pressure of the compressor is not lower than the high pressure threshold of the compressor at the second rate reduction mode within a continuous control time period without continuous detection, then the compressor is controlled to stop, and the variable frequency heat pump unit is controlled to stop.

[0012] And / or, based on the current high pressure of the compressor and the high pressure range of the compressor, controlling the current frequency of the compressor further includes: determining whether the current high pressure of the compressor is continuously detected to be greater than or equal to the high pressure threshold of the compressor's third rate frequency reduction mode and less than the high pressure threshold of the compressor's fourth rate frequency reduction mode within a first set time period; if it is determined that the current high pressure of the compressor is continuously detected to be greater than or equal to the high pressure threshold of the compressor's third rate frequency reduction mode and less than the high pressure threshold of the compressor's fourth rate frequency reduction mode within a first set time period; If the compressor is controlled to enter a preset third-rate frequency reduction mode, the current frequency of the compressor will be reduced by a preset third-rate frequency reduction value. Then, it will be re-determined whether the current high-pressure of the compressor is detected to be greater than or equal to the third-rate frequency reduction high-pressure threshold and less than the fourth-rate frequency reduction high-pressure threshold within a first set time period in the preset third-rate frequency reduction mode. If so, the current frequency of the compressor will be controlled to decrease by a preset third-rate frequency reduction value every preset third-rate frequency reduction time. Otherwise, the process will return to re-adjust the current frequency of the compressor based on its current high-pressure and the compressor's high-pressure range. Frequency is controlled; after controlling the current frequency of the compressor to decrease by a preset third rate reduction value at preset third rate reduction times, it is determined whether the current high pressure of the compressor is continuously detected to be less than the high pressure threshold of the compressor's third rate reduction mode within a third set time period in the preset third rate reduction mode; if it is determined that the current high pressure of the compressor is continuously detected to be less than the high pressure threshold of the compressor's third rate reduction mode within a third set time period in the preset third rate reduction mode, then after maintaining the current frequency of the compressor in the preset third rate reduction mode for a fourth time period, the compressor is controlled to exit the preset third rate reduction mode, so as to... Exit the preset third-rate frequency reduction mode to control the compressor's current frequency reduction, and then re-control the compressor's current frequency based on the compressor's current high pressure and the compressor's high pressure range; if it is determined that the compressor's current high pressure is not continuously detected to be less than the compressor's third-rate frequency reduction high pressure threshold within the third set time of the preset third-rate frequency reduction mode, and it is determined that the compressor's current high pressure is not continuously detected to be less than the compressor's third-rate frequency reduction high pressure threshold within the continuous control time of the preset third-rate frequency reduction mode, then control the compressor to stop, and control the variable frequency heat pump unit to stop;

[0013] And / or, based on the current high pressure of the compressor and the high pressure range of the compressor, controlling the current frequency of the compressor further includes: determining whether the current high pressure of the compressor is continuously detected to be greater than or equal to the high pressure threshold of the compressor's fourth-rate frequency reduction mode and less than the high pressure protection high pressure threshold of the compressor within a first set time period under the preset fourth-rate frequency reduction mode; if it is determined that the current high pressure of the compressor is continuously detected to be greater than or equal to the high pressure threshold of the compressor's fourth-rate frequency reduction mode and less than the high pressure protection high pressure threshold of the compressor within a first set time period under the preset fourth-rate frequency reduction mode, The compressor is then controlled to enter a preset fourth-rate frequency reduction mode to reduce its current frequency by a preset fourth-rate frequency reduction value. Then, it is re-determined whether, within a first set time period under the preset fourth-rate frequency reduction mode, the compressor's current high-pressure is detected to be greater than or equal to the compressor's fourth-rate frequency reduction high-pressure threshold and less than the compressor's high-pressure protection high-pressure threshold. If so, the compressor's current frequency is controlled to decrease by the preset fourth-rate frequency reduction value every preset fourth-rate frequency reduction time interval. Otherwise, the process returns to re-evaluating the compressor's current frequency based on its current high-pressure and high-pressure range. Frequency is controlled; after controlling the current frequency of the compressor to decrease by a preset fourth rate reduction value at preset fourth rate reduction times, it is determined whether the current high pressure of the compressor is continuously detected to be less than the high pressure threshold of the compressor's fourth rate reduction mode within the fourth time period of the preset fourth rate reduction mode; if it is determined that the current high pressure of the compressor is continuously detected to be less than the high pressure threshold of the compressor's fourth rate reduction mode within the fourth time period of the preset fourth rate reduction mode, then after maintaining the current frequency of the compressor in the preset fourth rate reduction mode for the fourth time period, the compressor is controlled to exit the preset fourth rate reduction mode to exit... The compressor's current frequency is reduced according to a preset fourth-rate frequency reduction mode. Then, the compressor's current frequency is controlled again based on the compressor's current high-pressure and the compressor's high-pressure range. If it is determined that the compressor's current high-pressure is not continuously lower than the compressor's fourth-rate frequency reduction high-pressure threshold within the fourth time period of the preset fourth-rate frequency reduction mode, and it is determined that the compressor's current high-pressure is not continuously lower than the compressor's fourth-rate frequency reduction high-pressure threshold within the continuous control time of the preset fourth-rate frequency reduction mode, then the compressor is controlled to stop, and the variable frequency heat pump unit is controlled to stop.

[0014] And / or, based on the current high pressure of the compressor and the high pressure range of the compressor, controlling the current frequency of the compressor further includes: determining whether the current high pressure of the compressor is continuously detected to be greater than or equal to the high pressure protection high pressure threshold of the compressor within a first set time in a preset high pressure protection mode; if it is determined that the current high pressure of the compressor is continuously detected to be greater than or equal to the high pressure protection high pressure threshold of the compressor within a first set time in a preset high pressure protection mode, then controlling the high pressure switch of the variable frequency heat pump unit to open and controlling the variable frequency heat pump unit to stop.

[0015] In conjunction with the above method, another aspect of the present invention provides a control device for a variable frequency heat pump unit, the variable frequency heat pump unit having a compressor; the control device for the variable frequency heat pump unit includes: an acquisition unit configured to acquire a block diagram control high-pressure threshold of the compressor and acquire a high-pressure protection pressure threshold of the compressor; a control unit configured to determine a high-pressure range of the compressor based on the block diagram control high-pressure threshold of the compressor and the high-pressure protection pressure threshold of the compressor; the acquisition unit is further configured to acquire the current high-pressure of the compressor and the current frequency of the compressor after the variable frequency heat pump unit is powered on and after the compressor is turned on; the control unit is further configured to control the current frequency of the compressor based on the current high-pressure of the compressor and the high-pressure range of the compressor, so as to adjust the current high-pressure of the compressor to the high-pressure range of the compressor.

[0016] In some embodiments, the control unit determines the high-pressure range of the compressor based on the high-pressure threshold controlled by the compressor's block diagram and the high-pressure protection threshold of the compressor, including: determining the difference between the high-pressure threshold controlled by the compressor's block diagram and a preset first pressure threshold as the compressor's frequency-limiting high-pressure threshold; determining the difference between the high-pressure threshold controlled by the compressor's block diagram and a preset second pressure threshold as the compressor's first rate-reducing high-pressure threshold; determining the sum of the high-pressure threshold controlled by the compressor's block diagram and a preset third pressure threshold as the compressor's second rate-reducing high-pressure threshold; and determining the high-pressure range of the compressor's high-pressure range... The difference between the pressure protection threshold and the preset fourth pressure threshold is determined as the third-rate frequency reduction high-pressure threshold of the compressor; the difference between the high-pressure protection threshold and the preset fifth pressure threshold of the compressor is determined as the fourth-rate frequency reduction high-pressure threshold of the compressor; the high-pressure range of the compressor is determined based on the compressor's frequency limiting high-pressure threshold, the compressor's block diagram control high-pressure threshold, the compressor's first-rate frequency reduction high-pressure threshold, the compressor's second-rate frequency reduction high-pressure threshold, the compressor's third-rate frequency reduction high-pressure threshold, the compressor's fourth-rate frequency reduction high-pressure threshold, and the compressor's high-pressure protection threshold.

[0017] In some embodiments, the high-pressure range of the compressor includes: a pressure interval divided by a frequency-limiting high-pressure threshold, a block diagram-controlled high-pressure threshold, a first-rate frequency-reducing high-pressure threshold, a second-rate frequency-reducing high-pressure threshold, a third-rate frequency-reducing high-pressure threshold, a fourth-rate frequency-reducing high-pressure threshold, and a high-pressure protection pressure threshold, which are sequentially increased by the compressor; the control unit controls the current frequency of the compressor based on the current high-pressure of the compressor and the high-pressure range of the compressor, including: determining whether the current high-pressure of the compressor is continuously detected to be greater than or equal to the frequency-limiting high-pressure threshold and less than the first-rate frequency-reducing high-pressure threshold within a first set time in a preset frequency-limiting mode; if it is determined that the current high-pressure of the compressor is continuously detected to be greater than or equal to the frequency-limiting high-pressure threshold and less than the first-rate frequency-reducing high-pressure threshold within a first set time in a preset frequency-limiting mode, and If the current high pressure is less than the first rate-reduction high-pressure threshold of the compressor, the compressor is controlled to enter a preset frequency-limiting mode to limit the rise of the compressor's current frequency. Then, it is determined whether the current high pressure of the compressor is continuously less than the frequency-limiting high-pressure threshold within a second set time period under the preset frequency-limiting mode. If it is determined that the current high pressure of the compressor is continuously less than the frequency-limiting high-pressure threshold within the second set time period under the preset frequency-limiting mode, the compressor's current frequency is maintained for a third set time under the preset frequency-limiting mode, and then the compressor is controlled to exit the preset frequency-limiting mode to remove the restriction on the rise of the compressor's current frequency and resume the control of the rise and fall of the compressor's current frequency. If it is determined that the current high pressure of the compressor is not continuously less than the frequency-limiting high-pressure threshold within the second set time period under the preset frequency-limiting mode, the process returns to the previous state to re-control the compressor's current frequency based on the current high pressure and the compressor's high-pressure range.

[0018] In some embodiments, the high-pressure range of the compressor includes: a pressure interval divided by a series of increasing pressure ranges: a frequency-limited high-pressure threshold of the compressor, a block diagram controlled high-pressure threshold of the compressor, a first-rate frequency-reducing high-pressure threshold of the compressor, a second-rate frequency-reducing high-pressure threshold of the compressor, a third-rate frequency-reducing high-pressure threshold of the compressor, a fourth-rate frequency-reducing high-pressure threshold of the compressor, and a high-pressure protection pressure threshold of the compressor; the control unit controls the current frequency of the compressor based on the current high-pressure of the compressor and the high-pressure range of the compressor, and further includes: determining whether the frequency is continuously within a preset range. If, within a first set time period under a first-rate frequency reduction mode, the current high-pressure of the compressor is detected to be greater than or equal to the first-rate frequency reduction high-pressure pressure threshold of the compressor, and less than the block diagram control high-pressure pressure threshold of the compressor; if it is determined that the current high-pressure of the compressor is continuously greater than or equal to the first-rate frequency reduction high-pressure threshold of the compressor, and less than the block diagram control high-pressure pressure threshold of the compressor within the first set time period under the preset first-rate frequency reduction mode, then the compressor is controlled to enter the preset first-rate frequency reduction mode to control the current frequency of the compressor to decrease by the preset first-rate frequency reduction value; then, it is re-determined whether the compressor is continuously in the preset first-rate frequency reduction mode. If, within a first set time period, the current high-pressure of the compressor is detected to be greater than or equal to the compressor's first rate-reduction high-pressure pressure threshold and less than the compressor's block diagram control high-pressure pressure threshold, then if so, the compressor's current frequency is controlled to decrease by a preset first rate reduction value at preset first rate reduction intervals; otherwise, the process returns to re-controlling the compressor's current frequency based on the compressor's current high-pressure and the compressor's high-pressure range. After controlling the compressor's current frequency to decrease by the preset first rate reduction value at preset first rate reduction intervals, it is determined whether the compressor is continuously detected within a second set time period under the preset first rate reduction mode. If the current high pressure of the compressor is detected to be less than the first rate reduction high pressure threshold of the compressor; if it is determined that the current high pressure of the compressor is detected to be less than the first rate reduction high pressure threshold of the compressor continuously within a second set time in the preset first rate reduction mode, then after maintaining the current frequency of the compressor in the preset first rate reduction mode for a third set time, the compressor is controlled to exit the preset first rate reduction mode, so as to exit the control of the current frequency reduction of the compressor according to the preset first rate reduction mode. Then, the current frequency of the compressor is controlled again according to the current high pressure of the compressor and the high pressure range of the compressor.If it is determined that the current high-pressure of the compressor is not continuously lower than the high-pressure threshold of the compressor's first-rate frequency reduction mode within a second set time period, then the process returns to re-control the compressor's current frequency based on the compressor's current high-pressure and the compressor's high-pressure range.

[0019] In some embodiments, the high-pressure range of the compressor includes: a pressure interval divided by a series of increasing pressure ranges: a frequency-limited high-pressure threshold of the compressor, a block diagram controlled high-pressure threshold of the compressor, a first-rate frequency-reducing high-pressure threshold of the compressor, a second-rate frequency-reducing high-pressure threshold of the compressor, a third-rate frequency-reducing high-pressure threshold of the compressor, a fourth-rate frequency-reducing high-pressure threshold of the compressor, and a high-pressure protection pressure threshold of the compressor; the control unit controls the current frequency of the compressor based on the current high-pressure of the compressor and the high-pressure range of the compressor, and further includes: determining whether to connect... If, within a first set time period under a preset block diagram control mode, the current high-pressure of the compressor is detected to be greater than or equal to the high-pressure threshold of the compressor's block diagram control and less than the high-pressure threshold of the compressor's second rate-reduction high-pressure; and if it is determined that the current high-pressure of the compressor is continuously greater than or equal to the high-pressure threshold of the compressor's block diagram control and less than the high-pressure threshold of the compressor's second rate-reduction high-pressure, then the compressor is controlled to enter a preset block diagram control mode to control the compressor's current frequency to decrease by a preset block diagram control reduction value; then, it is re-determined whether the current high-pressure of the compressor is continuously greater than or equal to the high-pressure threshold of the compressor's block diagram control and less than the high-pressure threshold of the compressor's second rate-reduction high-pressure; In the first set time period of the control mode, if the current high pressure of the compressor is detected to be greater than or equal to the high pressure threshold of the compressor's block diagram control and less than the high pressure threshold of the compressor's second rate frequency reduction, then if so, the current frequency of the compressor is controlled to decrease by a preset block diagram control frequency reduction value every preset block diagram control time; otherwise, the process returns to re-controlling the current frequency of the compressor based on the current high pressure of the compressor and the high pressure range of the compressor. After controlling the current frequency of the compressor to decrease by the preset block diagram control frequency reduction value every preset block diagram control time, it is determined whether the second set time of the preset block diagram control mode is continuously maintained. If the current high pressure of the compressor is detected to be less than the high pressure threshold of the compressor's block diagram control within a certain time period, and if it is determined that the current high pressure of the compressor is detected to be less than the high pressure threshold of the compressor's block diagram control within a second set time period under the preset block diagram control mode, then after maintaining the current frequency of the compressor under the preset block diagram control mode for a third set time, the compressor is controlled to exit the preset block diagram control mode to exit the frequency reduction control of the compressor under the preset block diagram control mode, and then the current frequency of the compressor is controlled again according to the current high pressure of the compressor and the high pressure range of the compressor.If it is determined that the current high-pressure of the compressor is not continuously lower than the high-pressure threshold of the compressor within the second set time of the preset block diagram control mode, and it is also determined that the current high-pressure of the compressor is not continuously lower than the high-pressure threshold of the compressor within the continuous control time of the preset block diagram control mode, then the compressor is controlled to stop, and the variable frequency heat pump unit is controlled to stop.

[0020] In some embodiments, the high-pressure range of the compressor includes: a pressure interval divided by a series of increasing pressure ranges: a frequency-limiting high-pressure threshold of the compressor, a block diagram-controlled high-pressure threshold of the compressor, a first-rate frequency-reducing high-pressure threshold of the compressor, a second-rate frequency-reducing high-pressure threshold of the compressor, a third-rate frequency-reducing high-pressure threshold of the compressor, a fourth-rate frequency-reducing high-pressure threshold of the compressor, and a high-pressure protection pressure threshold of the compressor; wherein, the control unit, based on the current high-pressure of the compressor and the high-pressure range of the compressor, controls the current frequency of the compressor, and further includes: determining whether it is continuously within a preset range. If, within a first set time period under the second-rate frequency reduction mode, the current high-pressure of the compressor is detected to be greater than or equal to the second-rate frequency reduction high-pressure pressure threshold and less than the third-rate frequency reduction high-pressure pressure threshold, then the compressor is controlled to enter the preset second-rate frequency reduction mode to control the current frequency of the compressor to decrease by the preset second-rate frequency reduction value; then, it is re-determined whether the current high-pressure of the compressor is continuously greater than or equal to the second-rate frequency reduction high-pressure threshold and less than the third-rate frequency reduction high-pressure threshold within the first set time period under the preset second-rate frequency reduction mode. If, within a first set time period, the current high-pressure of the compressor is detected to be greater than or equal to the second-rate frequency reduction high-pressure threshold and less than the third-rate frequency reduction high-pressure threshold, then the current frequency of the compressor is controlled to decrease by a preset second-rate frequency reduction value at preset second-rate frequency reduction intervals; otherwise, the process returns to re-controlling the current frequency of the compressor based on the current high-pressure and high-pressure range of the compressor. After controlling the current frequency of the compressor to decrease by the preset second-rate frequency reduction value at preset second-rate frequency reduction intervals, it is determined whether the second set time is continuously within the preset second-rate frequency reduction mode. If the compressor's current high pressure is detected to be less than the compressor's second-rate frequency reduction high pressure threshold, and if it is determined that the compressor's current high pressure is continuously less than the compressor's second-rate frequency reduction high pressure threshold within a second set time in the preset second-rate frequency reduction mode, then after maintaining the compressor's current frequency in the preset second-rate frequency reduction mode for a third set time, the compressor is controlled to exit the preset second-rate frequency reduction mode, so as to exit the control of the compressor's current frequency reduction according to the preset second-rate frequency reduction mode. Then, the compressor's current frequency is controlled again according to the compressor's current high pressure and the compressor's high pressure range.If it is determined that the current high pressure of the compressor is not lower than the high pressure threshold of the compressor at the second rate reduction mode within a second set time period without continuous detection, and it is determined that the current high pressure of the compressor is not lower than the high pressure threshold of the compressor at the second rate reduction mode within a continuous control time period without continuous detection, then the compressor is controlled to stop, and the variable frequency heat pump unit is controlled to stop.

[0021] And / or, the control unit, based on the current high pressure of the compressor and the high pressure range of the compressor, controls the current frequency of the compressor, further comprising: determining whether, within a first set time period under a preset third-rate frequency reduction mode, the current high pressure of the compressor is detected to be greater than or equal to the third-rate frequency reduction high pressure threshold of the compressor and less than the fourth-rate frequency reduction high pressure threshold of the compressor; if it is determined that, within a first set time period under the preset third-rate frequency reduction mode, the current high pressure of the compressor is greater than or equal to the third-rate frequency reduction high pressure threshold of the compressor and less than the fourth-rate frequency reduction high pressure threshold of the compressor; If the pressure threshold is reached, the compressor is controlled to enter a preset third-rate frequency reduction mode to control the compressor's current frequency to decrease by a preset third-rate frequency reduction value. Then, it is re-determined whether the compressor's current high-pressure is continuously detected to be greater than or equal to the compressor's third-rate frequency reduction high-pressure threshold and less than the compressor's fourth-rate frequency reduction high-pressure threshold within a first set time period in the preset third-rate frequency reduction mode. If so, the compressor's current frequency is controlled to decrease by a preset third-rate frequency reduction value every preset third-rate frequency reduction time interval; otherwise, the process returns to re-adjusting the compressor based on its current high-pressure and the compressor's high-pressure range. The compressor's current frequency is controlled; after controlling the compressor's current frequency to decrease by a preset third rate reduction value at preset third rate reduction times, it is determined whether the compressor's current high pressure is continuously detected to be less than the compressor's third rate reduction high pressure threshold within a third set time period in the preset third rate reduction mode; if it is determined that the compressor's current high pressure is continuously detected to be less than the compressor's third rate reduction high pressure threshold within a third set time period in the preset third rate reduction mode, then after maintaining the compressor's current frequency in the preset third rate reduction mode for a fourth time period, the compressor is controlled to exit the preset third rate reduction mode. The compressor is deactivated by exiting the preset third-rate frequency reduction mode and controlling the current frequency of the compressor. Then, the current frequency of the compressor is controlled again according to the current high pressure of the compressor and the high pressure range of the compressor. If it is determined that the current high pressure of the compressor is not continuously detected to be less than the high pressure threshold of the compressor at the third rate frequency reduction mode within a third set time, and it is determined that the current high pressure of the compressor is not continuously detected to be less than the high pressure threshold of the compressor at the third rate frequency reduction mode within a continuous control time, then the compressor is controlled to stop and the variable frequency heat pump unit is controlled to stop.

[0022] And / or, the control unit, based on the current high pressure of the compressor and the high pressure range of the compressor, controls the current frequency of the compressor, further comprising: determining whether the current high pressure of the compressor is continuously detected to be greater than or equal to the high pressure threshold of the compressor's fourth-rate frequency reduction mode and less than the high pressure protection high pressure threshold of the compressor within a first set time period under the preset fourth-rate frequency reduction mode; if it is determined that the current high pressure of the compressor is continuously detected to be greater than or equal to the high pressure threshold of the compressor's fourth-rate frequency reduction mode and less than the high pressure protection high pressure threshold of the compressor within the first set time period under the preset fourth-rate frequency reduction mode, then... If the pressure threshold is reached, the compressor is controlled to enter a preset fourth-rate frequency reduction mode to control the compressor's current frequency to decrease by a preset fourth-rate frequency reduction value. Then, it is re-determined whether the compressor's current high-pressure is detected to be greater than or equal to the compressor's fourth-rate frequency reduction high-pressure threshold and less than the compressor's high-pressure protection high-pressure threshold within a first set time period under the preset fourth-rate frequency reduction mode. If yes, the compressor's current frequency is controlled to decrease by the preset fourth-rate frequency reduction value every preset fourth-rate frequency reduction time interval; otherwise, the process returns to re-adjusting the compressor based on its current high-pressure and high-pressure range. The compressor's current frequency is controlled; after controlling the compressor's current frequency to decrease by a preset fourth rate reduction value at preset fourth rate reduction intervals, it is determined whether the compressor's current high-pressure is continuously detected to be less than the compressor's fourth rate reduction high-pressure threshold within a fourth time interval of the preset fourth rate reduction mode; if it is determined that the compressor's current high-pressure is continuously detected to be less than the compressor's fourth rate reduction high-pressure threshold within a fourth time interval of the preset fourth rate reduction mode, then after maintaining the compressor's current frequency in the preset fourth rate reduction mode for a fourth time interval, the compressor is controlled to exit the preset fourth rate reduction mode. The compressor's current frequency is reduced by exiting the preset fourth-rate frequency reduction mode. Then, the compressor's current frequency is controlled again based on the compressor's current high pressure and the compressor's high pressure range. If it is determined that the compressor's current high pressure is not continuously lower than the compressor's fourth-rate frequency reduction high pressure threshold within the fourth time period of the preset fourth-rate frequency reduction mode, and it is determined that the compressor's current high pressure is not continuously lower than the compressor's fourth-rate frequency reduction high pressure threshold within the continuous control time of the preset fourth-rate frequency reduction mode, then the compressor is controlled to stop, and the variable frequency heat pump unit is controlled to stop.

[0023] And / or, the control unit, based on the current high pressure of the compressor and the high pressure range of the compressor, controls the current frequency of the compressor, further comprising: determining whether the current high pressure of the compressor is continuously detected to be greater than or equal to the high pressure protection high pressure threshold of the compressor within a first set time in a preset high pressure protection mode; if it is determined that the current high pressure of the compressor is continuously detected to be greater than or equal to the high pressure protection high pressure threshold of the compressor within the first set time in the preset high pressure protection mode, then controlling the high pressure switch of the variable frequency heat pump unit to open, and controlling the variable frequency heat pump unit to stop.

[0024] In conjunction with the above-mentioned device, the present invention further provides a variable frequency heat pump unit, including: the control device for the variable frequency heat pump unit described above.

[0025] In conjunction with the above method, the present invention further provides a storage medium comprising a stored program, wherein, when the program is executed, the device containing the storage medium is controlled to perform the steps of the control method for the variable frequency heat pump unit described above.

[0026] In conjunction with the above method, the present invention further provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the control method for the variable frequency heat pump unit described above.

[0027] Therefore, the solution of this invention, for the variable frequency heat pump unit, pre-sets pressure ranges corresponding to seven levels of pressure control: frequency limiting, normal speed frequency reduction, super compressor block diagram, rapid frequency reduction, rapid frequency reduction, super-rapid frequency reduction, and high-pressure protection. Different compressor frequency reduction amplitudes and dwell times are set for each pressure range. After the compressor of the variable frequency heat pump unit is started, the high-pressure pressure of the compressor is acquired. Based on the pressure range to which the high-pressure pressure belongs, at least one of the following protections is applied to the compressor: frequency limiting, normal speed frequency reduction, super compressor block diagram, rapid frequency reduction, super-rapid frequency reduction, super-rapid frequency reduction, and high-pressure protection, to control the high-pressure pressure of the compressor within a set reasonable pressure range. Thus, by applying at least one of these protections to the compressor, the high-pressure pressure of the compressor is controlled within a set reasonable pressure range, improving the reliability and safety of the unit's operation.

[0028] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0029] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0030] Figure 1 This is a flowchart illustrating an embodiment of the control method for a variable frequency heat pump unit according to the present invention;

[0031] Figure 2 This is a schematic flowchart of an embodiment of the method of the present invention for determining the high pressure range of the compressor;

[0032] Figure 3 This is a schematic flowchart of an embodiment of pressure control under a preset frequency limiting mode (such as a high-voltage frequency limiting mode) in the method of the present invention;

[0033] Figure 4 This is a schematic flowchart of an embodiment of pressure control in the method of the present invention under a preset first rate frequency reduction mode (such as a constant speed frequency limiting mode);

[0034] Figure 5 This is a schematic flowchart of an embodiment of pressure control in a preset block diagram control mode (such as a compressor block diagram control mode) in the method of the present invention;

[0035] Figure 6 This is a schematic flowchart of an embodiment of pressure control in a preset second rate reduction mode (such as a fast reduction mode) in the method of the present invention;

[0036] Figure 7 This is a schematic flowchart of an embodiment of pressure control in the method of the present invention under a preset third rate reduction mode (such as a rapid reduction mode);

[0037] Figure 8 This is a schematic flowchart of an embodiment of pressure control in the method of the present invention under a preset fourth rate reduction mode (such as a rapid reduction mode);

[0038] Figure 9 This is a schematic flowchart of an embodiment of pressure control in a preset high-pressure protection mode in the method of the present invention;

[0039] Figure 10 This is a schematic diagram of the structure of an embodiment of the control device for the variable frequency heat pump unit of the present invention;

[0040] Figure 11 Schematic diagram of compressor frequency limiting pressure;

[0041] Figure 12 A flowchart illustrating an embodiment of a control method for a variable frequency heat pump unit;

[0042] Figure 13 This is a flowchart illustrating another embodiment of the control method for a variable frequency heat pump unit.

[0043] Referring to the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows:

[0044] 102 - Acquisition unit; 104 - Control unit. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0046] Considering that fixed-frequency compressors generally do not have pressure sensors and rely solely on the on / off state of a high-pressure switch to control high pressure—shutting down when the pressure is high and restarting when it's low—variable-frequency compressors are generally equipped with high-pressure sensors. In addition to the high-pressure switch, they can also be used in conjunction with the compressor block diagram to control the compressor's operating range, ensuring unit reliability. Related solutions typically use a single high-pressure point to limit and reduce the compressor frequency. The pressure range control of variable-frequency heat pump units generally involves limiting and reducing the unit's frequency when a certain high-pressure threshold is exceeded to maintain a high-pressure level. However, this can easily lead to frequent high-pressure protection activation, affecting the unit's reliable operation.

[0047] Furthermore, during the control process of variable frequency heat pump units, changes in the load on the evaporator or condenser side, or excessive adjustments in the coordinated control of the electronic expansion valve and compressor frequency, can easily lead to high pressure exceeding the range. Typical variable frequency heat pump units only have frequency limiting, frequency reduction, and high-pressure protection, with no distinction between frequency limiting / reduction and high-pressure protection. If the high-pressure exceeds the frequency reduction pressure, even if the compressor frequency has reached the lower limit but not the high-pressure protection value, the unit will continue to operate at ultra-high pressure, or can only shut down when the pressure reaches the high-pressure protection level.

[0048] Therefore, the present invention proposes a control method for a variable frequency heat pump unit. It combines the compressor block diagram and high-pressure switch protection values ​​to divide multiple frequency reduction spaces in detail. It adopts a seven-fold pressure control method, including frequency limiting, normal speed frequency reduction, super compressor block diagram, rapid frequency reduction, rapid frequency reduction, super-fast frequency reduction, and high-pressure protection, to control the high pressure within a reasonable range, avoid frequent over-pressure operation and high-pressure protection of the unit, and ensure stable and reliable operation of the unit, ensuring that the unit operates within a safe range.

[0049] According to embodiments of the present invention, a control method for a variable frequency heat pump unit is provided, such as... Figure 1 The diagram shows a flow chart of an embodiment of the method of the present invention. The variable frequency heat pump unit includes a compressor; in the solution of the present invention, as... Figure 1As shown, the control method of the variable frequency heat pump unit includes steps S110 to S140.

[0050] In step S110, the high-pressure threshold of the compressor block diagram control is obtained (e.g., the high-pressure P in the compressor block diagram). 压缩机框图高压 And obtain the high-pressure protection pressure threshold of the compressor (such as the high-pressure protection pressure P of the compressor). 高压保护 The high-pressure threshold and the high-pressure protection threshold of the compressor can be preset according to the performance of the compressor.

[0051] In step S120, the high pressure range of the compressor is determined according to the high pressure threshold controlled by the block diagram of the compressor and the high pressure protection threshold of the compressor; wherein, the high pressure range of the compressor includes: pressure intervals, and the number of pressure intervals is two or more; corresponding to each of the two or more pressure intervals, a corresponding frequency reduction amplitude of the compressor and a residence time after frequency reduction according to the frequency reduction amplitude of the compressor are set.

[0052] In step S130, after the variable frequency heat pump unit is powered on and the compressor is turned on, the current high pressure of the compressor is obtained according to a preset sampling period. Specifically, the current exhaust pressure of the compressor's exhaust port is obtained as the current high pressure of the variable frequency heat pump unit, and the current frequency of the compressor is obtained.

[0053] In step S140, the current frequency of the compressor is controlled according to the current high pressure of the compressor and the high pressure range of the compressor, so as to adjust the current high pressure of the compressor to the high pressure range of the compressor, so that the variable frequency heat pump unit operates within the high pressure range of the compressor, thereby ensuring the stable and reliable operation of the variable frequency heat pump unit.

[0054] The present invention proposes a control method for a variable frequency heat pump unit, which sets a high pressure range with two or more pressure intervals. For example, by combining the compressor block diagram and the high pressure switch protection value, multiple frequency reduction spaces are divided in detail to control the high pressure within a reasonable range, avoid frequent over-pressure operation and high pressure protection of the unit, and ensure that the unit operates stably and reliably, ensuring that the unit operates within a safe range.

[0055] In some embodiments, the specific process of determining the high pressure range of the compressor in step S120 based on the high pressure threshold controlled by the compressor block diagram and the high pressure protection threshold of the compressor is described in the following exemplary description.

[0056] The following is combined Figure 2The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for determining the high pressure range of the compressor. It further illustrates the specific process of determining the high pressure range of the compressor in step S120, including steps S210 to S260.

[0057] Step S210: The difference between the block diagram control high-pressure threshold and the preset first pressure threshold of the compressor is determined as the frequency-limiting high-pressure threshold of the compressor, such as the compressor frequency-limiting high-pressure P. 高压限频＝ P 压缩机框图高压 -△P1. Wherein, the preset first pressure threshold is △P1.

[0058] Step S220: The difference between the high-pressure threshold controlled by the compressor block diagram and the preset second pressure threshold is determined as the first rate-reduced high-pressure threshold of the compressor, such as the compressor constant-speed reduced-frequency high-pressure threshold P. 高压常速降频＝ P 压缩机框图高压 -△P2. Wherein, the preset second pressure threshold is △P2.

[0059] Step S230: The sum of the high-pressure threshold controlled by the compressor block diagram and the preset third pressure threshold is determined as the second rate-reduction high-pressure threshold of the compressor, such as the compressor rapid rate-reduction high-pressure P. 高压快速降频＝ P 压缩机框图高压 +△P3. The preset third pressure threshold is △P3.

[0060] Step S240: The difference between the compressor's high-pressure protection threshold and the preset fourth pressure threshold is determined as the compressor's third-rate frequency reduction high-pressure threshold, such as the compressor's rapid frequency reduction high-pressure P. 高压急速降频＝ P 高压保护 -△P4. The preset fourth pressure threshold is △P4.

[0061] Step S250: Determine the fourth rate reduction high pressure threshold of the compressor by the difference between the high pressure protection threshold of the compressor and the preset fifth pressure threshold. For example, if the compressor rapidly reduces the frequency, the high pressure P... 高压飞速降频＝ P 高压保护 -△P5.

[0062] Step S260: Determine the high pressure range of the compressor based on the compressor's frequency-limited high pressure threshold, the compressor's block diagram control high pressure threshold, the compressor's first-rate frequency-reduced high pressure threshold, the compressor's second-rate frequency-reduced high pressure threshold, the compressor's third-rate frequency-reduced high pressure threshold, the compressor's fourth-rate frequency-reduced high pressure threshold, and the compressor's high pressure protection threshold. The high-pressure range of the compressor includes: a pressure interval divided by the following sequentially increasing pressure thresholds: the compressor's frequency-limited high-pressure threshold, the compressor's block diagram-controlled high-pressure threshold, the compressor's first-rate frequency-reduced high-pressure threshold, the compressor's second-rate frequency-reduced high-pressure threshold, the compressor's third-rate frequency-reduced high-pressure threshold, the compressor's fourth-rate frequency-reduced high-pressure threshold, and the compressor's high-pressure protection threshold. In other words, two or more of these pressure intervals are specifically defined by the following sequentially increasing pressure thresholds: the compressor's frequency-limited high-pressure threshold, the compressor's block diagram-controlled high-pressure threshold, the compressor's first-rate frequency-reduced high-pressure threshold, the compressor's second-rate frequency-reduced high-pressure threshold, the compressor's third-rate frequency-reduced high-pressure threshold, the compressor's fourth-rate frequency-reduced high-pressure threshold, and the compressor's high-pressure protection threshold.

[0063] In the scheme of this invention, the following definition is made: the high-pressure unit pressure monitored in real time by the high-pressure sensor is P. 高压压力 Compressor frequency limiting high pressure P 高压限频＝ P 压缩机框图高压 -△P1, compressor constant speed reduced frequency high pressure P 高压常速降频＝ P 压缩机框图高压 -△P2, compressor block diagram, high pressure P 压缩机框图高压 The compressor rapidly reduces its frequency and applies high-pressure P. 高压快速降频＝ P 压缩机框图高压 +△P3, compressor rapidly reduces frequency, high pressure P 高压急速降频＝ P 高压保护 -△P4, compressor rapidly reduces frequency, high pressure P 高压飞速降频＝ P 高压保护 -△P5, compressor high-pressure protection, high-pressure P 高压保护 Among them, the values ​​of △P1, △P2, △P3, △P4, and △P5 are all greater than 0, and it is necessary to satisfy the following principle to make the above calculation results comply with the principle. The high-pressure relationship is P 高压限频 <P 高压常速降频 <P 压缩机框图高压 <P 高压快速降频 <P 高压急速降频 <P 高压飞速降频 <P 高压保护 And with P 压缩机框图高压 (Compressor inherent characteristics) and P高压保护 (High pressure switch value) These two are reference benchmarks; set them according to the maximum pressure at which each can operate.

[0064] Figure 11 This is a schematic diagram of the compressor's frequency reduction pressure. (Example:) Figure 11 As shown, the high-pressure relationship is P 高压限频 <P 高压常速降频 <P 压缩机框图高压 <P 高压快速降频 <P 高压急速降频 <P 高压飞速降频 <P 高压保护 The pressure varies depending on the type of refrigerant. For example, for R32 refrigerant, the pressure value is P. 高压限频 (4300 kPa) < P 高压常速降频 (4350 kPa) < P 压缩机框图高压 (4400 kPa) < P 高压快速降频 (4450 kPa) < P 高压急速降频 (4500 kPa) < P 高压飞速降频 (4600 kPa) < P 高压保护 (4700 kPa).

[0065] In related solutions, variable frequency heat pump units typically reduce their frequency to maintain a high pressure level by exceeding a certain high pressure value, but this method is relatively simple. In contrast, the solution of this invention employs a seven-fold pressure control method: frequency limiting, constant-speed frequency reduction, super-compressor block diagram, rapid frequency reduction, extremely rapid frequency reduction, super-fast frequency reduction, and high-pressure protection. This method keeps the high pressure within a reasonable range, avoiding frequent over-pressure operation and high-pressure protection, thus ensuring stable and reliable operation of the unit.

[0066] Figure 12 This is a flowchart illustrating an embodiment of a control method for a variable frequency heat pump unit. Figure 13 This is a flowchart illustrating another embodiment of the control method for a variable frequency heat pump unit. (See attached diagram.) Figure 12 and Figure 13 As shown, the control method of the variable frequency heat pump unit includes: Step 1, after the compressor is started, the high-pressure sensor and high-pressure switch of the unit detect the high-pressure pressure, and then selectively execute at least one of steps 2, 3, 4, 5, 6, 7, and 8 according to the actual situation. Here, the high-pressure pressure is the pressure at the compressor exhaust port. The high-pressure sensor and high-pressure switch are used to detect the high-pressure pressure. The high-pressure sensor can detect the specific pressure value in real time; the high-pressure switch is simply a switch that acts as an on / off switch, that is, the high-pressure switch will open when the high-pressure pressure is greater than the high-pressure protection value, and the high-pressure switch will close again when the high-pressure pressure is lower than a certain pressure.

[0067] In the solution of this invention, multiple frequency reduction spaces are divided in detail by combining the compressor block diagram and the high-pressure switch protection value. A seven-fold pressure control method is adopted, which includes frequency limiting, normal speed frequency reduction, super compressor block diagram, rapid frequency reduction, rapid frequency reduction, high-speed frequency reduction, and high-pressure protection. Different frequency reduction amplitudes and dwell times are used according to each divided pressure range to control the high pressure within a reasonable range, avoid frequent over-pressure operation and high-pressure protection of the unit, ensure stable and reliable operation of the unit, and ensure that the unit operates within a safe range.

[0068] In related solutions, compressor frequency adjustment, electronic expansion valve operation, changes in evaporator and condenser side operating conditions, and extreme conditions such as low temperature and high humidity, high temperature and high humidity, and maximum operating temperature can all cause the high pressure to exceed the expected range, even triggering high pressure protection. Generally, the pressure is controlled within the high pressure protection -ΔP range, leaving a margin to prevent frequent high pressure protection. However, the solution of this invention, in order to precisely control the high pressure range, combines the compressor block diagram and high pressure switch characteristics, proposing a seven-fold pressure control method. It determines the frequency limit in advance based on different pressures, reduces the frequency in stages, and has a buffer judgment time for frequency reduction. This solves the problems of system instability caused by excessive or rapid frequency reduction and high pressure surges leading to high pressure protection, while also avoiding the problem of compressor wear due to frequent overshooting of the compressor block diagram, ensuring stable unit operation.

[0069] In this invention, a seven-fold pressure control method is employed, including frequency limiting, constant-speed frequency reduction, compressor block diagram adjustment, rapid frequency reduction, extremely rapid frequency reduction, high-speed frequency reduction, and high-pressure protection. This method keeps the pressure within a reasonable range, preventing frequent over-pressure operation and high-pressure protection. To determine the rationality of the frequency limiting and reduction pressure settings, the pressure values ​​for each fold are comprehensively determined using the compressor operation block diagram and high-pressure switch protection values. Different frequency reduction amplitudes and dwell times are applied according to the pressure of each defined interval to ensure that over-pressure operation and frequent high-pressure protection are avoided, thus ensuring stable and reliable unit operation.

[0070] In some embodiments, the high-pressure range of the compressor includes: a pressure interval divided by a series of increasing high-pressure thresholds: a frequency-limited high-pressure threshold, a block diagram controlled high-pressure threshold, a first-rate frequency-reduced high-pressure threshold, a second-rate frequency-reduced high-pressure threshold, a third-rate frequency-reduced high-pressure threshold, a fourth-rate frequency-reduced high-pressure threshold, and a high-pressure protection threshold. Step S140, controlling the current frequency of the compressor based on its current high-pressure and high-pressure range, includes a pressure control process under a preset frequency-limiting mode (e.g., a high-pressure frequency-limiting mode).

[0071] The following is combined Figure 3The schematic diagram shows an embodiment of pressure control under a preset frequency limiting mode (such as a high-voltage frequency limiting mode) in the method of the present invention. It further illustrates the specific process of pressure control under the preset frequency limiting mode (such as a high-voltage frequency limiting mode) in step S140, including steps S310 to S340.

[0072] Step S310: After the compressor starts, determine whether the current high pressure of the compressor is continuously detected to be greater than or equal to the compressor's frequency-limiting high pressure threshold and less than the compressor's first rate-reduction high pressure threshold within a first set time period under a preset frequency-limiting mode. The first set time period under the preset frequency-limiting mode is, for example, t in the frequency-limiting mode. 连续1 time.

[0073] Step S320: If it is determined that the current high-pressure of the compressor is continuously greater than or equal to the compressor's frequency-limiting high-pressure threshold and less than the compressor's first rate-reduction high-pressure threshold within a first set time period under the preset frequency-limiting mode, then the compressor is controlled to enter the preset frequency-limiting mode to limit the increase of the compressor's current frequency. Then, it is determined whether the current high-pressure of the compressor is continuously less than the compressor's frequency-limiting high-pressure threshold within a second set time period under the preset frequency-limiting mode. Of course, if it is determined that the current high-pressure of the compressor is not continuously greater than or equal to the compressor's frequency-limiting high-pressure threshold and less than the compressor's first rate-reduction high-pressure threshold within the first set time period under the preset frequency-limiting mode, then the compressor is controlled to maintain its current operation and return to the previous state to re-control the compressor's current frequency based on the compressor's current high-pressure and the compressor's high-pressure range. The second set time under the preset frequency-limiting mode is, for example, t in the frequency-limiting mode. 连续2 time.

[0074] Step S330: If it is determined that the current high pressure of the compressor is continuously less than the compressor's frequency-limiting high pressure threshold within a second set time period under the preset frequency-limiting mode, then after maintaining the compressor's current frequency for a third set time under the preset frequency-limiting mode, the compressor is controlled to exit the preset frequency-limiting mode to remove the restriction on the compressor's current frequency increase and restore the control over the compressor's current frequency increase and decrease. The third set time under the preset frequency-limiting mode is, for example, t under the frequency-limiting mode. 连续3 time.

[0075] Step S340: If it is determined that the current high pressure of the compressor is not lower than the high pressure threshold of the compressor within the second set time of the preset frequency limiting mode, then return to the previous step to re-control the current frequency of the compressor based on the current high pressure of the compressor and the high pressure range of the compressor.

[0076] like Figure 12 and Figure 13 As shown, the control method for the variable frequency heat pump unit also includes: Step 2, frequency-limiting pressure control method. Frequency limiting: When the high-pressure reaches a certain value, the compressor is not allowed to increase its frequency further. At this time, it is necessary to maintain the current frequency and limit the compressor frequency increase; the compressor frequency limiting high-pressure P 高压限频＝ P 压缩机框图高压 -△P1.

[0077] In step 2, after the compressor starts, if t continuously 连续1 Time detected P 高压限频 ≤P 高压压力 <P 高压常速降频 If the compressor's current frequency limit increases, then the compressor's current frequency limit will rise. If this continues for t... 连续2 Time detected P 高压压力 <P 高压限频 Maintain the current frequency F 当前 continuous t 连续3 After a certain time, the frequency limiting will be lifted, and normal control pressure will be restored without restrictions.

[0078] In the solution of this invention, by limiting the pressure through frequency control, when the high pressure reaches a certain value, the compressor is not allowed to increase the frequency. At this time, it is necessary to maintain the current frequency to limit the compressor frequency increase, limit the current frequency in advance to avoid the high pressure from overshooting, and reduce frequent start-stop and high pressure protection.

[0079] In some embodiments, the high-pressure range of the compressor includes: a pressure interval divided by a series of increasing high-pressure thresholds: a frequency-limited high-pressure threshold, a block diagram controlled high-pressure threshold, a first-rate frequency-reducing high-pressure threshold, a second-rate frequency-reducing high-pressure threshold, a third-rate frequency-reducing high-pressure threshold, a fourth-rate frequency-reducing high-pressure threshold, and a high-pressure protection threshold. Step S140, which controls the current frequency of the compressor based on its current high-pressure and high-pressure range, further includes a pressure control process under a preset first-rate frequency-reducing mode (e.g., a constant-speed frequency-limiting mode).

[0080] The following is combined Figure 4The schematic diagram shows an embodiment of pressure control in the method of the present invention under a preset first rate reduction mode (such as a constant speed frequency limiting mode), further illustrating the specific process of pressure control in step S140 under the preset first rate reduction mode (such as a constant speed frequency limiting mode), including steps S410 to S450.

[0081] Step S410: After the compressor starts, determine whether the current high-pressure pressure of the compressor is continuously detected to be greater than or equal to the first-rate-reduction high-pressure pressure threshold and less than the block diagram control high-pressure threshold of the compressor within a first set time period in the preset first-rate-reduction mode. The first set time period in the preset first-rate-reduction mode is, for example, t in the first-rate-reduction mode. 连续1 time.

[0082] Step S420: If it is determined that the current high pressure of the compressor is greater than or equal to the first rate reduction high pressure threshold of the compressor and less than the block diagram control high pressure threshold of the compressor within a first set time period under the preset first rate reduction mode, then the compressor is controlled to enter the preset first rate reduction mode to control the current frequency of the compressor to decrease by the preset first rate reduction value; then it is re-determined whether the current high pressure of the compressor is greater than or equal to the first rate reduction high pressure threshold of the compressor and less than the block diagram control high pressure threshold of the compressor within a first set time period under the preset first rate reduction mode: if so, the compressor is controlled to... The current frequency is reduced by a preset first rate reduction value every preset first rate reduction time interval; otherwise, the process returns to re-control the current frequency of the compressor based on the current high pressure of the compressor and the high pressure range of the compressor. Of course, if it is determined that the current high pressure of the compressor is not greater than or equal to the high pressure threshold of the compressor's first rate reduction within a first set time in the preset first rate reduction mode, and is less than the high pressure threshold of the compressor's first rate reduction, then the compressor is controlled to maintain its current operation, and the process returns to re-control the current frequency of the compressor based on the current high pressure of the compressor and the high pressure range of the compressor.

[0083] Step S430: After controlling the current frequency of the compressor to decrease by a preset first rate reduction value at preset first rate reduction intervals, determine whether the current high pressure of the compressor is continuously detected to be less than the high pressure threshold of the compressor at the first rate reduction within a second set time period under the preset first rate reduction mode. The second set time under the preset first rate reduction mode is, for example, t in the first rate reduction mode. 连续2 Time. The preset first rate downtime is t.降频时间 The preset first rate down-frequency value is as follows: ΔF 常速降频 .

[0084] Step S440: If it is determined that the current high pressure of the compressor is continuously less than the high pressure threshold of the compressor's first rate frequency reduction mode within a second set time during the preset first rate frequency reduction mode, then after maintaining the compressor's current frequency under the preset first rate frequency reduction mode for a third set time, the compressor is controlled to exit the preset first rate frequency reduction mode, thereby exiting the control of the compressor's current frequency reduction according to the preset first rate frequency reduction mode. Then, the compressor's current frequency is re-controlled based on the compressor's current high pressure and the compressor's high pressure range. The third set time under the preset first rate frequency reduction mode is, for example, t under the first rate frequency reduction mode. 连续3 time.

[0085] Step S450: If it is determined that the current high pressure of the compressor is not lower than the high pressure threshold of the compressor's first rate reduction mode within a second set time period without continuous detection, then return to re-control the current frequency of the compressor based on the current high pressure of the compressor and the high pressure range of the compressor.

[0086] like Figure 12 and Figure 13 As shown, the control method for variable frequency heat pump units also includes: Step 3, pressure control method for constant speed frequency reduction. Constant speed frequency reduction: When the high-pressure exceeds the frequency limit pressure and reaches the pressure for constant speed frequency reduction, the compressor is not allowed to increase the frequency further and must reduce the frequency at a certain speed to prevent the pressure from rising. Since there is still room between the high-pressure and the boundary, only a small frequency reduction ΔF is needed. 常速降频 ; Compressor constant speed reduced frequency high pressure P 高压常速降频＝ P 压缩机框图高压 -△P2.

[0087] In step 3, after the compressor starts, if t continuously 连续1 Time detected P 高压常速降频 ≤P 高压压力 <P 压缩机框图高压 When the condition is met for the first time, the frequency is immediately reduced by ΔF. 常速降频 If the frequency reduction still meets this condition, then F 当前 per t 降频时间 Reduce △F 常速降频 Adjust until continuous t 连续2 Time detected P 高压压力 <P 高压常速降频 Maintain the current frequency F 当前 continuous t 连续3After a certain period of time, exit normal speed frequency reduction and determine whether to resume normal control or enter frequency limiting control based on real-time monitoring pressure.

[0088] In the solution of this invention, through constant-speed frequency reduction pressure control, when the high-pressure exceeds the frequency limit pressure and reaches the constant-speed frequency reduction pressure, the compressor is not allowed to increase the frequency further, and the frequency must be reduced at a certain speed to prevent the pressure from rising too high. Since there is still room between the high-pressure and the boundary, only a small frequency reduction ΔF is needed. 常速降频 The frequency reduction is small, and the unit has high reliability.

[0089] In some embodiments, the high-pressure range of the compressor includes: a pressure interval divided by a series of increasing high-pressure thresholds: a frequency-limited high-pressure threshold, a block diagram control high-pressure threshold, a first-rate frequency-reducing high-pressure threshold, a second-rate frequency-reducing high-pressure threshold, a third-rate frequency-reducing high-pressure threshold, a fourth-rate frequency-reducing high-pressure threshold, and a high-pressure protection pressure threshold. Step S140, which controls the current frequency of the compressor based on its current high-pressure and high-pressure range, further includes a pressure control process under a preset block diagram control mode (such as a compressor block diagram control mode).

[0090] The following is combined Figure 5 The schematic diagram shown is a flowchart of an embodiment of pressure control in a preset block diagram control mode (such as compressor block diagram control mode) in the method of the present invention. It further illustrates the specific process of pressure control in the preset block diagram control mode (such as compressor block diagram control mode) in step S140, including steps S510 to S550.

[0091] Step S510: After the compressor starts, determine whether the current high-pressure of the compressor is continuously detected to be greater than or equal to the high-pressure threshold of the compressor's block diagram control and less than the high-pressure threshold of the compressor's second rate-reduction high-pressure within a first set time period under a preset block diagram control mode. The first set time under the preset block diagram control mode is, for example, t in the block diagram control mode. 连续1 time.

[0092] Step S520: If it is determined that the current high pressure of the compressor is continuously greater than or equal to the high pressure threshold of the compressor's block diagram control and less than the high pressure threshold of the compressor's second rate reduction, within a first set time period under the preset block diagram control mode, then the compressor is controlled to enter the preset block diagram control mode to control the current frequency of the compressor to decrease by the preset block diagram control reduction value; then it is re-determined whether the current high pressure of the compressor is continuously greater than or equal to the high pressure threshold of the compressor's block diagram control and less than the high pressure threshold of the compressor's second rate reduction: if so, the compressor is controlled... The current frequency is reduced by a preset block diagram control frequency reduction value every preset block diagram control time interval; otherwise, it returns to re-control the current frequency of the compressor based on the current high pressure of the compressor and the high pressure range of the compressor. Of course, if it is determined that the current high pressure of the compressor is not continuously detected to be greater than or equal to the high pressure threshold of the compressor block diagram control within the first set time of the preset block diagram control mode, and is less than the high pressure threshold of the compressor block diagram control, then the compressor is controlled to maintain its current operation, and it returns to re-control the current frequency of the compressor based on the current high pressure of the compressor and the high pressure range of the compressor.

[0093] Step S530: After controlling the current frequency of the compressor to decrease by a preset block diagram control frequency reduction value at preset block diagram control times, determine whether the current high pressure of the compressor is continuously detected to be less than the block diagram control high pressure threshold within a second set time period under the preset block diagram control mode. The second set time under the preset block diagram control mode is, for example, t in the block diagram control mode. 连续2 Time. The preset block diagram controls the time, such as t. 降频时间 The preset block diagram controls the frequency reduction value, such as ΔF. 常速降频 .

[0094] Step S540: If it is determined that the current high pressure of the compressor is continuously less than the high pressure threshold of the compressor under the preset block diagram control mode within a second set time, then after maintaining the current frequency of the compressor under the preset block diagram control mode for a third set time, the compressor is controlled to exit the preset block diagram control mode to stop controlling the compressor's current frequency to decrease according to the preset block diagram control mode. Then, the current frequency of the compressor is controlled again based on the current high pressure of the compressor and the high pressure range of the compressor. The third set time under the preset block diagram control mode is, for example, t in the block diagram control mode. 连续3 time.

[0095] Step S550: If it is determined that the current high-pressure pressure of the compressor is not continuously lower than the high-pressure pressure threshold of the compressor within the second set time of the preset block diagram control mode, and it is determined that the current high-pressure pressure of the compressor is not continuously lower than the high-pressure pressure threshold of the compressor within the continuous control time of the preset block diagram control mode, then the compressor is controlled to stop, and the variable frequency heat pump unit is controlled to stop. The continuous control within the preset block diagram control mode, such as t... 压缩机框图持续 .

[0096] like Figure 12 and Figure 13 As shown, the control method for the variable frequency heat pump unit also includes: Step 4, the pressure control method of the compressor block diagram. Compressor block diagram: The high-pressure has reached the limit of the compressor's allowable operating range. To ensure unit reliability, a pressure margin is reserved, and to prevent the high pressure from continuously surging, the unit reduces ΔF. 超框图降频 Frequency; High-pressure compressor block diagram; High-pressure P 压缩机框图高压 .

[0097] In step 4, after the compressor starts, if t continuously 连续1 Time detected P 压缩机框图高压 ≤P 高压压力 <P 高压快速降频 When the condition is met for the first time, the frequency is immediately reduced by ΔF. 超框图降频 If the frequency reduction still meets this condition, then F 当前 per t 降频时间 Reduce △F 超框图降频 Adjust until continuous t 连续2 Time detected P 高压压力 <P 压缩机框图高压 Maintain the current frequency F 当前 continuous t 连续3 After a certain time, exit the compressor block diagram control and determine whether to resume normal control or enter other pressure-limited frequency reduction control based on real-time pressure monitoring; if the pressure remains constant for t... 压缩机框图持续 If the high pressure remains under compressor block diagram control during the operating period, the unit will be shut down.

[0098] In the solution of this invention, through pressure control of the compressor block diagram, when the high pressure has reached the limit of the compressor's allowable operating range, in order to ensure the reliability of the unit, a pressure margin is reserved, and to prevent the high pressure from continuously rising, the unit reduces ΔF. 超框图降频 Frequency provides a buffer; if the high pressure continues to rise for a certain period of time, the unit's super compressor block diagram will shut down.

[0099] In related solutions, both the electronic expansion valve and the compressor frequency are adjusted simultaneously. With external operating conditions changing in real time, poor coordination and control can easily lead to excessively high pressure. In other words, over-adjustment of the electronic expansion valve or compressor frequency can easily cause high pressure to exceed the range. However, in the solution of this invention, a margin of adjustment is reserved before high pressure exceeds the range, preventing the unit from repeatedly triggering high pressure protection or reducing the frequency too quickly. Thus, the seven-fold pressure control method of this invention reduces the risk of over-adjustment and ensures reliable operation of the unit.

[0100] In some embodiments, the high-pressure range of the compressor includes: a pressure interval divided by a series of increasing high-pressure thresholds: a frequency-limiting high-pressure threshold, a block diagram-controlled high-pressure threshold, a first-rate frequency-reduction high-pressure threshold, a second-rate frequency-reduction high-pressure threshold, a third-rate frequency-reduction high-pressure threshold, a fourth-rate frequency-reduction high-pressure threshold, and a high-pressure protection pressure threshold. Step S140, which controls the current frequency of the compressor based on its current high-pressure and high-pressure range, further includes a pressure control process under a preset second-rate frequency-reduction mode (e.g., a rapid frequency-reduction mode).

[0101] The following is combined Figure 6 The schematic diagram shows an embodiment of pressure control under a preset second rate reduction mode (such as a fast reduction mode) in the method of the present invention. It further illustrates the specific process of pressure control under the preset second rate reduction mode (such as a fast reduction mode) in step S140, including steps S610 to S650.

[0102] Step S610: After the compressor starts, determine whether the current high-pressure pressure of the compressor is continuously detected to be greater than or equal to the high-pressure pressure threshold of the second-rate frequency reduction mode and less than the high-pressure pressure threshold of the third-rate frequency reduction mode within a first set time period of the preset second-rate frequency reduction mode. The first set time period of the preset second-rate frequency reduction mode is, for example, t in the second-rate frequency reduction mode. 连续1 time.

[0103] Step S620: If it is determined that the current high pressure of the compressor is greater than or equal to the high pressure threshold of the compressor's second rate frequency reduction mode and less than the high pressure threshold of the compressor's third rate frequency reduction mode within a first set time period continuously within the preset second rate frequency reduction mode, then the compressor is controlled to enter the preset second rate frequency reduction mode to control the current frequency of the compressor to decrease by the preset second rate frequency reduction value; then it is re-determined whether the current high pressure of the compressor is greater than or equal to the high pressure threshold of the compressor's second rate frequency reduction mode and less than the high pressure threshold of the compressor's third rate frequency reduction mode within the first set time period continuously within the preset second rate frequency reduction mode: if so, the compressor is controlled to enter the preset second rate frequency reduction mode to control the current frequency of the compressor to decrease by the preset second rate frequency reduction value; then it is re-determined whether the current high pressure of the compressor is greater than or equal to the high pressure threshold of the compressor's second rate frequency reduction mode and less than the high pressure threshold of the compressor's third rate frequency reduction mode. The compressor's current frequency is reduced by a preset second rate reduction value every preset second rate reduction time interval; otherwise, it returns to the previous state to re-control the compressor's current frequency based on the compressor's current high pressure and the compressor's high pressure range. Of course, if it is determined that the compressor's current high pressure is not greater than or equal to the compressor's second rate reduction high pressure threshold and is less than the compressor's second rate reduction high pressure threshold within a first set time in the preset second rate reduction mode, then the compressor is controlled to maintain its current operation, and it returns to the previous state to re-control the compressor's current frequency based on the compressor's current high pressure and the compressor's high pressure range.

[0104] Step S630: After controlling the current frequency of the compressor to decrease by a preset second rate reduction value at preset second rate reduction intervals, determine whether the current high pressure of the compressor is continuously detected to be less than the high pressure threshold of the compressor at the second rate reduction mode within a second set time period in the preset second rate reduction mode. The second set time period in the preset second rate reduction mode is, for example, t in the second rate reduction mode. 连续2 Time. The preset second rate down-frequency time is as follows: t 降频时间 The preset second rate down-frequency value is as follows: ΔF 常速降频 .

[0105] Step S640: If it is determined that the current high pressure of the compressor is continuously less than the high pressure threshold of the compressor under the preset second-rate frequency reduction mode within a second set time, then after maintaining the compressor's current frequency under the preset second-rate frequency reduction mode for a third set time, the compressor is controlled to exit the preset second-rate frequency reduction mode, thereby exiting the control of the compressor's current frequency reduction according to the preset second-rate frequency reduction mode. Then, the compressor's current frequency is re-controlled based on the compressor's current high pressure and the compressor's high pressure range. The third set time under the preset second-rate frequency reduction mode is, for example, t under the second-rate frequency reduction mode.连续3 time.

[0106] Step S650: If it is determined that the current high-pressure pressure of the compressor is not continuously lower than the high-pressure pressure threshold of the compressor's second-rate frequency reduction mode within a second set time period, and it is also determined that the current high-pressure pressure of the compressor is not continuously lower than the high-pressure pressure threshold of the compressor's second-rate frequency reduction mode within a continuous control time period, then the compressor is controlled to stop, and the variable frequency heat pump unit is controlled to stop. The continuous control within the preset second-rate frequency reduction mode is, for example, t... 快速降频持续 .

[0107] like Figure 12 and Figure 13 As shown, the control method for the variable frequency heat pump unit also includes: Step 5, the pressure control method for rapid frequency reduction. Rapid frequency reduction: The high-pressure has exceeded the limit of the compressor block diagram range, but not by much. To prevent further exceeding the range and to quickly bring the pressure back to the range of the compressor block diagram, the unit's frequency reduction is increased, reducing ΔF. 快速降频 ; Compressor rapidly reduces frequency and high pressure P 高压快速降频＝ P 压缩机框图高压 +△P3.

[0108] In step 5, after the compressor starts, if t continuously 连续1 Time detected P 高压快速降频 ≤P 高压压力 <P 高压急速降频 When the condition is met for the first time, the frequency is immediately reduced by ΔF. 快速降频 If the frequency reduction still meets this condition, then F 当前 per t 降频时间 Reduce △F 快速降频 Adjust until continuous t 连续2 Time detected P 高压压力 <P 高压快速降频 Maintain the current frequency F 当前 continuous t 连续3 After a certain time, exit the rapid frequency reduction control and determine whether to resume normal control or enter other pressure-limited frequency reduction control based on real-time pressure monitoring. If t continues... 快速降频持续 If the high voltage does not exit the rapid frequency reduction control during the operating period, the unit will be shut down.

[0109] In the solution of this invention, through rapid frequency reduction pressure control, the high pressure has exceeded the limit of the compressor block diagram range, but by a small margin, preventing further exceedance and allowing the pressure to quickly return to the range of the compressor block diagram. This increases the frequency reduction of the unit and reduces ΔF. 快速降频 If the high pressure continues to rise for a certain period of time, the unit's supercompressor will shut down.

[0110] In some embodiments, the high-pressure range of the compressor includes: a pressure interval divided by a series of increasing high-pressure thresholds: a frequency-limiting high-pressure threshold, a block diagram-controlled high-pressure threshold, a first-rate frequency-reduction high-pressure threshold, a second-rate frequency-reduction high-pressure threshold, a third-rate frequency-reduction high-pressure threshold, a fourth-rate frequency-reduction high-pressure threshold, and a high-pressure protection pressure threshold. Step S140, which controls the current frequency of the compressor based on its current high-pressure and high-pressure range, further includes a pressure control process under a preset third-rate frequency-reduction mode (e.g., a rapid frequency-reduction mode).

[0111] The following is combined Figure 7 The schematic diagram shows an embodiment of pressure control in a preset third rate reduction mode (such as rapid reduction mode) in the method of the present invention. It further illustrates the specific process of pressure control in the preset third rate reduction mode (such as rapid reduction mode) in step S140, including steps S710 to S750.

[0112] Step S710: After the compressor starts, determine whether the current high-pressure of the compressor is continuously detected to be greater than or equal to the high-pressure threshold of the compressor's third-rate frequency reduction mode and less than the high-pressure threshold of the compressor's fourth-rate frequency reduction mode within a first set time period of the preset third-rate frequency reduction mode. The first set time period of the preset third-rate frequency reduction mode is, for example, t in the third-rate frequency reduction mode. 连续1 time.

[0113] Step S720: If it is determined that the current high pressure of the compressor is greater than or equal to the high pressure threshold of the compressor's third-rate frequency reduction mode and less than the high pressure threshold of the compressor's fourth-rate frequency reduction mode within a first set time period continuously within the preset third-rate frequency reduction mode, then the compressor is controlled to enter the preset third-rate frequency reduction mode to control the current frequency of the compressor to decrease by the preset third-rate frequency reduction value; then it is re-determined whether the current high pressure of the compressor is greater than or equal to the high pressure threshold of the compressor's third-rate frequency reduction mode and less than the high pressure threshold of the compressor's fourth-rate frequency reduction mode within a first set time period continuously within the preset third-rate frequency reduction mode: if so, the compressor is controlled to enter the preset third-rate frequency reduction mode to control the current frequency of the compressor to decrease by the preset third-rate frequency reduction value; then it is re-determined whether the current high pressure of the compressor is greater than or equal to the high pressure threshold of the compressor's third-rate frequency reduction mode and less than the high pressure threshold of the compressor's fourth-rate frequency reduction mode. The compressor's current frequency is reduced by a preset third-rate reduction value every preset third-rate reduction time interval; otherwise, it returns to the previous state to re-control the compressor's current frequency based on the compressor's current high-pressure pressure and the compressor's high-pressure pressure range. Of course, if it is determined that the compressor's current high-pressure pressure is not greater than or equal to the compressor's third-rate reduction high-pressure pressure threshold and is less than the compressor's third-rate reduction high-pressure pressure threshold within a first set time in the preset third-rate reduction mode, then the compressor is controlled to maintain its current operation, and the process returns to the previous state to re-control the compressor's current frequency based on the compressor's current high-pressure pressure and the compressor's high-pressure pressure range.

[0114] Step S730: After controlling the current frequency of the compressor to decrease by a preset third rate reduction value at preset third rate reduction intervals, determine whether the current high pressure of the compressor is continuously detected to be less than the high pressure threshold of the compressor at the third rate reduction within a third set time period in the preset third rate reduction mode. The third set time period in the preset third rate reduction mode is, for example, t in the third rate reduction mode. 连续2 Time. The preset third rate down-frequency time is as follows: t 降频时间 The preset third rate down-frequency value is as follows: ΔF 常速降频 .

[0115] Step S740: If it is determined that the current high pressure of the compressor is continuously less than the high pressure threshold of the compressor's third-rate frequency reduction mode within a third set time period, then after maintaining the compressor's current frequency under the preset third-rate frequency reduction mode for a fourth time period, the compressor is controlled to exit the preset third-rate frequency reduction mode, thus exiting the control of the compressor's current frequency reduction according to the preset third-rate frequency reduction mode. Afterwards, the compressor's current frequency is re-controlled based on the compressor's current high pressure and the compressor's high pressure range. The fourth time period under the preset third-rate frequency reduction mode is, for example, t under the third-rate frequency reduction mode.连续3 time.

[0116] Step S750: If it is determined that the current high-pressure pressure of the compressor is not continuously lower than the high-pressure pressure threshold of the compressor's third-rate frequency reduction mode within a third set time period, and it is also determined that the current high-pressure pressure of the compressor is not continuously lower than the high-pressure pressure threshold of the compressor's third-rate frequency reduction mode within a continuous control time period, then the compressor is controlled to stop, and the variable frequency heat pump unit is controlled to stop. The continuous control within the preset third-rate frequency reduction mode is, for example, t... 急速降频持续 .

[0117] like Figure 12 and Figure 13 As shown, the control method for the variable frequency heat pump unit also includes: Step 6, the pressure control method for rapid frequency reduction. Rapid frequency reduction: If the high pressure has exceeded the limit of the compressor block diagram range by a certain amount, to prevent further exceeding the range, the unit immediately increases the frequency reduction amplitude ΔF. 急速降频 ; Compressor rapidly reduces frequency and high pressure P 高压急速降频＝ P 高压保护 -△P4.

[0118] In step 6, after the compressor starts, if t continuously 连续1 Time detected P 高压急速降频 ≤P 高压压力 <P 高压飞速降频 When the condition is met for the first time, the frequency is immediately reduced by ΔF. 急速降频 If the frequency reduction still meets this condition, then F 当前 per t 降频时间 Reduce △F 急速降频 Adjust until continuous t 连续2 Time detected P 高压压力 <P 高压急速降频 Maintain the current frequency F 当前 continuous t 连续3 After a certain time, exit the rapid frequency reduction control and determine whether to resume normal control or enter other pressure-limited frequency reduction control based on real-time pressure monitoring. If t continues... 急速降频持续 If the high voltage does not exit the rapid frequency reduction control during the operating period, the unit will be shut down.

[0119] In the solution of this invention, through rapid frequency reduction pressure control, when the high pressure has exceeded the limit of the compressor block diagram range by a certain amount, to prevent further exceeding the range, the unit immediately increases the frequency reduction amplitude ΔF. 急速降频 Allow the pressure to quickly return to the range shown in the compressor diagram. If the high pressure continues to rise for a certain period of time, the unit will shut down.

[0120] In some embodiments, the high-pressure range of the compressor includes: a pressure interval divided by a series of increasing high-pressure thresholds: a frequency-limiting high-pressure threshold, a block diagram-controlled high-pressure threshold, a first-rate frequency-reduction high-pressure threshold, a second-rate frequency-reduction high-pressure threshold, a third-rate frequency-reduction high-pressure threshold, a fourth-rate frequency-reduction high-pressure threshold, and a high-pressure protection pressure threshold. Step S140, which controls the current frequency of the compressor based on its current high-pressure and high-pressure range, further includes a pressure control process under a preset fourth-rate frequency-reduction mode (e.g., a rapid frequency-reduction mode).

[0121] The following is combined Figure 8 The schematic diagram shows an embodiment of pressure control in the preset fourth rate reduction mode (such as rapid reduction mode) of the method of the present invention, which further illustrates the specific process of pressure control in the preset fourth rate reduction mode (such as rapid reduction mode) in step S140, including steps S810 to S850.

[0122] Step S810: After the compressor starts, determine whether the current high-pressure of the compressor is continuously detected to be greater than or equal to the high-pressure threshold of the compressor's fourth-rate frequency reduction mode and less than the high-pressure protection threshold of the compressor within a first set time period of the preset fourth-rate frequency reduction mode. The first set time period of the preset fourth-rate frequency reduction mode is, for example, t in the fourth-rate frequency reduction mode. 连续1 time.

[0123] Step S820: If it is determined that the current high pressure of the compressor is greater than or equal to the high pressure threshold of the compressor's fourth-rate frequency reduction mode and less than the high pressure protection threshold of the compressor within a first set time period of the preset fourth-rate frequency reduction mode, then the compressor is controlled to enter the preset fourth-rate frequency reduction mode to control the current frequency of the compressor to decrease by the preset fourth-rate frequency reduction value; then it is re-determined whether the current high pressure of the compressor is greater than or equal to the high pressure threshold of the compressor's fourth-rate frequency reduction mode and less than the high pressure protection threshold of the compressor within a first set time period of the preset fourth-rate frequency reduction mode: if so, the compressor is controlled to... The current frequency is reduced by a preset fourth rate reduction value every preset fourth rate reduction time; otherwise, it returns to the previous state to re-control the current frequency of the compressor based on the current high pressure of the compressor and the high pressure range of the compressor. Of course, if it is determined that the current high pressure of the compressor is not greater than or equal to the high pressure threshold of the compressor's fourth rate reduction and is less than the high pressure threshold of the compressor's fourth rate reduction within the first set time of the preset fourth rate reduction mode, then the compressor is controlled to maintain the current operation, and it returns to the previous state to re-control the current frequency of the compressor based on the current high pressure of the compressor and the high pressure range of the compressor.

[0124] Step S830: After controlling the current frequency of the compressor to decrease by a preset fourth rate reduction value at preset fourth rate reduction intervals, determine whether the current high pressure of the compressor is continuously detected to be less than the high pressure threshold of the compressor at the fourth rate reduction mode within the fourth time interval of the preset fourth rate reduction mode. The fourth time interval of the preset fourth rate reduction mode is, for example, t in the fourth rate reduction mode. 连续2 Time. The preset fourth rate down-frequency time is as follows: t 降频时间 The preset fourth rate down-frequency value is as follows: ΔF 常速降频 .

[0125] Step S840: If it is determined that the current high-pressure of the compressor is continuously less than the high-pressure threshold of the compressor's fourth-rate frequency reduction mode within a fourth time period, then after maintaining the compressor's current frequency within the preset fourth-rate frequency reduction mode for a fourth time period, the compressor is controlled to exit the preset fourth-rate frequency reduction mode, thus exiting the control of the compressor's current frequency reduction according to the preset fourth-rate frequency reduction mode. Afterwards, the compressor's current frequency is re-controlled based on the compressor's current high-pressure pressure and the compressor's high-pressure pressure range. The fourth time period within the preset fourth-rate frequency reduction mode is, for example, t within the fourth-rate frequency reduction mode. 连续3 time.

[0126] Step S850: If it is determined that the current high-pressure pressure of the compressor is not continuously lower than the high-pressure pressure threshold of the compressor's fourth-rate frequency reduction mode within the fourth time period, and it is also determined that the current high-pressure pressure of the compressor is not continuously lower than the high-pressure pressure threshold of the compressor's fourth-rate frequency reduction mode within the continuous control time, then the compressor is controlled to stop, and the variable frequency heat pump unit is controlled to stop. Wherein, the continuous control within the preset fourth-rate frequency reduction mode is, for example, t... 飞速降频持续 .

[0127] like Figure 12 and Figure 13 As shown, the control method for the variable frequency heat pump unit also includes: Step 7, the pressure control method for rapid frequency reduction. Rapid frequency reduction: When the high pressure is about to reach the high pressure protection value, it is necessary to quickly reduce ΔF. 飞速降频 The compressor rapidly reduces its frequency and applies high-pressure P. 高压飞速降频＝ P 高压保护 -△P5.

[0128] In step 7, after the compressor starts, if t continuously 连续1 Time detected P 高压飞速降频 ≤P 高压压力 <P 高压保护 When the condition is met for the first time, the frequency is immediately reduced by ΔF. 飞速降频 If the frequency reduction still meets this condition, then F 当前 per t 降频时间 Reduce △F 飞速降频 Adjust until continuous t 连续2 Time detected P 高压压力 <P 高压飞速降频 Maintain the current frequency F 当前 continuous t 连续3 After a certain time, exit the rapid frequency reduction control and determine whether to resume normal control or enter other pressure-limited frequency reduction control based on real-time pressure monitoring. If t continues... 飞速降频持续 If the high voltage does not exit the rapid frequency reduction control during the operating period, the unit will be shut down.

[0129] The relationship between the frequency reduction amplitude and the frequency reduction amplitude is ΔF. 常速降频 <△F 超框图降频 <△F 快速降频 <△F 急速降频 <△F 飞速降频 For example: △F 常速降频 (2Hz)<△F 超框图降频 (4Hz)<△F 快速降频 (8Hz)<△F 急速降频 (10Hz)<△F 飞速降频 (12Hz).

[0130] The continuous runtime downtime relationship is t 压缩机框图持续 >t 快速降频持续 >t 急速降频持续 >t 飞速降频持续 For example: t 压缩机框图持续 (30min)>t 快速降频持续 (15min)>t 急速降频持续 (5min)>t 飞速降频持续 (3min).

[0131] In the solution of this invention, through rapid frequency reduction pressure control, when the high pressure is about to reach the high pressure protection value, it is necessary to quickly reduce ΔF. 飞速降频 See if the high pressure can be released. If the high pressure continues to rise for a certain period of time, the unit should be shut down.

[0132] In some embodiments, the high-pressure range of the compressor includes: a pressure interval divided by a series of progressively increasing high-pressure thresholds: a frequency-limited high-pressure threshold, a block diagram-controlled high-pressure threshold, a first-rate frequency-reducing high-pressure threshold, a second-rate frequency-reducing high-pressure threshold, a third-rate frequency-reducing high-pressure threshold, a fourth-rate frequency-reducing high-pressure threshold, and a high-pressure protection threshold. Step S140, which controls the current frequency of the compressor based on its current high-pressure and high-pressure range, further includes a pressure control process under a preset high-pressure protection mode.

[0133] The following is combined Figure 9 The schematic diagram shown is a flowchart of an embodiment of pressure control in a preset high-pressure protection mode in the method of the present invention. It further illustrates the specific process of pressure control in the preset high-pressure protection mode in step S140, including steps S910 to S920.

[0134] Step S910: After the compressor starts, determine whether the current high pressure of the compressor is continuously detected to be greater than or equal to the high pressure protection high pressure threshold of the compressor within a first set time period in the preset high pressure protection mode. The first set time period in the preset fourth rate frequency reduction mode is, for example, t in the fourth rate frequency reduction mode. 连续1 time.

[0135] Step S920: If it is determined that the current high pressure of the compressor is continuously greater than or equal to the high pressure protection threshold of the compressor within a first set time in the preset high pressure protection mode, then the high pressure switch of the variable frequency heat pump unit is controlled to open, and the variable frequency heat pump unit is controlled to stop. Of course, if it is determined that the current high pressure of the compressor is not continuously greater than or equal to the high pressure protection threshold of the compressor within the first set time in the preset high pressure protection mode, then the compressor is controlled to maintain its current operation, and the process is returned to re-control the current frequency of the compressor based on the current high pressure of the compressor and the high pressure range of the compressor.

[0136] like Figure 12 and Figure 13 As shown, the control method for the variable frequency heat pump unit also includes: step 8, pressure control method for high-pressure protection. High-pressure protection: If the high-pressure exceeds the protection value of the high-pressure switch, the unit will shut down due to a fault; the compressor high-pressure protection high-pressure P 高压保护 .

[0137] In step 8, after the compressor starts, if t continuously 连续1 Time detected P 高压压力 ≥P 高压保护 If the high-voltage switch is disconnected, the unit will shut down.

[0138] In the solution of this invention, the unit malfunctions and shuts down when the high pressure exceeds the protection value of the high pressure switch through pressure control of high pressure protection.

[0139] This invention proposes a seven-fold pressure control method, comprising frequency limiting, constant-speed frequency reduction, super-compressor block diagram, rapid frequency reduction, swift frequency reduction, high-speed frequency reduction, and high-pressure protection. Different frequency reduction amplitudes and dwell times are used for each defined pressure range to control the high pressure within a reasonable range. This solves the problem of excessive high pressure due to over-regulation of the electronic expansion valve or compressor frequency, avoids frequent over-pressure operation and high-pressure protection of the unit, and ensures stable and reliable operation of the unit.

[0140] The technical solution of this embodiment pre-sets seven pressure control zones for the variable frequency heat pump unit, including frequency limiting, normal speed frequency reduction, super compressor block diagram, rapid frequency reduction, rapid frequency reduction, super-rapid frequency reduction, and high-pressure protection. Different compressor frequency reduction amplitudes and dwell times are set for each pressure zone. After the compressor of the variable frequency heat pump unit is started, the high-pressure of the compressor is acquired. Based on the pressure zone to which the high-pressure of the compressor belongs, at least one of the following protections is applied to the compressor: frequency limiting, normal speed frequency reduction, super compressor block diagram, rapid frequency reduction, super-rapid frequency reduction, super-rapid frequency reduction, and high-pressure protection, to control the high-pressure of the compressor within the set reasonable pressure range. Therefore, by applying at least one of these protections to the compressor, the high-pressure of the compressor is controlled within the set reasonable pressure range, improving the reliability and safety of the unit's operation.

[0141] According to embodiments of the present invention, a control device for a variable frequency heat pump unit corresponding to a control method for a variable frequency heat pump unit is also provided. See also Figure 10 The diagram shows a structural schematic of an embodiment of the device of the present invention. The variable frequency heat pump unit includes a compressor; in the solution of the present invention, as... Figure 10 As shown, the control device of the variable frequency heat pump unit includes: an acquisition unit 102 and a control unit 104.

[0142] The acquisition unit 102 is configured to acquire the block diagram control high pressure threshold of the compressor (such as the high pressure P in the compressor block diagram). 压缩机框图高压 And obtain the high-pressure protection pressure threshold of the compressor (such as the high-pressure protection pressure P of the compressor). 高压保护 The high-pressure threshold and the high-pressure protection threshold of the compressor can be preset according to the performance of the compressor. For the specific functions and processing of the acquisition unit 102, please refer to step S110.

[0143] The control unit 104 is configured to control the high-pressure threshold and the high-pressure protection threshold of the compressor according to the block diagram of the compressor, and to determine the high-pressure range of the compressor. The high-pressure range of the compressor includes pressure intervals, and the number of pressure intervals is two or more. Corresponding to each of the two or more pressure intervals, a corresponding frequency reduction amplitude of the compressor and a residence time after frequency reduction according to the compressor's frequency reduction amplitude are set. For the specific functions and processing of the control unit 104, please refer to step S120.

[0144] The acquisition unit 102 is further configured to acquire the current high-pressure pressure of the compressor according to a preset sampling period after the variable frequency heat pump unit is powered on and the compressor is started. Specifically, it acquires the current exhaust pressure of the compressor's exhaust port as the current high-pressure pressure of the variable frequency heat pump unit, and acquires the current frequency of the compressor. The specific functions and processing of this acquisition unit 102 are further described in step S130.

[0145] The control unit 104 is further configured to control the current frequency of the compressor based on the current high pressure of the compressor and the high pressure range of the compressor, so as to adjust the current high pressure of the compressor to within the high pressure range of the compressor, thereby ensuring that the variable frequency heat pump unit operates within the high pressure range of the compressor and thus guaranteeing the stable and reliable operation of the variable frequency heat pump unit. The specific functions and processing of this control unit 104 are further described in step S140.

[0146] The present invention proposes a control method for a variable frequency heat pump unit, which sets a high pressure range with two or more pressure intervals. For example, by combining the compressor block diagram and the high pressure switch protection value, multiple frequency reduction spaces are divided in detail to control the high pressure within a reasonable range, avoid frequent over-pressure operation and high pressure protection of the unit, and ensure that the unit operates stably and reliably, ensuring that the unit operates within a safe range.

[0147] In some embodiments, the control unit 104 determines the high-pressure range of the compressor based on the high-pressure threshold controlled by the compressor block diagram and the high-pressure protection threshold of the compressor, including:

[0148] The control unit 104 is further configured to determine the difference between the block diagram control high pressure threshold of the compressor and a preset first pressure threshold as the frequency-limiting high pressure threshold of the compressor, such as the compressor frequency-limiting high pressure P. 高压限频＝ P 压缩机框图高压 -△P1. The specific functions and processing of the control unit 104 are further described in step S210. Among them, the preset first pressure threshold is △P1.

[0149] The control unit 104 is further configured to determine the difference between the high-pressure threshold of the compressor block diagram control and a preset second pressure threshold as the first rate-reduced high-pressure threshold of the compressor, such as the compressor constant-speed reduced-frequency high-pressure threshold P. 高压常速降频＝ P 压缩机框图高压 -△P2. The specific functions and processing of this control unit 104 are further explained in step S220. The preset second pressure threshold is △P2.

[0150] The control unit 104 is further configured to determine the sum of the block diagram control high pressure threshold and the preset third pressure threshold of the compressor as the second rate reduction high pressure threshold of the compressor, such as the compressor rapid rate reduction high pressure P. 高压快速降频＝ P 压缩机框图高压 +△P3. The specific functions and processing of this control unit 104 are further explained in step S230. The preset third pressure threshold is △P3.

[0151] The control unit 104 is further configured to determine the difference between the high-pressure protection pressure threshold of the compressor and a preset fourth pressure threshold as the third rate reduction high-pressure pressure threshold of the compressor, such as the compressor rapid rate reduction high-pressure P. 高压急速降频＝ P 高压保护 -△P4. The specific functions and processing of this control unit 104 are further explained in step S240. The preset fourth pressure threshold is △P4.

[0152] The control unit 104 is further configured to determine the fourth rate reduction high pressure threshold of the compressor by the difference between the high pressure protection pressure threshold of the compressor and a preset fifth pressure threshold, such as the compressor rapidly reducing the high pressure P. 高压飞速降频＝ P 高压保护 -△P5. For the specific functions and processing of the control unit 104, please refer to step S250.

[0153] The control unit 104 is further configured to determine the high-pressure range of the compressor based on the compressor's frequency-limited high-pressure threshold, the compressor's block diagram control high-pressure threshold, the compressor's first-rate frequency-reduced high-pressure threshold, the compressor's second-rate frequency-reduced high-pressure threshold, the compressor's third-rate frequency-reduced high-pressure threshold, the compressor's fourth-rate frequency-reduced high-pressure threshold, and the compressor's high-pressure protection threshold. The specific functions and processing of this control unit 104 are further described in step S260. The high-pressure range of the compressor includes: a pressure interval divided by the following sequentially increasing pressure thresholds: the compressor's frequency-limited high-pressure threshold, the compressor's block diagram-controlled high-pressure threshold, the compressor's first-rate frequency-reduced high-pressure threshold, the compressor's second-rate frequency-reduced high-pressure threshold, the compressor's third-rate frequency-reduced high-pressure threshold, the compressor's fourth-rate frequency-reduced high-pressure threshold, and the compressor's high-pressure protection threshold. In other words, two or more of these pressure intervals are specifically defined by the following sequentially increasing pressure thresholds: the compressor's frequency-limited high-pressure threshold, the compressor's block diagram-controlled high-pressure threshold, the compressor's first-rate frequency-reduced high-pressure threshold, the compressor's second-rate frequency-reduced high-pressure threshold, the compressor's third-rate frequency-reduced high-pressure threshold, the compressor's fourth-rate frequency-reduced high-pressure threshold, and the compressor's high-pressure protection threshold.

[0154] In the scheme of this invention, the following definition is made: the high-pressure unit pressure monitored in real time by the high-pressure sensor is P. 高压压力 Compressor frequency limiting high pressure P 高压限频＝ P 压缩机框图高压 -△P1, compressor constant speed reduced frequency high pressure P 高压常速降频＝ P 压缩机框图高压 -△P2, compressor block diagram, high pressure P 压缩机框图高压 The compressor rapidly reduces its frequency and applies high-pressure P. 高压快速降频＝ P 压缩机框图高压 +△P3, compressor rapidly reduces frequency, high pressure P 高压急速降频＝ P 高压保护 -△P4, compressor rapidly reduces frequency, high pressure P 高压飞速降频＝ P 高压保护 -△P5, compressor high-pressure protection, high-pressure P 高压保护 .

[0155] Figure 11 This is a schematic diagram of the compressor's frequency reduction pressure. (Example:) Figure 11 As shown, the high-pressure relationship is P 高压限频 <P 高压常速降频 <P 压缩机框图高压 <P 高压快速降频 <P 高压急速降频 <P高压飞速降频 <P 高压保护 The pressure varies depending on the type of refrigerant. For example, for R32 refrigerant, the pressure value is P. 高压限频 (4300 kPa) < P 高压常速降频 (4350 kPa) < P 压缩机框图高压 (4400 kPa) < P 高压快速降频 (4450 kPa) < P 高压急速降频 (4500 kPa) < P 高压飞速降频 (4600 kPa) < P 高压保护 (4700 kPa).

[0156] In related solutions, variable frequency heat pump units typically reduce their frequency to maintain a high pressure level by exceeding a certain high pressure value, but this method is relatively simple. In contrast, the solution of this invention employs a seven-fold pressure control method: frequency limiting, constant-speed frequency reduction, super-compressor block diagram, rapid frequency reduction, extremely rapid frequency reduction, super-fast frequency reduction, and high-pressure protection. This method keeps the high pressure within a reasonable range, avoiding frequent over-pressure operation and high-pressure protection, thus ensuring stable and reliable operation of the unit.

[0157] Figure 12 This is a flowchart illustrating an embodiment of a control method for a variable frequency heat pump unit. Figure 13 This is a flowchart illustrating another embodiment of the control method for a variable frequency heat pump unit. (See attached diagram.) Figure 12 and Figure 13 As shown, the control method of the variable frequency heat pump unit includes: Step 1, after the compressor is turned on, the high pressure sensor and high pressure switch of the unit detect the high pressure, and then selectively execute at least one of Step 2, Step 3, Step 4, Step 5, Step 6, Step 7, and Step 8 according to the actual situation.

[0158] In the solution of this invention, multiple frequency reduction spaces are divided in detail by combining the compressor block diagram and the high-pressure switch protection value. A seven-fold pressure control method is adopted, which includes frequency limiting, normal speed frequency reduction, super compressor block diagram, rapid frequency reduction, rapid frequency reduction, high-speed frequency reduction, and high-pressure protection. Different frequency reduction amplitudes and dwell times are used according to each divided pressure range to control the high pressure within a reasonable range, avoid frequent over-pressure operation and high-pressure protection of the unit, ensure stable and reliable operation of the unit, and ensure that the unit operates within a safe range.

[0159] In related solutions, compressor frequency adjustment, electronic expansion valve operation, changes in evaporator and condenser side operating conditions, and extreme conditions such as low temperature and high humidity, high temperature and high humidity, and maximum operating temperature can all cause the high pressure to exceed the expected range, even triggering high pressure protection. Generally, the pressure is controlled within the high pressure protection -ΔP range, leaving a margin to prevent frequent high pressure protection. However, the solution of this invention, in order to precisely control the high pressure range, combines the compressor block diagram and high pressure switch characteristics, proposing a seven-fold pressure control method. It determines the frequency limit in advance based on different pressures, reduces the frequency in stages, and has a buffer judgment time for frequency reduction. This solves the problems of system instability caused by excessive or rapid frequency reduction and high pressure surges leading to high pressure protection, while also avoiding the problem of compressor wear due to frequent overshooting of the compressor block diagram, ensuring stable unit operation.

[0160] In this invention, a seven-fold pressure control method is employed, including frequency limiting, constant-speed frequency reduction, compressor block diagram adjustment, rapid frequency reduction, extremely rapid frequency reduction, high-speed frequency reduction, and high-pressure protection. This method keeps the pressure within a reasonable range, preventing frequent over-pressure operation and high-pressure protection. To determine the rationality of the frequency limiting and reduction pressure settings, the pressure values ​​for each fold are comprehensively determined using the compressor operation block diagram and high-pressure switch protection values. Different frequency reduction amplitudes and dwell times are applied according to the pressure of each defined interval to ensure that over-pressure operation and frequent high-pressure protection are avoided, thus ensuring stable and reliable unit operation.

[0161] In some embodiments, the high-pressure range of the compressor includes a pressure interval defined by a series of increasing parameters: a frequency-limited high-pressure threshold of the compressor, a block diagram-controlled high-pressure threshold of the compressor, a first-rate frequency-reducing high-pressure threshold of the compressor, a second-rate frequency-reducing high-pressure threshold of the compressor, a third-rate frequency-reducing high-pressure threshold of the compressor, a fourth-rate frequency-reducing high-pressure threshold of the compressor, and a high-pressure protection pressure threshold of the compressor. The control unit 104 controls the current frequency of the compressor based on the current high-pressure and the high-pressure range of the compressor, including a pressure control process under a preset frequency-limiting mode (such as a high-pressure frequency-limiting mode), specifically as follows:

[0162] The control unit 104 is further configured to, after the compressor starts, determine whether, within a first set time period under a preset frequency limiting mode, the current high-pressure pressure of the compressor is continuously detected to be greater than or equal to the frequency limiting high-pressure pressure threshold of the compressor and less than the first rate reduction high-pressure pressure threshold of the compressor. The specific functions and processing of this control unit 104 are further described in step S310. The first set time under the preset frequency limiting mode is, for example, t in the frequency limiting mode. 连续1 time.

[0163] The control unit 104 is further configured to, if it is determined that the current high-pressure pressure of the compressor is continuously greater than or equal to the compressor's frequency-limiting high-pressure threshold and less than the compressor's first rate-reduction high-pressure threshold within a first set time period under a preset frequency-limiting mode, then control the compressor to enter a preset frequency-limiting mode to limit the increase of the compressor's current frequency; then determine whether the current high-pressure pressure of the compressor is continuously less than the compressor's frequency-limiting high-pressure threshold within a second set time period under the preset frequency-limiting mode; of course, if it is determined that the current high-pressure pressure of the compressor is not continuously greater than or equal to the compressor's frequency-limiting high-pressure threshold and less than the compressor's first rate-reduction high-pressure threshold within the first set time period under the preset frequency-limiting mode, then control the compressor to maintain its current operation and return to re-control the compressor's current frequency based on the compressor's current high-pressure pressure and the compressor's high-pressure pressure range. The second set time under the preset frequency-limiting mode is, for example, t in the frequency-limiting mode. 连续2 Time. For the specific functions and processing of the control unit 104, please refer to step S320.

[0164] The control unit 104 is further configured to, if it is determined that the current high pressure of the compressor is less than the compressor's frequency-limiting high pressure threshold within a second set time period under a preset frequency-limiting mode, then, after maintaining the compressor's current frequency for a third set time under the preset frequency-limiting mode, control the compressor to exit the preset frequency-limiting mode, thereby removing the restriction on the compressor's current frequency increase and restoring the control over the compressor's current frequency increase and decrease. The specific functions and processing of this control unit 104 are further described in step S330. The third set time under the preset frequency-limiting mode is, for example, t under the frequency-limiting mode. 连续3 time.

[0165] The control unit 104 is further configured to, if it is determined that the current high pressure of the compressor is not continuously detected to be lower than the compressor's frequency-limiting high pressure threshold within a second set time period under the preset frequency-limiting mode, return to re-control the compressor's current frequency based on the compressor's current high pressure and the compressor's high pressure range. The specific functions and processing of this control unit 104 are further described in step S340.

[0166] like Figure 12 and Figure 13 As shown, the control method for the variable frequency heat pump unit also includes: Step 2, frequency-limiting pressure control method. Frequency limiting: When the high-pressure reaches a certain value, the compressor is not allowed to increase its frequency further. At this time, it is necessary to maintain the current frequency and limit the compressor frequency increase; the compressor frequency limiting high-pressure P 高压限频＝ P 压缩机框图高压-△P1.

[0167] In step 2, after the compressor starts, if t continuously 连续1 Time detected P 高压限频 ≤P 高压压力 <P 高压常速降频 If the compressor's current frequency limit increases, then the compressor's current frequency limit will rise. If this continues for t... 连续2 Time detected P 高压压力 <P 高压限频 Maintain the current frequency F 当前 continuous t 连续3 After a certain time, the frequency limiting will be lifted, and normal control pressure will be restored without restrictions.

[0168] In the solution of this invention, by limiting the pressure through frequency control, when the high pressure reaches a certain value, the compressor is not allowed to increase the frequency. At this time, it is necessary to maintain the current frequency to limit the compressor frequency increase, limit the current frequency in advance to avoid the high pressure from overshooting, and reduce frequent start-stop and high pressure protection.

[0169] In some embodiments, the high-pressure range of the compressor includes a pressure interval defined by a series of progressively increasing high-pressure thresholds: a frequency-limited high-pressure threshold, a block diagram-controlled high-pressure threshold, a first-rate frequency-reduction high-pressure threshold, a second-rate frequency-reduction high-pressure threshold, a third-rate frequency-reduction high-pressure threshold, a fourth-rate frequency-reduction high-pressure threshold, and a high-pressure protection pressure threshold. The control unit 104 controls the current frequency of the compressor based on its current high-pressure and the high-pressure range, and further includes a pressure control process under a preset first-rate frequency-reduction mode (e.g., a constant-speed frequency-limited mode), as detailed below:

[0170] The control unit 104 is further configured to, after the compressor starts, determine whether, within a preset first-rate frequency reduction mode, the current high-pressure pressure of the compressor is continuously detected to be greater than or equal to the first-rate frequency reduction high-pressure pressure threshold of the compressor and less than the block diagram control high-pressure pressure threshold of the compressor. The specific functions and processing of this control unit 104 are further described in step S410. The preset first-rate frequency reduction mode, such as t in the first-rate frequency reduction mode... 连续1 time.

[0171] The control unit 104 is further configured to, if it is determined that the current high pressure of the compressor is greater than or equal to the first rate reduction high pressure threshold of the compressor and less than the block diagram control high pressure threshold of the compressor within a first set time period under the preset first rate reduction mode, control the compressor to enter the preset first rate reduction mode to control the current frequency of the compressor to decrease by the preset first rate reduction value; then, it re-determines whether the current high pressure of the compressor is greater than or equal to the first rate reduction high pressure threshold of the compressor and less than the block diagram control high pressure threshold of the compressor within a first set time period under the preset first rate reduction mode: if so .... The compressor's current frequency is reduced by a preset first rate reduction value every preset first rate reduction time interval; otherwise, the process returns to re-control the compressor's current frequency based on the compressor's current high pressure and the compressor's high pressure range. Of course, if it is determined that the compressor's current high pressure is not continuously greater than or equal to the compressor's first rate reduction high pressure threshold and is not less than the compressor's first rate reduction high pressure threshold within a first set time in the preset first rate reduction mode, then the compressor is controlled to maintain its current operation, and the process returns to re-control the compressor's current frequency based on the compressor's current high pressure and the compressor's high pressure range. The specific functions and processing of this control unit 104 are also described in step S420.

[0172] The control unit 104 is further configured to, after controlling the compressor's current frequency to decrease by a preset first rate reduction value at preset first rate reduction intervals, determine whether the compressor's current high-pressure pressure is continuously detected to be less than the compressor's first rate reduction high-pressure pressure threshold within a second set time period under the preset first rate reduction mode. The specific functions and processing of this control unit 104 are further described in step S430. The second set time under the preset first rate reduction mode is, for example, t in the first rate reduction mode. 连续2 Time. The preset first rate downtime is t. 降频时间 The preset first rate down-frequency value is as follows: ΔF 常速降频 .

[0173] The control unit 104 is further configured to, if it is determined that the current high pressure of the compressor is less than the high pressure threshold of the compressor's first rate frequency reduction mode within a second set time continuously during the preset first rate frequency reduction mode, then, after maintaining the compressor's current frequency under the preset first rate frequency reduction mode for a third set time, control the compressor to exit the preset first rate frequency reduction mode, thereby exiting the control of the compressor's current frequency reduction according to the preset first rate frequency reduction mode, and then re-controlling the compressor's current frequency based on the compressor's current high pressure and the compressor's high pressure range. The specific functions and processing of this control unit 104 are further described in step S440. The third set time under the preset first rate frequency reduction mode is, for example, t under the first rate frequency reduction mode. 连续3 time.

[0174] The control unit 104 is further configured to, if it is determined that the current high pressure of the compressor is not continuously detected to be lower than the first high pressure threshold of the compressor within a second set time in the preset first rate reduction mode, return to re-control the current frequency of the compressor based on the current high pressure of the compressor and the high pressure range of the compressor. The specific functions and processing of this control unit 104 are further described in step S450.

[0175] like Figure 12 and Figure 13 As shown, the control method for variable frequency heat pump units also includes: Step 3, pressure control method for constant speed frequency reduction. Constant speed frequency reduction: When the high-pressure exceeds the frequency limit pressure and reaches the pressure for constant speed frequency reduction, the compressor is not allowed to increase the frequency further and must reduce the frequency at a certain speed to prevent the pressure from rising. Since there is still room between the high-pressure and the boundary, only a small frequency reduction ΔF is needed. 常速降频 ; Compressor constant speed reduced frequency high pressure P 高压常速降频＝ P 压缩机框图高压 -△P2.

[0176] In step 3, after the compressor starts, if t continuously 连续1 Time detected P 高压常速降频 ≤P 高压压力 <P 压缩机框图高压 When the condition is met for the first time, the frequency is immediately reduced by ΔF. 常速降频 If the frequency reduction still meets this condition, then F 当前 per t 降频时间 Reduce △F 常速降频 Adjust until continuous t 连续2 Time detected P 高压压力 <P 高压常速降频 Maintain the current frequency F 当前 continuous t 连续3After a certain period of time, exit normal speed frequency reduction and determine whether to resume normal control or enter frequency limiting control based on real-time monitoring pressure.

[0177] In the solution of this invention, through constant-speed frequency reduction pressure control, when the high-pressure exceeds the frequency limit pressure and reaches the constant-speed frequency reduction pressure, the compressor is not allowed to increase the frequency further, and the frequency must be reduced at a certain speed to prevent the pressure from rising too high. Since there is still room between the high-pressure and the boundary, only a small frequency reduction ΔF is needed. 常速降频 The frequency reduction is small, and the unit has high reliability.

[0178] In some embodiments, the high-pressure range of the compressor includes: a pressure interval divided by a series of progressively increasing high-pressure thresholds: a frequency-limited high-pressure threshold, a block diagram controlled high-pressure threshold, a first-rate frequency-reduced high-pressure threshold, a second-rate frequency-reduced high-pressure threshold, a third-rate frequency-reduced high-pressure threshold, a fourth-rate frequency-reduced high-pressure threshold, and a high-pressure protection threshold. The control unit 104 controls the current frequency of the compressor based on its current high-pressure and the high-pressure range, and further includes a pressure control process under a preset block diagram control mode (such as a compressor block diagram control mode), as detailed below:

[0179] The control unit 104 is further configured to, after the compressor starts, determine whether, within a first set time period under a preset block diagram control mode, the current high-pressure pressure of the compressor is continuously detected to be greater than or equal to the block diagram control high-pressure pressure threshold of the compressor and less than the second rate-reduction high-pressure pressure threshold of the compressor. The specific functions and processing of this control unit 104 are further described in step S510. The first set time under the preset block diagram control mode is, for example, t in the block diagram control mode. 连续1 time.

[0180] The control unit 104 is further configured to, if it is determined that the current high pressure of the compressor is greater than or equal to the block control high pressure threshold of the compressor and less than the second rate reduction high pressure threshold of the compressor within a first set time period under a preset block control mode, control the compressor to enter a preset block control mode to control the current frequency of the compressor to decrease by a preset block control reduction value; then, it re-determines whether the current high pressure of the compressor is greater than or equal to the block control high pressure threshold of the compressor and less than the second rate reduction high pressure threshold of the compressor within the first set time period under the preset block control mode: if so, it controls the compressor to enter a preset block control mode to control the current frequency of the compressor to decrease by a preset block control reduction value; then it re-determines whether the current high pressure of the compressor is greater than or equal to the block control high pressure threshold of the compressor and less than the second rate reduction high pressure threshold of the compressor within a first set time period under the preset block control mode: if so, it controls the compressor to enter a preset block control mode to control the current frequency of the compressor to decrease by a preset block control reduction value. The compressor's current frequency is reduced by a preset block diagram control frequency reduction value every preset block diagram control time interval; otherwise, it returns to the previous state to re-control the compressor's current frequency based on the compressor's current high pressure and the compressor's high pressure range. Of course, if it is determined that the compressor's current high pressure is not continuously greater than or equal to the compressor's block diagram control high pressure threshold and is not less than the compressor's block diagram control high pressure threshold within a first set time in the preset block diagram control mode, then the compressor is controlled to maintain its current operation, and the process returns to the previous state to re-control the compressor's current frequency based on the compressor's current high pressure and the compressor's high pressure range. The specific functions and processing of this control unit 104 are also described in step S520.

[0181] The control unit 104 is further configured to, after controlling the current frequency of the compressor to decrease by a preset block diagram control frequency reduction value at preset block diagram control times, determine whether the current high pressure of the compressor is continuously detected to be less than the block diagram control high pressure threshold within a second set time period under the preset block diagram control mode. The specific functions and processing of this control unit 104 are further described in step S530. The second set time under the preset block diagram control mode is, for example, t in the block diagram control mode. 连续2 Time. The preset block diagram controls the time, such as t. 降频时间 The preset block diagram controls the frequency reduction value, such as ΔF. 常速降频 .

[0182] The control unit 104 is further configured to, if it is determined that the current high pressure of the compressor is less than the high pressure threshold of the compressor under the preset block diagram control mode for a second set time consecutively within the second set time, maintain the current frequency of the compressor under the preset block diagram control mode for a third set time, then control the compressor to exit the preset block diagram control mode, thereby exiting the frequency reduction control of the compressor under the preset block diagram control mode, and then re-controlling the current frequency of the compressor based on the current high pressure of the compressor and the high pressure range of the compressor. The specific functions and processing of this control unit 104 are further described in step S540. The third set time under the preset block diagram control mode is, for example, t under the block diagram control mode. 连续3 time.

[0183] The control unit 104 is further configured to, if it is determined that the current high-pressure pressure of the compressor is not continuously lower than the high-pressure pressure threshold of the compressor within a second set time period under the preset block diagram control mode, and it is determined that the current high-pressure pressure of the compressor is not continuously lower than the high-pressure pressure threshold of the compressor within a continuous control time period under the preset block diagram control mode, then control the compressor to stop and control the variable frequency heat pump unit to stop. The specific functions and processing of this control unit 104 are further described in step S550. The continuous control under the preset block diagram control mode, such as t... 压缩机框图持续 .

[0184] like Figure 12 and Figure 13 As shown, the control method for the variable frequency heat pump unit also includes: Step 4, the pressure control method of the compressor block diagram. Compressor block diagram: The high-pressure has reached the limit of the compressor's allowable operating range. To ensure unit reliability, a pressure margin is reserved, and to prevent the high pressure from continuously surging, the unit reduces ΔF. 超框图降频 Frequency; High-pressure compressor block diagram; High-pressure P 压缩机框图高压 .

[0185] In step 4, after the compressor starts, if t continuously 连续1 Time detected P 压缩机框图高压 ≤P 高压压力 <P 高压快速降频 When the condition is met for the first time, the frequency is immediately reduced by ΔF. 超框图降频 If the frequency reduction still meets this condition, then F 当前 per t 降频时间 Reduce △F 超框图降频 Adjust until continuous t 连续2 Time detected P 高压压力 <P 压缩机框图高压 Maintain the current frequency F 当前 continuous t 连续3After a certain time, exit the compressor block diagram control and determine whether to resume normal control or enter other pressure-limited frequency reduction control based on real-time pressure monitoring; if the pressure remains constant for t... 压缩机框图持续 If the high pressure remains under compressor block diagram control during the operating period, the unit will be shut down.

[0186] In the solution of this invention, through pressure control of the compressor block diagram, when the high pressure has reached the limit of the compressor's allowable operating range, in order to ensure the reliability of the unit, a pressure margin is reserved, and to prevent the high pressure from continuously rising, the unit reduces ΔF. 超框图降频 Frequency provides a buffer; if the high pressure continues to rise for a certain period of time, the unit's super compressor block diagram will shut down.

[0187] In related solutions, both the electronic expansion valve and the compressor frequency are adjusted simultaneously. With external operating conditions changing in real time, poor coordination and control can easily lead to excessively high pressure. In other words, over-adjustment of the electronic expansion valve or compressor frequency can easily cause high pressure to exceed the range. However, in the solution of this invention, a margin of adjustment is reserved before high pressure exceeds the range, preventing the unit from repeatedly triggering high pressure protection or reducing the frequency too quickly. Thus, the seven-fold pressure control method of this invention reduces the risk of over-adjustment and ensures reliable operation of the unit.

[0188] In some embodiments, the high-pressure range of the compressor includes: a pressure interval divided by a series of increasing high-pressure thresholds: a frequency-limiting high-pressure threshold, a block diagram-controlled high-pressure threshold, a first-rate frequency-reduction high-pressure threshold, a second-rate frequency-reduction high-pressure threshold, a third-rate frequency-reduction high-pressure threshold, a fourth-rate frequency-reduction high-pressure threshold, and a high-pressure protection pressure threshold. The control unit 104 controls the current frequency of the compressor based on its current high-pressure and the high-pressure range, and further includes a pressure control process under a preset second-rate frequency-reduction mode (e.g., a rapid frequency-reduction mode), as detailed below:

[0189] After the compressor starts, it is determined whether the current high pressure of the compressor is continuously detected to be greater than or equal to the high pressure threshold of the second rate frequency reduction mode and less than the high pressure threshold of the third rate frequency reduction mode within a first set time period of the preset second rate frequency reduction mode. The specific functions and processing of this control unit 104 are further described in step S610. The first set time period of the preset second rate frequency reduction mode is, for example, t in the second rate frequency reduction mode. 连续1 time.

[0190] The control unit 104 is further configured to, if it is determined that the current high pressure of the compressor is greater than or equal to the second-rate frequency reduction high pressure threshold and less than the third-rate frequency reduction high pressure threshold of the compressor within a first set time period under the preset second-rate frequency reduction mode, control the compressor to enter the preset second-rate frequency reduction mode to control the current frequency of the compressor to decrease by the preset second-rate frequency reduction value; then, it re-determines whether the current high pressure of the compressor is greater than or equal to the second-rate frequency reduction high pressure threshold and less than the third-rate frequency reduction high pressure threshold of the compressor within the first set time period under the preset second-rate frequency reduction mode: if so, control the compressor to enter the preset second-rate frequency reduction mode to control the current frequency of the compressor to decrease by the preset second-rate frequency reduction value; then, it re-determines whether the current high pressure of the compressor is greater than or equal to the second-rate frequency reduction high pressure threshold and less than the third-rate frequency reduction high pressure threshold of the compressor within a first set time period under the preset second-rate frequency reduction mode: if so, control the compressor to enter the preset second-rate frequency reduction mode to control the current frequency of the compressor to decrease by the preset second-rate frequency reduction value; then, it re-determines whether the current high pressure of the compressor is greater than or equal to the second-rate frequency reduction high pressure threshold and less than the third-rate frequency reduction high pressure threshold of the compressor. The compressor's current frequency is reduced by a preset second-rate frequency reduction value at preset second-rate reduction intervals; otherwise, the process returns to re-control the compressor's current frequency based on the compressor's current high-pressure and high-pressure range. If it is determined that the compressor's current high-pressure is not continuously greater than or equal to the compressor's second-rate frequency reduction high-pressure threshold and is not less than the compressor's second-rate frequency reduction high-pressure threshold within a first set time in the preset second-rate frequency reduction mode, the compressor is controlled to maintain its current operation, and the process returns to re-control the compressor's current frequency based on the compressor's current high-pressure and high-pressure range. The specific functions and processing of this control unit 104 are further described in step S620.

[0191] The control unit 104 is further configured to, after controlling the compressor's current frequency to decrease by a preset second rate reduction value at preset second rate reduction intervals, determine whether the compressor's current high-pressure pressure is continuously detected to be less than the compressor's second rate reduction high-pressure pressure threshold within a second set time period under the preset second rate reduction mode. The specific functions and processing of this control unit 104 are further described in step S630. The second set time under the preset second rate reduction mode is, for example, t in the second rate reduction mode. 连续2 Time. The preset second rate down-frequency time is as follows: t 降频时间 The preset second rate down-frequency value is as follows: ΔF 常速降频 .

[0192] The control unit 104 is further configured to, if it is determined that the current high pressure of the compressor is less than the high pressure threshold of the compressor under the preset second-rate frequency reduction mode for a second set time consecutively within the second set time, maintain the compressor's current frequency under the preset second-rate frequency reduction mode for a third set time, then control the compressor to exit the preset second-rate frequency reduction mode, thereby exiting the control of the compressor's current frequency reduction according to the preset second-rate frequency reduction mode, and then re-controlling the compressor's current frequency based on the compressor's current high pressure and the compressor's high pressure range. The specific functions and processing of this control unit 104 are further described in step S640. The preset third set time under the second-rate frequency reduction mode is, for example, t under the second-rate frequency reduction mode. 连续3 time.

[0193] The control unit 104 is further configured to, if it is determined that the current high-pressure pressure of the compressor is not continuously lower than the second-rate frequency reduction high-pressure pressure threshold of the compressor within a second set time period under the preset second-rate frequency reduction mode, and it is determined that the current high-pressure pressure of the compressor is not continuously lower than the second-rate frequency reduction high-pressure pressure threshold of the compressor within a continuous control time period under the preset second-rate frequency reduction mode, then control the compressor to stop and control the variable frequency heat pump unit to stop. The specific functions and processing of this control unit 104 are further described in step S650. The continuous control within the preset second-rate frequency reduction mode, such as t... 快速降频持续 .

[0194] like Figure 12 and Figure 13 As shown, the control method for the variable frequency heat pump unit also includes: Step 5, the pressure control method for rapid frequency reduction. Rapid frequency reduction: The high-pressure has exceeded the limit of the compressor block diagram range, but not by much. To prevent further exceeding the range and to quickly bring the pressure back to the range of the compressor block diagram, the unit's frequency reduction is increased, reducing ΔF. 快速降频 ; Compressor rapidly reduces frequency and high pressure P 高压快速降频＝ P 压缩机框图高压 +△P3.

[0195] In step 5, after the compressor starts, if t continuously 连续1 Time detected P 高压快速降频 ≤P 高压压力 <P 高压急速降频 When the condition is met for the first time, the frequency is immediately reduced by ΔF. 快速降频 If the frequency reduction still meets this condition, then F 当前 per t 降频时间 Reduce △F 快速降频 Adjust until continuous t 连续2 Time detected P 高压压力 <P高压快速降频 Maintain the current frequency F 当前 continuous t 连续3 After a certain time, exit the rapid frequency reduction control and determine whether to resume normal control or enter other pressure-limited frequency reduction control based on real-time pressure monitoring. If t continues... 快速降频持续 If the high voltage does not exit the rapid frequency reduction control during the operating period, the unit will be shut down.

[0196] In the solution of this invention, through rapid frequency reduction pressure control, the high pressure has exceeded the limit of the compressor block diagram range, but by a small margin, preventing further exceedance and allowing the pressure to quickly return to the range of the compressor block diagram. This increases the frequency reduction of the unit and reduces ΔF. 快速降频 If the high pressure continues to rise for a certain period of time, the unit's supercompressor will shut down.

[0197] In some embodiments, the high-pressure range of the compressor includes a pressure interval defined by a series of increasing parameters: a frequency-limiting high-pressure threshold of the compressor, a block diagram-controlled high-pressure threshold of the compressor, a first-rate frequency-reduction high-pressure threshold of the compressor, a second-rate frequency-reduction high-pressure threshold of the compressor, a third-rate frequency-reduction high-pressure threshold of the compressor, a fourth-rate frequency-reduction high-pressure threshold of the compressor, and a high-pressure protection pressure threshold of the compressor. The control unit 104 controls the current frequency of the compressor based on the current high-pressure and the high-pressure range of the compressor, and further includes a pressure control process under a preset third-rate frequency-reduction mode (e.g., rapid frequency-reduction mode), as follows:

[0198] The control unit 104 is further configured to, after the compressor starts, determine whether, within a first set time period under a preset third-rate frequency reduction mode, the current high-pressure pressure of the compressor is continuously detected to be greater than or equal to the third-rate frequency reduction high-pressure pressure threshold and less than the fourth-rate frequency reduction high-pressure pressure threshold. The specific functions and processing of this control unit 104 are further described in step S710. The first set time under the preset third-rate frequency reduction mode is, for example, t under the third-rate frequency reduction mode. 连续1 time.

[0199] The control unit 104 is further configured to, if it is determined that the current high pressure of the compressor is greater than or equal to the high pressure threshold of the compressor's third-rate frequency reduction mode and less than the high pressure threshold of the compressor's fourth-rate frequency reduction mode within a first set time period continuously during the preset third-rate frequency reduction mode, control the compressor to enter the preset third-rate frequency reduction mode to control the compressor's current frequency to decrease by the preset third-rate frequency reduction value; then, it re-determines whether the current high pressure of the compressor is greater than or equal to the high pressure threshold of the compressor's third-rate frequency reduction mode and less than the high pressure threshold of the compressor's fourth-rate frequency reduction mode within the first set time period continuously during the preset third-rate frequency reduction mode: if so, control the compressor to enter the preset third-rate frequency reduction mode to control the compressor's current frequency to decrease by the preset third-rate frequency reduction value; then, it re-determines whether the current high pressure of the compressor is greater than or equal to the high pressure threshold of the compressor's third-rate frequency reduction mode and less than the high pressure threshold of the compressor's fourth-rate frequency reduction mode. The compressor's current frequency is reduced by a preset third-rate frequency reduction value at preset third-rate reduction intervals; otherwise, the process returns to re-control the compressor's current frequency based on the compressor's current high-pressure and its high-pressure range. If it is determined that the compressor's current high-pressure is not continuously greater than or equal to the compressor's third-rate frequency reduction high-pressure threshold, and is not less than the compressor's third-rate frequency reduction high-pressure threshold within a first set time in the preset third-rate frequency reduction mode, the compressor is controlled to maintain its current operation, and the process returns to re-control the compressor's current frequency based on the compressor's current high-pressure and its high-pressure range. The specific functions and processing of this control unit 104 are further described in step S720.

[0200] The control unit 104 is further configured to, after controlling the compressor's current frequency to decrease by a preset third rate reduction value at preset third rate reduction intervals, determine whether the compressor's current high-pressure pressure is continuously detected to be less than the compressor's third rate reduction high-pressure pressure threshold within a third set time period in the preset third rate reduction mode. The specific functions and processing of this control unit 104 are further described in step S730. The third set time period in the preset third rate reduction mode is, for example, t in the third rate reduction mode. 连续2 Time. The preset third rate down-frequency time is as follows: t 降频时间 The preset third rate down-frequency value is as follows: ΔF 常速降频 .

[0201] The control unit 104 is further configured to, if it is determined that the current high pressure of the compressor is less than the high pressure threshold of the compressor's third-rate frequency reduction mode within a third set time period continuously during the preset third-rate frequency reduction mode, then, after maintaining the compressor's current frequency under the preset third-rate frequency reduction mode for a fourth time period, control the compressor to exit the preset third-rate frequency reduction mode, thereby exiting the control of the compressor's current frequency reduction according to the preset third-rate frequency reduction mode, and then re-controlling the compressor's current frequency based on the compressor's current high pressure and the compressor's high pressure range. The specific functions and processing of this control unit 104 are further described in step S740. The fourth time period under the preset third-rate frequency reduction mode is, for example, t under the third-rate frequency reduction mode. 连续3 time.

[0202] The control unit 104 is further configured to, if it is determined that the current high-pressure pressure of the compressor is not continuously lower than the high-pressure pressure threshold of the compressor's third-rate frequency reduction mode within a third set time period, and it is determined that the current high-pressure pressure of the compressor is not continuously lower than the high-pressure pressure threshold of the compressor's third-rate frequency reduction mode within a continuous control time period, then control the compressor to stop and control the variable frequency heat pump unit to stop. The specific functions and processing of this control unit 104 are further described in step S750. The continuous control within the preset third-rate frequency reduction mode, such as t... 急速降频持续 .

[0203] like Figure 12 and Figure 13 As shown, the control method for the variable frequency heat pump unit also includes: Step 6, the pressure control method for rapid frequency reduction. Rapid frequency reduction: If the high pressure has exceeded the limit of the compressor block diagram range by a certain amount, to prevent further exceeding the range, the unit immediately increases the frequency reduction amplitude ΔF. 急速降频 ; Compressor rapidly reduces frequency and high pressure P 高压急速降频＝ P 高压保护 -△P4.

[0204] In step 6, after the compressor starts, if t continuously 连续1 Time detected P 高压急速降频 ≤P 高压压力 <P 高压飞速降频 When the condition is met for the first time, the frequency is immediately reduced by ΔF. 急速降频 If the frequency reduction still meets this condition, then F 当前 per t 降频时间 Reduce △F 急速降频 Adjust until continuous t 连续2 Time detected P 高压压力 <P 高压急速降频 Maintain the current frequency F当前 continuous t 连续3 After a certain time, exit the rapid frequency reduction control and determine whether to resume normal control or enter other pressure-limited frequency reduction control based on real-time pressure monitoring. If t continues... 急速降频持续 If the high voltage does not exit the rapid frequency reduction control during the operating period, the unit will be shut down.

[0205] In the solution of this invention, through rapid frequency reduction pressure control, when the high pressure has exceeded the limit of the compressor block diagram range by a certain amount, to prevent further exceeding the range, the unit immediately increases the frequency reduction amplitude ΔF. 急速降频 Allow the pressure to quickly return to the range shown in the compressor diagram. If the high pressure continues to rise for a certain period of time, the unit will shut down.

[0206] In some embodiments, the high-pressure range of the compressor includes a pressure interval defined by a series of increasing parameters: a frequency-limiting high-pressure threshold of the compressor, a block diagram-controlled high-pressure threshold of the compressor, a first-rate frequency-reduction high-pressure threshold of the compressor, a second-rate frequency-reduction high-pressure threshold of the compressor, a third-rate frequency-reduction high-pressure threshold of the compressor, a fourth-rate frequency-reduction high-pressure threshold of the compressor, and a high-pressure protection pressure threshold of the compressor. The control unit 104 controls the current frequency of the compressor based on the current high-pressure and the high-pressure range of the compressor, and further includes a pressure control process under a preset fourth-rate frequency-reduction mode (such as a rapid frequency-reduction mode), as detailed below:

[0207] The control unit 104 is further configured to, after the compressor starts, determine whether, within a first set time period under a preset fourth-rate frequency reduction mode, the current high-pressure pressure of the compressor is detected to be greater than or equal to the high-pressure pressure threshold of the compressor under the fourth-rate frequency reduction mode and less than the high-pressure protection high-pressure threshold of the compressor. The specific functions and processing of this control unit 104 are further described in step S810. The first set time under the preset fourth-rate frequency reduction mode is, for example, t under the fourth-rate frequency reduction mode. 连续1 time.

[0208] The control unit 104 is further configured to, if it is determined that the current high pressure of the compressor is greater than or equal to the high pressure threshold of the compressor's fourth-rate frequency reduction mode and less than the high pressure protection high pressure threshold of the compressor within a first set time period under the preset fourth-rate frequency reduction mode, then control the compressor to enter the preset fourth-rate frequency reduction mode to control the current frequency of the compressor to decrease by the preset fourth-rate frequency reduction value; then, it re-determines whether the current high pressure of the compressor is greater than or equal to the high pressure threshold of the compressor's fourth-rate frequency reduction mode and less than the high pressure protection high pressure threshold of the compressor within the first set time period under the preset fourth-rate frequency reduction mode: if so, control the compressor to enter the preset fourth-rate frequency reduction mode to control the current frequency of the compressor to decrease by the preset fourth-rate frequency reduction value; then, it re-determines whether the current high pressure of the compressor is greater than or equal to the high pressure threshold of the compressor's fourth-rate frequency reduction mode and less than the high pressure protection high pressure threshold of the compressor. The compressor's current frequency is reduced by a preset fourth-rate frequency reduction value every preset fourth-rate frequency reduction time; otherwise, the process returns to re-control the compressor's current frequency based on the compressor's current high-pressure and the compressor's high-pressure range. Of course, if it is determined that the compressor's current high-pressure is not continuously greater than or equal to the compressor's fourth-rate frequency reduction high-pressure threshold and is not less than the compressor's fourth-rate frequency reduction high-pressure threshold within a first set time in the preset fourth-rate frequency reduction mode, then the compressor is controlled to maintain its current operation, and the process returns to re-control the compressor's current frequency based on the compressor's current high-pressure and the compressor's high-pressure range. The specific functions and processing of this control unit 104 are also described in step S820.

[0209] The control unit 104 is further configured to, after controlling the compressor's current frequency to decrease by a preset fourth rate reduction value at preset fourth rate reduction intervals, determine whether the compressor's current high-pressure value is continuously detected to be less than the compressor's fourth rate reduction high-pressure pressure threshold within a fourth time interval of the preset fourth rate reduction mode. The specific functions and processing of this control unit 104 are further described in step S830. The fourth time interval of the preset fourth rate reduction mode is, for example, t within the fourth rate reduction mode. 连续2 Time. The preset fourth rate down-frequency time is as follows: t 降频时间 The preset fourth rate reduction value is ΔF constant rate reduction.

[0210] The control unit 104 is further configured to, if it is determined that the current high pressure of the compressor is less than the high pressure threshold of the compressor's fourth-rate frequency reduction mode within a fourth time period continuously during the preset fourth-rate frequency reduction mode, then, after maintaining the compressor's current frequency under the preset fourth-rate frequency reduction mode for the fourth time period, control the compressor to exit the preset fourth-rate frequency reduction mode, thereby exiting the control of the compressor's current frequency reduction according to the preset fourth-rate frequency reduction mode, and then re-controlling the compressor's current frequency based on the compressor's current high pressure and the compressor's high pressure range. The specific functions and processing of this control unit 104 are further described in step S840. The fourth time period under the preset fourth-rate frequency reduction mode is, for example, t in the fourth-rate frequency reduction mode. 连续3 time.

[0211] The control unit 104 is further configured to, if it is determined that the current high-pressure pressure of the compressor is not continuously lower than the high-pressure pressure threshold of the compressor's fourth-rate frequency reduction mode within a fourth time period, and it is determined that the current high-pressure pressure of the compressor is not continuously lower than the high-pressure pressure threshold of the compressor's fourth-rate frequency reduction mode within a continuous control time period, then control the compressor to stop and control the variable frequency heat pump unit to stop. The specific functions and processing of this control unit 104 are further described in step S850. The continuous control within the preset fourth-rate frequency reduction mode, such as t... 飞速降频持续 .

[0212] like Figure 12 and Figure 13 As shown, the control method for the variable frequency heat pump unit also includes: Step 7, the pressure control method for rapid frequency reduction. Rapid frequency reduction: When the high pressure is about to reach the high pressure protection value, it is necessary to quickly reduce ΔF. 飞速降频 The compressor rapidly reduces its frequency and applies high-pressure P. 高压飞速降频＝ P 高压保护 -△P5.

[0213] In step 7, after the compressor starts, if t continuously 连续1 Time detected P 高压飞速降频 ≤P 高压压力 <P 高压保护 When the condition is met for the first time, the frequency is immediately reduced by ΔF. 飞速降频 If the frequency reduction still meets this condition, then F 当前 per t 降频时间 Reduce △F 飞速降频 Adjust until continuous t 连续2 Time detected P 高压压力 <P 高压飞速降频 Maintain the current frequency F 当前 continuous t 连续3After a certain time, exit the rapid frequency reduction control and determine whether to resume normal control or enter other pressure-limited frequency reduction control based on real-time pressure monitoring. If t continues... 飞速降频持续 If the high voltage does not exit the rapid frequency reduction control during the operating period, the unit will be shut down.

[0214] The relationship between the frequency reduction amplitude and the frequency reduction amplitude is ΔF. 常速降频 <△F 超框图降频 <△F 快速降频 <△F 急速降频 <△F 飞速降频 For example: △F 常速降频 (2Hz)<△F 超框图降频 (4Hz)<△F 快速降频 (8Hz)<△F 急速降频 (10Hz)<△F 飞速降频 (12Hz).

[0215] The continuous runtime downtime relationship is t 压缩机框图持续 >t 快速降频持续 >t 急速降频持续 >t 飞速降频持续 For example: t 压缩机框图持续 (30min)>t 快速降频持续 (15min)>t 急速降频持续 (5min)>t 飞速降频持续 (3min).

[0216] In the solution of this invention, through rapid frequency reduction pressure control, when the high pressure is about to reach the high pressure protection value, it is necessary to quickly reduce ΔF. 飞速降频 See if the high pressure can be released. If the high pressure continues to rise for a certain period of time, the unit should be shut down.

[0217] In some embodiments, the high-pressure range of the compressor includes: a pressure interval divided by a series of increasing high-pressure thresholds: a frequency-limited high-pressure threshold, a block diagram controlled high-pressure threshold, a first-rate frequency-reduced high-pressure threshold, a second-rate frequency-reduced high-pressure threshold, a third-rate frequency-reduced high-pressure threshold, a fourth-rate frequency-reduced high-pressure threshold, and a high-pressure protection threshold. The control unit 104 controls the current frequency of the compressor based on its current high-pressure and the high-pressure range, and further includes a pressure control process under a preset high-pressure protection mode, as detailed below:

[0218] The control unit 104 is further configured to, after the compressor starts, determine whether, within a preset first set time period under a high-pressure protection mode, the current high-pressure pressure of the compressor is continuously detected to be greater than or equal to the high-pressure protection high-pressure threshold of the compressor. The specific functions and processing of this control unit 104 are further described in step S910. The preset first set time under the fourth rate reduction mode is, for example, t in the fourth rate reduction mode. 连续1 time.

[0219] The control unit 104 is further configured to, if it is determined that the current high pressure of the compressor is continuously greater than or equal to the high pressure protection threshold of the compressor within a first set time in the preset high pressure protection mode, then control the high pressure switch of the variable frequency heat pump unit to open and control the variable frequency heat pump unit to stop; of course, if it is determined that the current high pressure of the compressor is not continuously greater than or equal to the high pressure protection threshold of the compressor within the first set time in the preset high pressure protection mode, then control the compressor to maintain its current operation and return to re-control the current frequency of the compressor based on the current high pressure of the compressor and the high pressure range of the compressor. The specific functions and processing of this control unit 104 are also described in step S920.

[0220] like Figure 12 and Figure 13 As shown, the control method for the variable frequency heat pump unit also includes: step 8, pressure control method for high-pressure protection. High-pressure protection: If the high-pressure exceeds the protection value of the high-pressure switch, the unit will shut down due to a fault; the compressor high-pressure protection high-pressure P 高压保护 .

[0221] In step 8, after the compressor starts, if t continuously 连续1 Time detected P 高压压力 ≥P 高压保护 If the high-voltage switch is disconnected, the unit will shut down.

[0222] In the solution of this invention, the unit malfunctions and shuts down when the high pressure exceeds the protection value of the high pressure switch through pressure control of high pressure protection.

[0223] This invention proposes a seven-fold pressure control method, comprising frequency limiting, constant-speed frequency reduction, super-compressor block diagram, rapid frequency reduction, swift frequency reduction, high-speed frequency reduction, and high-pressure protection. Different frequency reduction amplitudes and dwell times are used for each defined pressure range to control the high pressure within a reasonable range. This solves the problem of excessive high pressure due to over-regulation of the electronic expansion valve or compressor frequency, avoids frequent over-pressure operation and high-pressure protection of the unit, and ensures stable and reliable operation of the unit.

[0224] Since the processing and functions implemented by the device in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0225] According to an embodiment of the present invention, a variable frequency heat pump unit corresponding to a control device for a variable frequency heat pump unit is also provided. This variable frequency heat pump unit may include the control device for the variable frequency heat pump unit described above.

[0226] Since the processing and functions implemented by the variable frequency heat pump unit in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned device, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0227] According to an embodiment of the present invention, a computer program product corresponding to a variable frequency heat pump unit is also provided, including a computer program that, when executed by a processor, implements the steps of the control method for the variable frequency heat pump unit described above.

[0228] Since the processing and functions implemented by the product in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned variable frequency heat pump units, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0229] According to an embodiment of the present invention, a storage medium corresponding to a control method for a variable frequency heat pump unit is also provided. The storage medium includes a stored program, wherein, when the program is executed, the device where the storage medium is located is controlled to perform the steps of the control method for the variable frequency heat pump unit described above.

[0230] Since the processing and functions implemented by the storage medium in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0231] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous methods can be freely combined and superimposed.

[0232] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A control method of a variable frequency heat pump unit, characterized by, The variable frequency heat pump unit has a compressor; the control method of the variable frequency heat pump unit comprises: obtaining the frame control high pressure threshold of the compressor, and obtaining the high pressure protection threshold of the compressor; the frame control high pressure threshold of the compressor is set in advance according to the performance of the compressor; determining the high pressure range of the compressor according to the frame control high pressure threshold of the compressor and the high pressure protection threshold of the compressor; after the variable frequency heat pump unit is powered on, obtaining the current high pressure of the compressor after the compressor is started, and obtaining the current frequency of the compressor; controlling the current frequency of the compressor according to the current high pressure of the compressor and the high pressure range of the compressor, so as to adjust the current high pressure of the compressor to be within the high pressure range of the compressor, comprising: determining the difference between the frame control high pressure threshold of the compressor and the preset first pressure threshold as the frequency limiting high pressure threshold of the compressor; determining the difference between the frame control high pressure threshold of the compressor and the preset second pressure threshold as the first rate frequency reduction high pressure threshold of the compressor; determining the sum of the frame control high pressure threshold of the compressor and the preset third pressure threshold as the second rate frequency reduction high pressure threshold of the compressor; determining the difference between the high pressure protection threshold of the compressor and the preset fourth pressure threshold as the third rate frequency reduction high pressure threshold of the compressor; determining the difference between the high pressure protection threshold of the compressor and the preset fifth pressure threshold as the fourth rate frequency reduction high pressure threshold of the compressor; determining the high pressure range of the compressor according to the frequency limiting high pressure threshold of the compressor, the frame control high pressure threshold of the compressor, the first rate frequency reduction high pressure threshold of the compressor, the second rate frequency reduction high pressure threshold of the compressor, the third rate frequency reduction high pressure threshold of the compressor, the fourth rate frequency reduction high pressure threshold of the compressor and the high pressure protection threshold of the compressor.

2. The control method of a variable frequency heat pump unit according to claim 1, characterized by, The high pressure range of the compressor comprises: the pressure interval divided by the frequency limiting high pressure threshold of the compressor, the frame control high pressure threshold of the compressor, the first rate frequency reduction high pressure threshold of the compressor, the second rate frequency reduction high pressure threshold of the compressor, the third rate frequency reduction high pressure threshold of the compressor, the fourth rate frequency reduction high pressure threshold of the compressor and the high pressure protection threshold of the compressor in turn; controlling the current frequency of the compressor according to the current high pressure of the compressor and the high pressure range of the compressor, comprising: determining whether the current high pressure of the compressor is greater than or equal to the frequency limiting high pressure threshold of the compressor and less than the first rate frequency reduction high pressure threshold of the compressor within the first set time in the preset frequency limiting mode in succession; If it is determined that the current high pressure of the compressor is greater than or equal to the high pressure threshold of the compressor in the preset frequency limiting mode for a first set time, the current frequency of the compressor is controlled to be increased to the first speed of the compressor; and then it is determined whether the current high pressure of the compressor is less than the high pressure threshold of the compressor in the preset frequency limiting mode for a second set time. If it is determined that the current high pressure of the compressor is less than the high pressure threshold of the compressor in the preset frequency limiting mode for the second set time, the current frequency of the compressor is controlled to be increased to the first speed of the compressor after a third set time in the preset frequency limiting mode; and then the current frequency of the compressor is controlled to be increased to the second speed of the compressor. If it is determined that the current high pressure of the compressor is not less than the high pressure threshold of the compressor in the preset frequency limiting mode for the second set time, the current frequency of the compressor is controlled according to the current high pressure of the compressor and the high pressure range of the compressor.

3. The control method of a variable frequency heat pump unit according to claim 1 or 2, characterized by, The high pressure range of the compressor comprises pressure intervals divided by the high pressure threshold of the compressor, the chart control high pressure threshold of the compressor, the first speed frequency reduction high pressure threshold of the compressor, the second speed frequency reduction high pressure threshold of the compressor, the third speed frequency reduction high pressure threshold of the compressor, the fourth speed frequency reduction high pressure threshold of the compressor and the high pressure protection threshold of the compressor. The method for controlling the current frequency of the compressor according to the current high pressure of the compressor and the high pressure range of the compressor further comprises: determining whether the current high pressure of the compressor is greater than or equal to the first speed frequency reduction high pressure threshold of the compressor and less than the chart control high pressure threshold of the compressor in the preset first speed frequency reduction mode for a first set time. If it is determined that the current high pressure of the compressor is greater than or equal to the first rate reduction high pressure threshold of the compressor and less than the chart control high pressure threshold of the compressor for a first set time continuously in the preset first rate reduction mode, the compressor is controlled to enter the preset first rate reduction mode to control the current frequency of the compressor to reduce by a preset first rate reduction value; then it is determined again whether the current high pressure of the compressor is greater than or equal to the first rate reduction high pressure threshold of the compressor and less than the chart control high pressure threshold of the compressor for a first set time continuously in the preset first rate reduction mode; if yes, the current frequency of the compressor is controlled to reduce by a preset first rate reduction value every preset first rate reduction time; otherwise, the current frequency of the compressor is controlled again according to the current high pressure of the compressor and the high pressure range of the compressor; After the current frequency of the compressor is controlled to reduce by a preset first rate reduction value every preset first rate reduction time, it is determined whether the current high pressure of the compressor is less than the first rate reduction high pressure threshold of the compressor for a second set time continuously in the preset first rate reduction mode; If it is determined that the current high pressure of the compressor is less than the first rate reduction high pressure threshold of the compressor for a second set time continuously in the preset first rate reduction mode, the current frequency of the compressor is maintained for a third set time in the preset first rate reduction mode, and then the compressor is controlled to exit the preset first rate reduction mode to exit the control of the current frequency of the compressor to reduce in the preset first rate reduction mode, and then the current frequency of the compressor is controlled again according to the current high pressure of the compressor and the high pressure range of the compressor; If it is determined that the current high pressure of the compressor is not less than the first rate reduction high pressure threshold of the compressor for a second set time continuously in the preset first rate reduction mode, the current frequency of the compressor is controlled again according to the current high pressure of the compressor and the high pressure range of the compressor.

4. The control method of a variable frequency heat pump unit according to claim 1 or 2, characterized by, The high pressure range of the compressor includes pressure intervals divided by the limit frequency high pressure threshold of the compressor, the chart control high pressure threshold of the compressor, the first rate reduction high pressure threshold of the compressor, the second rate reduction high pressure threshold of the compressor, the third rate reduction high pressure threshold of the compressor, the fourth rate reduction high pressure threshold of the compressor, and the high pressure protection threshold of the compressor in sequence; The control of the current frequency of the compressor according to the current high pressure of the compressor and the high pressure range of the compressor further includes: determining whether the current high-pressure pressure of the compressor is greater than or equal to the high-pressure pressure threshold of the compressor and less than the second rate reduction high-pressure pressure threshold of the compressor continuously for a first preset time in the preset block diagram control mode; if it is determined that the current high-pressure pressure of the compressor is greater than or equal to the high-pressure pressure threshold of the compressor and less than the second rate reduction high-pressure pressure threshold of the compressor continuously for the first preset time in the preset block diagram control mode, controlling the compressor to enter the preset block diagram control mode to control the current frequency of the compressor to be reduced by a preset block diagram control reduction value, and then redetermining whether the current high-pressure pressure of the compressor is greater than or equal to the high-pressure pressure threshold of the compressor and less than the second rate reduction high-pressure pressure threshold of the compressor continuously for the first preset time in the preset block diagram control mode; if yes, controlling the current frequency of the compressor to be reduced by the preset block diagram control reduction value every preset block diagram control time; otherwise, returning to control the current frequency of the compressor according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor; after controlling the current frequency of the compressor to be reduced by the preset block diagram control reduction value every preset block diagram control time, determining whether the current high-pressure pressure of the compressor is less than the high-pressure pressure threshold of the compressor continuously for a second preset time in the preset block diagram control mode; if it is determined that the current high-pressure pressure of the compressor is less than the high-pressure pressure threshold of the compressor continuously for the second preset time in the preset block diagram control mode, maintaining the current frequency of the compressor for a third preset time in the preset block diagram control mode, and then controlling the compressor to exit the preset block diagram control mode to exit the frequency reduction of the current frequency of the compressor in the preset block diagram control mode, and then controlling the current frequency of the compressor according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor; if it is determined that the current high-pressure pressure of the compressor is not less than the high-pressure pressure threshold of the compressor continuously for the second preset time in the preset block diagram control mode, and it is determined that the current high-pressure pressure of the compressor is not less than the high-pressure pressure threshold of the compressor continuously for a continuous control time in the preset block diagram control mode, controlling the compressor to stop and controlling the variable frequency heat pump unit to stop.

5. The control method of a variable frequency heat pump unit according to claim 3, wherein, the high-pressure pressure range of the compressor includes pressure intervals divided by the frequency limiting high-pressure pressure threshold of the compressor, the high-pressure pressure threshold of the compressor, the first rate reduction high-pressure pressure threshold of the compressor, the second rate reduction high-pressure pressure threshold of the compressor, the third rate reduction high-pressure pressure threshold of the compressor, the fourth rate reduction high-pressure pressure threshold of the compressor, and the high-pressure protection pressure threshold of the compressor. The method for controlling the current frequency of the compressor according to the current high-pressure of the compressor and the high-pressure range of the compressor further comprises: determining whether the current high-pressure of the compressor is greater than or equal to the high-pressure threshold of the compressor in the frame control mode and less than the second speed reduction high-pressure threshold of the compressor for a first set time in the frame control mode; if it is determined that the current high-pressure of the compressor is greater than or equal to the high-pressure threshold of the compressor in the frame control mode and less than the second speed reduction high-pressure threshold of the compressor for a first set time in the frame control mode, controlling the compressor to enter the frame control mode to reduce the current frequency of the compressor by a frame control reduction value at every frame control time, and then re-determining whether the current high-pressure of the compressor is greater than or equal to the high-pressure threshold of the compressor in the frame control mode and less than the second speed reduction high-pressure threshold of the compressor for a first set time in the frame control mode; if yes, controlling the current frequency of the compressor to reduce by the frame control reduction value at every frame control time; otherwise, returning to control the current frequency of the compressor according to the current high-pressure of the compressor and the high-pressure range of the compressor; after controlling the current frequency of the compressor to reduce by the frame control reduction value at every frame control time, determining whether the current high-pressure of the compressor is less than the high-pressure threshold of the compressor for a second set time in the frame control mode; if it is determined that the current high-pressure of the compressor is less than the high-pressure threshold of the compressor for a second set time in the frame control mode, maintaining the current frequency of the compressor for a third set time in the frame control mode, and then controlling the compressor to exit the frame control mode to exit the frequency reduction of the current frequency of the compressor in the frame control mode, and then controlling the current frequency of the compressor according to the current high-pressure of the compressor and the high-pressure range of the compressor; if it is determined that the current high-pressure of the compressor is not less than the high-pressure threshold of the compressor for a second set time in the frame control mode, and it is determined that the current high-pressure of the compressor is not less than the high-pressure threshold of the compressor for a continuous control time in the frame control mode, controlling the compressor to stop and controlling the variable frequency heat pump unit to stop.

6. The control method of the variable frequency heat pump unit according to any one of claims 1, 2, 5, characterized by, The high pressure range of the compressor comprises: a pressure interval divided by a frequency limiting high pressure threshold of the compressor, a block diagram control high pressure threshold of the compressor, a first rate reduction high pressure threshold of the compressor, a second rate reduction high pressure threshold of the compressor, a third rate reduction high pressure threshold of the compressor, a fourth rate reduction high pressure threshold of the compressor, and a high pressure protection threshold of the compressor; Wherein, According to the current high pressure of the compressor and the high pressure range of the compressor, the current frequency of the compressor is controlled, and the method further comprises: determining whether the current high pressure of the compressor greater than or equal to the second rate reduction high pressure threshold of the compressor and less than the third rate reduction high pressure threshold of the compressor is detected continuously within a first set time in the preset second rate reduction mode; If it is determined that the current high pressure of the compressor greater than or equal to the second rate reduction high pressure threshold of the compressor and less than the third rate reduction high pressure threshold of the compressor is detected continuously within a first set time in the preset second rate reduction mode, the compressor is controlled to enter the preset second rate reduction mode to control the current frequency of the compressor to reduce by a preset second rate reduction value, and then it is determined again whether the current high pressure of the compressor greater than or equal to the second rate reduction high pressure threshold of the compressor and less than the third rate reduction high pressure threshold of the compressor is detected continuously within a first set time in the preset second rate reduction mode: if yes, the current frequency of the compressor is controlled to reduce by a preset second rate reduction value every preset second rate reduction time; otherwise, the current frequency of the compressor is controlled again according to the current high pressure of the compressor and the high pressure range of the compressor; After the current frequency of the compressor is controlled to reduce by a preset second rate reduction value every preset second rate reduction time, it is determined whether the current high pressure of the compressor less than the second rate reduction high pressure threshold of the compressor is detected continuously within a second set time in the preset second rate reduction mode; If it is determined that the current high pressure of the compressor less than the second rate reduction high pressure threshold of the compressor is detected continuously within a second set time in the preset second rate reduction mode, the current frequency of the compressor is maintained for a third set time in the preset second rate reduction mode, and then the compressor is controlled to exit the preset second rate reduction mode to exit the control of the current frequency of the compressor to reduce by a preset second rate reduction value in the preset second rate reduction mode, and then the current frequency of the compressor is controlled again according to the current high pressure of the compressor and the high pressure range of the compressor; If it is determined that the current high-pressure pressure of the compressor is less than the second rate reduction high-pressure pressure threshold of the compressor is not detected for a second set time in the preset second rate reduction mode continuously, and it is determined that the current high-pressure pressure of the compressor is less than the second rate reduction high-pressure pressure threshold of the compressor is not detected for a continuous control time in the preset second rate reduction mode, the compressor is controlled to stop, and the variable frequency heat pump unit is controlled to stop; and / or, According to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor, the current frequency of the compressor is controlled, and the method further comprises: determining whether the current high-pressure pressure of the compressor is greater than or equal to the third rate reduction high-pressure pressure threshold of the compressor and less than the fourth rate reduction high-pressure pressure threshold of the compressor is detected for a first set time in the preset third rate reduction mode continuously; If it is determined that the current high-pressure pressure of the compressor is greater than or equal to the third rate reduction high-pressure pressure threshold of the compressor and less than the fourth rate reduction high-pressure pressure threshold of the compressor is detected for a first set time in the preset third rate reduction mode continuously, the compressor is controlled to enter the preset third rate reduction mode to control the current frequency of the compressor to reduce by a preset third rate reduction value, and then it is determined again whether the current high-pressure pressure of the compressor is greater than or equal to the third rate reduction high-pressure pressure threshold of the compressor and less than the fourth rate reduction high-pressure pressure threshold of the compressor is detected for a first set time in the preset third rate reduction mode continuously: if yes, the current frequency of the compressor is controlled to reduce by a preset third rate reduction value every preset third rate reduction time; otherwise, the current frequency of the compressor is controlled again according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor; After the current frequency of the compressor is controlled to reduce by a preset third rate reduction value every preset third rate reduction time, it is determined whether the current high-pressure pressure of the compressor is less than the third rate reduction high-pressure pressure threshold of the compressor is detected for a third set time in the preset third rate reduction mode continuously; If it is determined that the current high-pressure pressure of the compressor is less than the third rate reduction high-pressure pressure threshold of the compressor is detected for a third set time in the preset third rate reduction mode continuously, the current frequency of the compressor is maintained for a fourth time in the preset third rate reduction mode, and then the compressor is controlled to exit the preset third rate reduction mode to exit the control of the current frequency of the compressor to reduce in the preset third rate reduction mode, and then the current frequency of the compressor is controlled again according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor; If it is determined that the current high-pressure pressure of the compressor is less than the third rate reduction high-pressure pressure threshold of the compressor is not detected continuously for the third set time in the preset third rate reduction mode, and it is determined that the current high-pressure pressure of the compressor is less than the third rate reduction high-pressure pressure threshold of the compressor is not detected continuously for the continuous control time in the preset third rate reduction mode, the compressor is controlled to stop, and the variable frequency heat pump unit is controlled to stop; and / or, According to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor, the current frequency of the compressor is controlled, and the method further comprises: determining whether the current high-pressure pressure of the compressor is greater than or equal to the fourth rate reduction high-pressure pressure threshold of the compressor and less than the high-pressure protection high-pressure pressure threshold of the compressor is detected continuously for the first set time in the preset fourth rate reduction mode; If it is determined that the current high-pressure pressure of the compressor is greater than or equal to the fourth rate reduction high-pressure pressure threshold of the compressor and less than the high-pressure protection high-pressure pressure threshold of the compressor is detected continuously for the first set time in the preset fourth rate reduction mode, the compressor is controlled to enter the preset fourth rate reduction mode to control the current frequency of the compressor to reduce the preset fourth rate reduction value, and then it is determined again whether the current high-pressure pressure of the compressor is greater than or equal to the fourth rate reduction high-pressure pressure threshold of the compressor and less than the high-pressure protection high-pressure pressure threshold of the compressor is detected continuously for the first set time in the preset fourth rate reduction mode: if yes, the current frequency of the compressor is controlled to reduce the preset fourth rate reduction value every preset fourth rate reduction time; otherwise, the current frequency of the compressor is controlled again according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor; After the current frequency of the compressor is controlled to reduce the preset fourth rate reduction value every preset fourth rate reduction time, it is determined whether the current high-pressure pressure of the compressor is less than the fourth rate reduction high-pressure pressure threshold of the compressor is detected continuously for the fourth time in the preset fourth rate reduction mode; If it is determined that the current high-pressure pressure of the compressor is less than the fourth rate reduction high-pressure pressure threshold of the compressor is detected continuously for the fourth time in the preset fourth rate reduction mode, the current frequency of the compressor is maintained for the fourth time in the preset fourth rate reduction mode, and then the compressor is controlled to exit the preset fourth rate reduction mode to exit the control of the current frequency of the compressor to reduce the frequency in the preset fourth rate reduction mode, and then the current frequency of the compressor is controlled again according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor; If it is determined that the current high-pressure pressure of the compressor is less than the fourth rate reduction high-pressure pressure threshold of the compressor for a fourth time continuously in the preset fourth rate reduction mode, and it is determined that the current high-pressure pressure of the compressor is less than the fourth rate reduction high-pressure pressure threshold of the compressor for a continuous control time continuously in the preset fourth rate reduction mode, the compressor is controlled to stop, and the variable frequency heat pump unit is controlled to stop; and / or, According to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor, the current frequency of the compressor is controlled, and the method further comprises: determining whether the current high-pressure pressure of the compressor is greater than or equal to the high-pressure protection high-pressure pressure threshold of the compressor for a first set time continuously in the preset high-pressure protection mode; If it is determined that the current high-pressure pressure of the compressor is greater than or equal to the high-pressure protection high-pressure pressure threshold of the compressor for a first set time continuously in the preset high-pressure protection mode, the high-pressure switch of the variable frequency heat pump unit is controlled to be turned off, and the variable frequency heat pump unit is controlled to stop.

7. The control method of a variable frequency heat pump unit according to claim 3, wherein The high-pressure pressure range of the compressor comprises a pressure interval divided by the frequency limiting high-pressure pressure threshold of the compressor, the block diagram control high-pressure pressure threshold of the compressor, the first rate reduction high-pressure pressure threshold of the compressor, the second rate reduction high-pressure pressure threshold of the compressor, the third rate reduction high-pressure pressure threshold of the compressor, the fourth rate reduction high-pressure pressure threshold of the compressor, and the high-pressure protection pressure threshold of the compressor in sequence. According to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor, the current frequency of the compressor is controlled, and the method further comprises: determining whether the current high-pressure pressure of the compressor is greater than or equal to the second rate reduction high-pressure pressure threshold of the compressor and less than the third rate reduction high-pressure pressure threshold of the compressor for a first set time continuously in the preset second rate reduction mode; If it is determined that the current high-pressure pressure of the compressor is greater than or equal to the second rate reduction high-pressure pressure threshold of the compressor and less than the third rate reduction high-pressure pressure threshold of the compressor for a first set time continuously in the preset second rate reduction mode, the compressor is controlled to enter the preset second rate reduction mode to control the current frequency of the compressor to be reduced by a preset second rate reduction value; and then it is determined again whether the current high-pressure pressure of the compressor is greater than or equal to the second rate reduction high-pressure pressure threshold of the compressor and less than the third rate reduction high-pressure pressure threshold of the compressor for a first set time continuously in the preset second rate reduction mode: if yes, the current frequency of the compressor is controlled to be reduced by the preset second rate reduction value every preset second rate reduction time; otherwise, the current frequency of the compressor is controlled again according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor. ​ determining whether the current high-pressure pressure of the compressor is less than the second rate reduction high-pressure pressure threshold of the compressor continuously for a second set time in the preset second rate reduction mode; if it is determined that the current high-pressure pressure of the compressor is less than the second rate reduction high-pressure pressure threshold of the compressor continuously for the second set time in the preset second rate reduction mode, maintaining the current frequency of the compressor for a third set time in the preset second rate reduction mode, and then controlling the compressor to exit the preset second rate reduction mode to exit the frequency reduction of the current frequency of the compressor in the preset second rate reduction mode, and then controlling the current frequency of the compressor according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor again; if it is determined that the current high-pressure pressure of the compressor is not less than the second rate reduction high-pressure pressure threshold of the compressor continuously for the second set time in the preset second rate reduction mode, and it is determined that the current high-pressure pressure of the compressor is not less than the second rate reduction high-pressure pressure threshold of the compressor continuously for a continuous control time in the preset second rate reduction mode, controlling the compressor to shut down, and controlling the variable frequency heat pump unit to shut down; and / or, controlling the current frequency of the compressor according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor, further comprising: determining whether the current high-pressure pressure of the compressor is greater than or equal to the third rate reduction high-pressure pressure threshold of the compressor and less than the fourth rate reduction high-pressure pressure threshold of the compressor continuously for a first set time in the preset third rate reduction mode; if it is determined that the current high-pressure pressure of the compressor is greater than or equal to the third rate reduction high-pressure pressure threshold of the compressor and less than the fourth rate reduction high-pressure pressure threshold of the compressor continuously for the first set time in the preset third rate reduction mode, controlling the compressor to enter the preset third rate reduction mode to control the current frequency of the compressor to reduce by a preset third rate reduction value, and then determining again whether the current high-pressure pressure of the compressor is greater than or equal to the third rate reduction high-pressure pressure threshold of the compressor and less than the fourth rate reduction high-pressure pressure threshold of the compressor continuously for the first set time in the preset third rate reduction mode; if yes, controlling the current frequency of the compressor to reduce by the preset third rate reduction value every preset third rate reduction time; otherwise, returning to control the current frequency of the compressor according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor again. determining whether the current high-pressure pressure of the compressor is less than the third rate reduction high-pressure pressure threshold of the compressor continuously for a third set time in the third rate reduction mode; if it is determined that the current high-pressure pressure of the compressor is less than the third rate reduction high-pressure pressure threshold of the compressor continuously for the third set time in the third rate reduction mode, maintaining the current frequency of the compressor for a fourth time in the third rate reduction mode, and then controlling the compressor to exit the third rate reduction mode, to exit the frequency reduction of the current frequency of the compressor in the third rate reduction mode, and then controlling the current frequency of the compressor according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor again; if it is determined that the current high-pressure pressure of the compressor is not less than the third rate reduction high-pressure pressure threshold of the compressor continuously for the third set time in the third rate reduction mode, and it is determined that the current high-pressure pressure of the compressor is not less than the third rate reduction high-pressure pressure threshold of the compressor continuously for a continuous control time in the third rate reduction mode, controlling the compressor to stop, and controlling the variable frequency heat pump unit to stop; and / or, controlling the current frequency of the compressor according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor, further comprising: determining whether the current high-pressure pressure of the compressor is greater than or equal to the fourth rate reduction high-pressure pressure threshold of the compressor and less than the high-pressure protection high-pressure pressure threshold of the compressor continuously for a first set time in the fourth rate reduction mode; if it is determined that the current high-pressure pressure of the compressor is greater than or equal to the fourth rate reduction high-pressure pressure threshold of the compressor and less than the high-pressure protection high-pressure pressure threshold of the compressor continuously for the first set time in the fourth rate reduction mode, controlling the compressor to enter the fourth rate reduction mode, to control the current frequency of the compressor to reduce by a fourth rate reduction value every fourth rate reduction time; and then determining again whether the current high-pressure pressure of the compressor is greater than or equal to the fourth rate reduction high-pressure pressure threshold of the compressor and less than the high-pressure protection high-pressure pressure threshold of the compressor continuously for the first set time in the fourth rate reduction mode: if yes, controlling the current frequency of the compressor to reduce by the fourth rate reduction value every fourth rate reduction time; otherwise, returning to control the current frequency of the compressor according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor again; determining whether the current high-pressure pressure of the compressor is less than the fourth rate reduction high-pressure pressure threshold of the compressor continuously for a fourth time in the preset fourth rate reduction mode; if it is determined that the current high-pressure pressure of the compressor is less than the fourth rate reduction high-pressure pressure threshold of the compressor continuously for the fourth time in the preset fourth rate reduction mode, maintaining the current frequency of the compressor for the fourth time in the preset fourth rate reduction mode, and then controlling the compressor to exit the preset fourth rate reduction mode to exit the frequency reduction of the current frequency of the compressor in the preset fourth rate reduction mode, and then controlling the current frequency of the compressor according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor; if it is determined that the current high-pressure pressure of the compressor is less than the fourth rate reduction high-pressure pressure threshold of the compressor continuously for the fourth time in the preset fourth rate reduction mode, and it is determined that the current high-pressure pressure of the compressor is less than the fourth rate reduction high-pressure pressure threshold of the compressor continuously for a continuous control time in the preset fourth rate reduction mode, controlling the compressor to shut down, and controlling the variable frequency heat pump unit to shut down; and / or, controlling the current frequency of the compressor according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor, further comprising: determining whether the current high-pressure pressure of the compressor is greater than or equal to the high-pressure protection high-pressure pressure threshold of the compressor continuously for a first set time in the preset high-pressure protection mode; if it is determined that the current high-pressure pressure of the compressor is greater than or equal to the high-pressure protection high-pressure pressure threshold of the compressor continuously for the first set time in the preset high-pressure protection mode, controlling the high-pressure switch of the variable frequency heat pump unit to be turned off, and controlling the variable frequency heat pump unit to shut down.

8. The control method of a variable frequency heat pump unit according to claim 4, characterized by, the high-pressure pressure range of the compressor includes pressure intervals divided by the frequency limiting high-pressure pressure threshold of the compressor, the block diagram control high-pressure pressure threshold of the compressor, the first rate reduction high-pressure pressure threshold of the compressor, the second rate reduction high-pressure pressure threshold of the compressor, the third rate reduction high-pressure pressure threshold of the compressor, the fourth rate reduction high-pressure pressure threshold of the compressor, and the high-pressure protection pressure threshold of the compressor; wherein, controlling the current frequency of the compressor according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor, further comprising: determining whether the current high-pressure pressure of the compressor is greater than or equal to the second rate reduction high-pressure pressure threshold of the compressor and less than the third rate reduction high-pressure pressure threshold of the compressor continuously for a first set time in the preset second rate reduction mode; If it is determined that the current high-pressure pressure of the compressor is greater than or equal to the second rate reduction high-pressure pressure threshold of the compressor and less than the third rate reduction high-pressure pressure threshold of the compressor for a first set time in the preset second rate reduction mode, the compressor is controlled to enter the preset second rate reduction mode to control the current frequency of the compressor to reduce by a preset second rate reduction value; then it is determined again whether the current high-pressure pressure of the compressor is greater than or equal to the second rate reduction high-pressure pressure threshold of the compressor and less than the third rate reduction high-pressure pressure threshold of the compressor for a first set time in the preset second rate reduction mode; if yes, the current frequency of the compressor is controlled to reduce by a preset second rate reduction value every preset second rate reduction time; otherwise, the current frequency of the compressor is controlled again according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor; After the current frequency of the compressor is controlled to reduce by a preset second rate reduction value every preset second rate reduction time, it is determined whether the current high-pressure pressure of the compressor is less than the second rate reduction high-pressure pressure threshold of the compressor for a second set time in the preset second rate reduction mode; If it is determined that the current high-pressure pressure of the compressor is less than the second rate reduction high-pressure pressure threshold of the compressor for a second set time in the preset second rate reduction mode, the current frequency of the compressor is maintained for a third set time in the preset second rate reduction mode, and then the compressor is controlled to exit the preset second rate reduction mode to exit the control of the current frequency of the compressor to reduce in the preset second rate reduction mode; then the current frequency of the compressor is controlled again according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor; If it is determined that the current high-pressure pressure of the compressor is not less than the second rate reduction high-pressure pressure threshold of the compressor for a second set time in the preset second rate reduction mode, and it is determined that the current high-pressure pressure of the compressor is not less than the second rate reduction high-pressure pressure threshold of the compressor for a continuous control time in the preset second rate reduction mode, the compressor is controlled to stop, and the variable frequency heat pump unit is controlled to stop; and / or, The control of the current frequency of the compressor according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor further includes: It is determined whether the current high-pressure pressure of the compressor is greater than or equal to the third rate reduction high-pressure pressure threshold of the compressor and less than the fourth rate reduction high-pressure pressure threshold of the compressor for a first set time in the preset third rate reduction mode; If it is determined that the current high-pressure pressure of the compressor is greater than or equal to the third rate reduction high-pressure pressure threshold of the compressor and less than the fourth rate reduction high-pressure pressure threshold of the compressor for a first set time in the third rate reduction mode, the current frequency of the compressor is controlled to reduce by a third rate reduction value at a third rate reduction time interval in the third rate reduction mode; and then it is determined again whether the current high-pressure pressure of the compressor is greater than or equal to the third rate reduction high-pressure pressure threshold of the compressor and less than the fourth rate reduction high-pressure pressure threshold of the compressor for the first set time in the third rate reduction mode: if yes, the current frequency of the compressor is controlled to reduce by the third rate reduction value at the third rate reduction time interval; and if no, the current frequency of the compressor is controlled again according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor. After the current frequency of the compressor is controlled to reduce by the third rate reduction value at the third rate reduction time interval, it is determined whether the current high-pressure pressure of the compressor is less than the third rate reduction high-pressure pressure threshold of the compressor for a third set time in the third rate reduction mode. If it is determined that the current high-pressure pressure of the compressor is less than the third rate reduction high-pressure pressure threshold of the compressor for the third set time in the third rate reduction mode, the current frequency of the compressor is maintained for a fourth time in the third rate reduction mode, and then the current frequency of the compressor is controlled to exit the third rate reduction mode, and then the current frequency of the compressor is controlled again according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor. If it is determined that the current high-pressure pressure of the compressor is not less than the third rate reduction high-pressure pressure threshold of the compressor for the third set time in the third rate reduction mode, and it is determined that the current high-pressure pressure of the compressor is not less than the third rate reduction high-pressure pressure threshold of the compressor for a continuous control time in the third rate reduction mode, the compressor is controlled to stop, and the variable frequency heat pump unit is controlled to stop. And / or, The method for controlling the current frequency of the compressor according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor further comprises: It is determined whether the current high-pressure pressure of the compressor is greater than or equal to the fourth rate reduction high-pressure pressure threshold of the compressor and less than the high-pressure protection high-pressure pressure threshold of the compressor for a first set time in the fourth rate reduction mode. If it is determined that the current high-pressure pressure of the compressor is greater than or equal to the fourth rate reduction high-pressure pressure threshold of the compressor and less than the high-pressure protection high-pressure pressure threshold of the compressor for a first set time continuously in the preset fourth rate reduction mode, the compressor is controlled to enter the preset fourth rate reduction mode to control the current frequency of the compressor to reduce by a preset fourth rate reduction value; then it is determined again whether the current high-pressure pressure of the compressor is greater than or equal to the fourth rate reduction high-pressure pressure threshold of the compressor and less than the high-pressure protection high-pressure pressure threshold of the compressor for a first set time continuously in the preset fourth rate reduction mode; if yes, the current frequency of the compressor is controlled to reduce by a preset fourth rate reduction value every preset fourth rate reduction time; otherwise, the current frequency of the compressor is controlled again according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor. After the current frequency of the compressor is controlled to reduce by a preset fourth rate reduction value every preset fourth rate reduction time, it is determined whether the current high-pressure pressure of the compressor is less than the fourth rate reduction high-pressure pressure threshold of the compressor for a fourth time continuously in the preset fourth rate reduction mode. If it is determined that the current high-pressure pressure of the compressor is less than the fourth rate reduction high-pressure pressure threshold of the compressor for a fourth time continuously in the preset fourth rate reduction mode, the current frequency of the compressor is maintained for a fourth time in the preset fourth rate reduction mode, and then the compressor is controlled to exit the preset fourth rate reduction mode to exit the control of the current frequency of the compressor to reduce in the preset fourth rate reduction mode; then the current frequency of the compressor is controlled again according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor. If it is determined that the current high-pressure pressure of the compressor is not less than the fourth rate reduction high-pressure pressure threshold of the compressor for a fourth time continuously in the preset fourth rate reduction mode, and it is determined that the current high-pressure pressure of the compressor is not less than the fourth rate reduction high-pressure pressure threshold of the compressor for a continuous control time continuously in the preset fourth rate reduction mode, the compressor is controlled to stop, and the variable frequency heat pump unit is controlled to stop. And / or, The control of the current frequency of the compressor according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor further includes: It is determined whether the current high-pressure pressure of the compressor is greater than or equal to the high-pressure protection high-pressure pressure threshold of the compressor for a first set time continuously in the preset high-pressure protection mode. If it is determined that the current high-pressure pressure of the compressor is greater than or equal to the high-pressure protection high-pressure pressure threshold of the compressor for a first set time continuously in the preset high-pressure protection mode, the high-pressure switch of the variable frequency heat pump unit is controlled to be turned off, and the variable frequency heat pump unit is controlled to stop.

9. A control device of a variable frequency heat pump unit for implementing control of the variable frequency heat pump unit by a control method of the variable frequency heat pump unit as claimed in claim 1, characterized by The variable frequency heat pump unit has a compressor; a control device of the variable frequency heat pump unit comprises: An acquisition unit is configured to acquire a high-pressure pressure threshold of a block diagram control of the compressor and acquire a high-pressure protection pressure threshold of the compressor; A control unit is configured to determine a high-pressure pressure range of the compressor according to the high-pressure pressure threshold of the block diagram control of the compressor and the high-pressure protection pressure threshold of the compressor; The acquisition unit is further configured to acquire a current high-pressure pressure of the compressor and acquire a current frequency of the compressor after the variable frequency heat pump unit is powered on and the compressor is started; The control unit is further configured to control the current frequency of the compressor according to the current high-pressure pressure of the compressor and the high-pressure pressure range of the compressor, so as to adjust the current high-pressure pressure of the compressor to be within the high-pressure pressure range of the compressor.

10. A variable frequency heat pump unit, characterized by, Comprise: The control device of the variable frequency heat pump unit according to claim 9.

11. A storage medium, characterized by The storage medium comprises a stored program, wherein the program controls a device where the storage medium is located to execute the control method of the variable frequency heat pump unit according to any one of claims 1 to 8 when the program is running.

12. A computer program product comprising a computer program, characterized in that, The computer program is executed by a processor to implement the steps of the control method of the variable frequency heat pump unit according to any one of claims 1 to 8.

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