A control method and device of a variable frequency air conditioner, the variable frequency air conditioner and a storage medium

Abstract

The application discloses a control method and device of a variable frequency air conditioner, the variable frequency air conditioner and a storage medium, and relates to the technical field of air conditioners. The method comprises the following steps: in the case that the first cumulative running time of a compressor is greater than or equal to a first preset running time, a first preset control logic is executed based on the upper limit frequency control parameter of the compressor under the current running mode, in combination with the phase current value of the compressor, the frequency of the compressor, the outdoor environment temperature of the variable frequency air conditioner and the outdoor heat exchanger tube temperature of the variable frequency air conditioner; and in the case that the first cumulative running time of the compressor is less than the first preset running time, a second preset control logic is executed based on the upper limit frequency control parameter of the compressor under the current running mode, in combination with the phase current value of the compressor, the frequency of the compressor and the outdoor environment temperature of the variable frequency air conditioner, so that the frequency reduction protection of the phase current value is realized. According to the scheme, the frequency of the compressor is controlled to be reduced in advance when the running condition of the variable frequency air conditioner is abnormal, so that the running reliability and the heat exchange capacity are ensured.

Description

Technical Field

[0001] This invention belongs to the field of variable frequency air conditioning technology, specifically relating to a control method, device, variable frequency air conditioner and storage medium for a variable frequency air conditioner, and particularly to a method, device, variable frequency air conditioner and storage medium for controlling the upper frequency limit of a variable frequency air conditioner. Background Technology

[0002] To ensure the reliability of mainboard components, inverter products (such as inverter air conditioners) have a frequency reduction protection value set in the program to control the phase current value of the compressor motor. When the system pressure of an inverter air conditioner is high, the phase current value of the compressor motor increases, leading to a higher temperature rise of the mainboard components and a risk of reduced reliability. Therefore, the program needs to be designed with a frequency reduction protection value for the phase current value to control the compressor of the inverter air conditioner to reduce its frequency when the system pressure is high, thereby reducing the phase current value of the compressor motor and the temperature rise of the mainboard components.

[0003] During the operation of inverter air conditioners, there are also situations where the system pressure changes rapidly. In such cases, the phase current value of the compressor motor increases too quickly. When the frequency reduction protection of the phase current value is triggered, the pressure response during the compressor's frequency reduction process may be too slow, leading to overshoot. Therefore, when setting the frequency reduction protection value of the compressor motor's phase current value, this special situation is taken into consideration, and the protection value is set relatively low. However, setting the frequency reduction protection value too low means that under non-abnormal conditions (i.e., when the compressor motor's phase current value is within normal limits), the compressor frequency cannot increase further due to the limitation imposed by the frequency reduction protection value, thus restricting the heat exchange capacity of the inverter air conditioner.

[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, air conditioner, and storage medium for a variable frequency air conditioner. This addresses the issue that when the system pressure of a variable frequency air conditioner changes rapidly, the phase current value of the compressor motor increases too quickly. When the phase current reduction protection is triggered, the pressure response during the compressor's frequency reduction process is not timely, leading to overshoot. Therefore, when setting the frequency reduction protection value for the compressor motor's phase current value, the value is often set too low. However, setting the frequency reduction protection value too low can result in the compressor being affected by the phase current reduction protection even under non-abnormal conditions (i.e., when the phase current value of the compressor motor is within normal range). The limitation of the protection value prevents the compressor frequency from increasing further, thus restricting the heat exchange capacity of the inverter air conditioner. To address this, the system monitors the operation of the inverter air conditioner. When the operation is within the preset normal range, the compressor frequency is controlled based on preset phase current limiting and reducing current values ​​to ensure heat exchange capacity. Conversely, when the operation deviates from the preset normal range, the preset phase current limiting and reducing current values ​​are reduced in advance, and the compressor frequency is controlled based on these reduced values. This prevents overshoot caused by untimely pressure response during compressor frequency reduction, ensuring the reliability of the inverter air conditioner.

[0006] This invention provides a control method for a variable frequency air conditioner, comprising: after the compressor of the variable frequency air conditioner starts, timing the running time of the compressor after startup to obtain a first cumulative running time of the compressor; determining the current operating mode of the variable frequency air conditioner; and in the current operating mode of the variable frequency air conditioner, determining an upper limit frequency control parameter of the compressor of the variable frequency air conditioner, denoted as the upper limit frequency control parameter of the compressor in the current operating mode; the current operating mode of the variable frequency air conditioner is a heating mode or a cooling mode; acquiring the phase current value of the compressor, acquiring the frequency of the compressor, acquiring the outdoor ambient temperature of the variable frequency air conditioner, and acquiring the outdoor heat exchanger tube temperature of the variable frequency air conditioner; and, if the first cumulative running time of the compressor is greater than or equal to a first preset running time, based on the... In the current operating mode, the compressor's upper limit frequency control parameters, combined with the compressor's phase current value, compressor frequency, outdoor ambient temperature of the inverter air conditioner, and outdoor heat exchanger pipe temperature of the inverter air conditioner, execute either the first preset control logic or the second preset control logic of the compressor's phase current value frequency reduction protection mode to achieve frequency reduction protection for the compressor's phase current value; if the compressor's first cumulative operating time is less than the first preset operating time, based on the compressor's upper limit frequency control parameters in the current operating mode, combined with the compressor's phase current value, compressor frequency, and outdoor ambient temperature of the inverter air conditioner, execute the second preset control logic of the compressor's phase current value frequency reduction protection mode to achieve frequency reduction protection for the compressor's phase current value.

[0007] In some implementations, based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger tube temperature of the inverter air conditioner, a first preset control logic or a second preset control logic of the frequency reduction protection mode for the phase current value of the compressor is executed to achieve frequency reduction protection for the phase current value of the compressor. This includes: determining the rate of change of the outdoor heat exchanger tube temperature of the inverter air conditioner within a continuously set time period; and determining whether the rate of change of the outdoor heat exchanger tube temperature of the inverter air conditioner is greater than or equal to a set tube temperature change rate; if it is determined that the rate of change of the outdoor heat exchanger tube temperature of the inverter air conditioner is greater than or equal to the set tube temperature change rate, then based on the... In the current operating mode, the compressor's upper limit frequency control parameter, combined with the compressor's phase current value, compressor frequency, and outdoor ambient temperature of the inverter air conditioner, executes the first preset control logic of the compressor's phase current value frequency reduction protection mode to achieve frequency reduction protection for the compressor's phase current value; if it is determined that the rate of change of the outdoor heat exchanger pipe temperature of the inverter air conditioner is less than the set pipe temperature change rate, then based on the compressor's upper limit frequency control parameter in the current operating mode, combined with the compressor's phase current value, compressor frequency, and outdoor ambient temperature of the inverter air conditioner, executes the second preset control logic of the compressor's phase current value frequency reduction protection mode to achieve frequency reduction protection for the compressor's phase current value.

[0008] In some embodiments, the upper limit frequency control parameters of the compressor in the current operating mode include: the frequency limiting current value of the compressor in the current operating mode, the frequency reduction current value of the compressor in the current operating mode, a first frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, a second frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, and the upper limit frequency of the compressor in the current operating mode; based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, the first preset control logic of the frequency reduction protection mode of the compressor phase current value is executed to realize the frequency reduction protection of the compressor phase current value, including: reducing the frequency limiting current value of the compressor in the current operating mode by a set current value, and reducing the frequency reduction current value of the compressor in the current operating mode by a set current value; determining the compressor If the phase current value of the compressor is greater than or equal to the difference between the first frequency limiting current value and the set current value, then the compressor frequency is reduced until the phase current value of the compressor is reduced to the point where it exits the frequency reduction protection mode of the compressor's phase current value. At the same time, the upper limit frequency of the compressor in the current operating mode is reduced by a set frequency value to correct the upper limit frequency of the compressor. If the phase current value of the compressor is less than the difference between the first frequency limiting current value and the set current value, then: if the phase current value of the compressor is greater than or equal to the difference between the second frequency limiting current value and the set current value, then the compressor frequency is kept at the current frequency and the compressor frequency is not allowed to increase; if the phase current value of the compressor is less than the difference between the second frequency limiting current value and the set current value, then the compressor frequency is set to the preset target frequency and the compressor frequency is allowed to increase.

[0009] In some implementations, based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, a first preset control logic for a frequency reduction protection mode of the compressor's phase current value is executed to achieve frequency reduction protection of the compressor's phase current value. This further includes: after reducing the upper limit frequency of the compressor under the current operating mode by a set frequency value, re-timing the compressor's operating time to obtain a second cumulative operating time of the compressor; and within the second cumulative operating time of the compressor, determining the rate of change of the outdoor ambient temperature of the air conditioner; and determining whether the second cumulative operating time of the compressor is met. If the running time is greater than or equal to the second preset running time, or the rate of change of the outdoor ambient temperature of the air conditioner is greater than or equal to the set temperature change rate, then exit the frequency reduction protection mode of the compressor's phase current value and stop correcting the upper limit frequency of the compressor in the current operating mode; otherwise, return to the previous state and re-execute the first preset control logic or the second preset control logic of the frequency reduction protection mode of the compressor's phase current value based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger pipe temperature of the inverter air conditioner, so as to realize the frequency reduction protection of the compressor's phase current value.

[0010] In some embodiments, the upper limit frequency control parameters of the compressor in the current operating mode include: the frequency limiting current value of the compressor in the current operating mode, the frequency reduction current value of the compressor in the current operating mode, a first frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, a second frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, and the upper limit frequency of the compressor in the current operating mode; based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, the second preset control logic of the frequency reduction protection mode of the compressor phase current value is executed to realize the frequency reduction protection of the compressor phase current value, including: determining the phase current of the compressor. The compressor's phase current value is determined to be greater than or equal to the first frequency limiting current value. If the compressor's phase current value is determined to be greater than or equal to the first frequency limiting current value, the compressor's frequency is reduced until the phase current value is reduced to the point where the compressor's phase current value's frequency reduction protection mode is exited. Simultaneously, the compressor's upper limit frequency in the current operating mode is reduced by a set frequency value to correct the compressor's upper limit frequency. If the compressor's phase current value is determined to be less than the first frequency limiting current value, then: if the compressor's phase current value is greater than or equal to the second frequency limiting current value, the compressor's frequency is kept at its current frequency, and the compressor's frequency is not allowed to increase; if the compressor's phase current value is less than the second frequency limiting current value, the compressor's frequency is set to a preset target frequency, and the compressor's frequency is allowed to increase.

[0011] In some implementations, based on the compressor's upper limit frequency control parameters under the current operating mode, combined with the compressor's phase current value, compressor frequency, and outdoor ambient temperature of the inverter air conditioner, a second preset control logic for a frequency reduction protection mode of the compressor's phase current value is executed to achieve frequency reduction protection of the compressor's phase current value. This further includes: after reducing the compressor's upper limit frequency under the current operating mode by a set frequency value, re-timing the compressor's operating time to obtain a second cumulative operating time; and within the second cumulative operating time of the compressor, determining the rate of change of the outdoor ambient temperature of the air conditioner; and determining whether the required time has been met. If the second cumulative running time of the compressor is greater than or equal to the second preset running time, or the rate of change of the outdoor ambient temperature of the air conditioner is greater than or equal to the set temperature change rate, then exit the frequency reduction protection mode of the compressor's phase current value and stop correcting the upper limit frequency of the compressor in the current operating mode; otherwise, return to the previous state and re-execute the second preset control logic of the frequency reduction protection mode of the compressor's phase current value based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, so as to realize the frequency reduction protection of the compressor's phase current value.

[0012] In conjunction with the above method, another aspect of the present invention provides a control device for a variable frequency air conditioner, comprising: a control unit configured to time the running time of the compressor after it starts, thereby obtaining a first cumulative running time of the compressor; the control unit is further configured to determine the current operating mode of the variable frequency air conditioner; and, in the current operating mode of the variable frequency air conditioner, determine an upper limit frequency control parameter of the compressor, denoted as the upper limit frequency control parameter of the compressor in the current operating mode; the current operating mode of the variable frequency air conditioner is a heating mode or a cooling mode; an acquisition unit configured to acquire the phase current value of the compressor, acquire the frequency of the compressor, acquire the outdoor ambient temperature of the variable frequency air conditioner, and acquire the outdoor heat exchanger pipe temperature of the variable frequency air conditioner; the control unit is further configured to time the first cumulative running time of the compressor after it starts, thereby obtaining a first cumulative running time of the compressor. When the operating time is equal to or greater than a first preset operating time, based on the upper limit frequency control parameters of the compressor under the current operating mode, and in combination with the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger pipe temperature of the inverter air conditioner, the control unit executes a first preset control logic or a second preset control logic for a frequency reduction protection mode of the compressor's phase current value to achieve frequency reduction protection of the compressor's phase current value. The control unit is further configured to, when the first cumulative operating time of the compressor is less than the first preset operating time, based on the upper limit frequency control parameters of the compressor under the current operating mode, and in combination with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, execute a second preset control logic for a frequency reduction protection mode of the compressor's phase current value to achieve frequency reduction protection of the compressor's phase current value.

[0013] In some implementations, the control unit, based on the upper limit frequency control parameters of the compressor under the current operating mode, and in conjunction with the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger tube temperature of the inverter air conditioner, executes a first preset control logic or a second preset control logic for a frequency reduction protection mode of the compressor's phase current value to achieve frequency reduction protection of the compressor's phase current value. This includes: determining the rate of change of the outdoor heat exchanger tube temperature of the inverter air conditioner within a continuously set time period; and determining whether the rate of change of the outdoor heat exchanger tube temperature of the inverter air conditioner is greater than or equal to a set tube temperature change rate; if it is determined that the rate of change of the outdoor heat exchanger tube temperature of the inverter air conditioner is greater than or equal to the set tube temperature change rate, then... Based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, the first preset control logic of the frequency reduction protection mode of the compressor phase current value is executed to achieve frequency reduction protection of the compressor phase current value; if it is determined that the rate of change of the outdoor heat exchanger pipe temperature of the inverter air conditioner is less than the set pipe temperature change rate, then based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, the second preset control logic of the frequency reduction protection mode of the compressor phase current value is executed to achieve frequency reduction protection of the compressor phase current value.

[0014] In some embodiments, the upper limit frequency control parameters of the compressor in the current operating mode include: the frequency limiting current value of the compressor in the current operating mode, the frequency reduction current value of the compressor in the current operating mode, a first frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, a second frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, and the upper limit frequency of the compressor in the current operating mode; the control unit, based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, executes a first preset control logic for the frequency reduction protection mode of the compressor's phase current value to achieve frequency reduction protection of the compressor's phase current value, including: reducing the frequency limiting current value of the compressor in the current operating mode by a set current value, and reducing the frequency reduction current value of the compressor in the current operating mode by a set current value; determining the... If the compressor's phase current value is greater than or equal to the difference between the first frequency-limiting current value and the set current value, then the compressor's frequency is reduced until the compressor's phase current value is reduced to the point where it exits the frequency reduction protection mode. Simultaneously, the compressor's upper limit frequency in the current operating mode is reduced by a set frequency value to correct the compressor's upper limit frequency. If the compressor's phase current value is less than the difference between the first frequency-limiting current value and the set current value, then: if the compressor's phase current value is greater than or equal to the difference between the second frequency-limiting current value and the set current value, then the compressor's frequency is maintained at its current frequency, and the compressor's frequency is not allowed to increase; if the compressor's phase current value is less than the difference between the second frequency-limiting current value and the set current value, then the compressor's frequency is set to a preset target frequency, and the compressor's frequency is allowed to increase.

[0015] In some embodiments, the control unit, based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, executes a first preset control logic for a frequency reduction protection mode of the compressor's phase current value to achieve frequency reduction protection of the compressor's phase current value. This further includes: after reducing the upper limit frequency of the compressor in the current operating mode by a set frequency value, re-timing the compressor's operating time to obtain a second cumulative operating time of the compressor; and within the second cumulative operating time of the compressor, determining the rate of change of the outdoor ambient temperature of the air conditioner; and determining whether the compressor's first... If the cumulative running time is greater than or equal to the second preset running time, or the rate of change of the outdoor ambient temperature of the air conditioner is greater than or equal to the set temperature change rate, then exit the frequency reduction protection mode of the compressor's phase current value and stop correcting the upper limit frequency of the compressor in the current operating mode; otherwise, return to the previous state and re-execute the first preset control logic or the second preset control logic of the frequency reduction protection mode of the compressor's phase current value based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger tube temperature of the inverter air conditioner, so as to realize the frequency reduction protection of the compressor's phase current value.

[0016] In some embodiments, the upper limit frequency control parameters of the compressor in the current operating mode include: the frequency limiting current value of the compressor in the current operating mode, the frequency reduction current value of the compressor in the current operating mode, a first frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, a second frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, and the upper limit frequency of the compressor in the current operating mode; the control unit, based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, executes a second preset control logic for the frequency reduction protection mode of the compressor's phase current value to achieve frequency reduction protection of the compressor's phase current value, including: determining the compressor If the phase current value of the compressor is greater than or equal to the first frequency limiting current value, then the compressor frequency is reduced until the phase current value of the compressor is reduced to the point where the compressor exits the frequency reduction protection mode. Simultaneously, the upper limit frequency of the compressor in the current operating mode is reduced by a set frequency value to correct the upper limit frequency of the compressor. If the phase current value of the compressor is less than the first frequency limiting current value, then: if the phase current value of the compressor is greater than or equal to the second frequency limiting current value, then the compressor frequency is maintained at the current frequency and the compressor frequency is not allowed to increase; if the phase current value of the compressor is less than the second frequency limiting current value, then the compressor frequency is set to a preset target frequency and the compressor frequency is allowed to increase.

[0017] In some embodiments, the control unit, based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, executes a second preset control logic for a frequency reduction protection mode of the compressor's phase current value to achieve frequency reduction protection of the compressor's phase current value. This further includes: after reducing the upper limit frequency of the compressor in the current operating mode by a set frequency value, re-timing the compressor's operating time to obtain a second cumulative operating time of the compressor; and determining the rate of change of the outdoor ambient temperature of the air conditioner within the second cumulative operating time of the compressor. If the second cumulative running time of the compressor is greater than or equal to the second preset running time, or if the rate of change of the outdoor ambient temperature of the air conditioner is greater than or equal to the set temperature change rate, then exit the frequency reduction protection mode of the compressor's phase current value and stop correcting the upper limit frequency of the compressor in the current operating mode; otherwise, return to the previous state and re-execute the second preset control logic of the frequency reduction protection mode of the compressor's phase current value based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, so as to realize the frequency reduction protection of the compressor's phase current value.

[0018] In conjunction with the above-mentioned device, the present invention further provides a variable frequency air conditioner, comprising: the control device for the variable frequency air conditioner described above.

[0019] 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 above-described control method for a variable frequency air conditioner.

[0020] Therefore, the solution of this invention, after the compressor of the inverter air conditioner starts, based on the length of the compressor's running time after startup, and considering the operating mode of the inverter air conditioner, the compressor's phase current value, the compressor frequency, the outdoor ambient temperature, the outdoor heat exchanger tube temperature, and the indoor heat exchanger tube temperature, controls the compressor frequency according to preset frequency-limiting current values ​​and frequency-reducing current values ​​when the inverter air conditioner's operating conditions are within a preset normal range, thereby ensuring the heat exchange capacity of the inverter air conditioner; when the inverter air conditioner's operating conditions are not within a preset normal range, the preset frequency-limiting current value and frequency-reducing current value are reduced in advance, and the frequency-limiting current value of the phase current value is adjusted according to the reduced phase current value. The compressor frequency is controlled by the phase current limiting current and the frequency reduction current value. Thus, by monitoring the operation of the inverter air conditioner, when the operation is within the preset normal range, the compressor frequency is controlled according to the preset phase current limiting current and frequency reduction current values ​​to ensure the heat exchange capacity of the inverter air conditioner. When the operation is not within the preset normal range, the preset phase current limiting current and frequency reduction current values ​​are reduced in advance, and the compressor frequency is controlled according to the reduced phase current limiting current and frequency reduction current values ​​to avoid overshoot caused by untimely pressure response during compressor frequency reduction, thus ensuring the operational reliability of the inverter air conditioner.

[0021] 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.

[0022] 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

[0023] Figure 1 This is a flowchart illustrating an embodiment of the control method for a variable frequency air conditioner according to the present invention;

[0024] Figure 2 This is a flowchart illustrating an embodiment of the first preset control logic for executing a frequency reduction protection mode of the compressor's phase current value in the method of the present invention, which combines the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger tube temperature of the inverter air conditioner.

[0025] Figure 3 This is a flowchart illustrating an embodiment of the first preset control logic for executing a frequency reduction protection mode of the compressor's phase current value in the method of the present invention, which combines the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner.

[0026] Figure 4This is a flowchart illustrating an embodiment of the method of the present invention, which corrects the upper limit frequency of the compressor under the current operating mode after exiting the frequency reduction protection mode of the compressor's phase current value under the first preset control logic.

[0027] Figure 5 This is a flowchart illustrating an embodiment of the second preset control logic in the method of the present invention, which combines the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner to execute the frequency reduction protection mode of the compressor's phase current value.

[0028] Figure 6 This is a flowchart illustrating an embodiment of the method of the present invention, which corrects the upper limit frequency of the compressor under the current operating mode after exiting the frequency reduction protection mode of the compressor's phase current value under the second preset control logic.

[0029] Figure 7 This is a schematic diagram of the structure of an embodiment of the control device for a variable frequency air conditioner of the present invention;

[0030] Figure 8 A schematic diagram of control logic for an embodiment of a method for controlling the upper frequency limit of a variable frequency air conditioner;

[0031] Figure 9 The diagram shows the curves of the limit value of the phase current of the inverter air conditioner as a function of the outdoor ambient temperature. (a) shows the curves of the limit value of the phase current of the inverter air conditioner as a function of the outdoor ambient temperature in heating mode, and (b) shows the curves of the limit value of the phase current of the inverter air conditioner as a function of the outdoor ambient temperature in cooling mode.

[0032] Figure 10 A schematic diagram of the control logic for an embodiment of a step-by-step control method for adjusting the phase current value of a variable frequency air conditioner;

[0033] Figure 11 Detailed control logic diagram of an embodiment of a method for controlling the upper frequency limit of an inverter air conditioner Figure 1 ;

[0034] Figure 12 Detailed control logic diagram of an embodiment of a method for controlling the upper frequency limit of an inverter air conditioner Figure 2 .

[0035] Referring to the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows:

[0036] 102 - Acquisition unit; 104 - Control unit. Detailed Implementation

[0037] 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.

[0038] In existing solutions, limits are set on the phase current values ​​of the compressor motor under different operating conditions (i.e., frequency reduction protection values ​​for phase current). Below the limit, the compressor operates at the target frequency; above the limit, it operates at reduced frequency. However, this solution does not consider the issue of early intervention when the phase current value of the compressor motor changes rapidly, and it still has shortcomings in the protection of mainboard components. For example, the protection of mainboard components in existing solutions cannot distinguish between normal and abnormal modes. In abnormal modes, such as valve blockage or fan stall, the current value increases rapidly, while the current detection speed lags behind. To prevent mainboard burnout, a lower shutdown current is designed to achieve early protection. However, in the normal operating mode of the air conditioner, the current increases very slowly, and the current detection speed can keep up with the current change rate. The shutdown current can be designed to be higher to ensure maximum capacity. However, without distinguishing between normal and abnormal modes, the shutdown current design must be lower, which sacrifices the heat exchange performance of the air conditioner.

[0039] Therefore, the present invention proposes a control method for a variable frequency air conditioner, specifically a method for controlling the upper limit of the frequency of a variable frequency air conditioner. By calculating the rate of change of the system pressure of the variable frequency air conditioner, the control system of the variable frequency air conditioner is distinguished as being in a normal or abnormal condition: if it is in a normal condition, it is controlled according to the originally set phase current protection value; if it is in an abnormal condition, the compressor frequency is intervened in advance by reducing the frequency limiting current value and the frequency reduction current value of the phase current value, so as to achieve the purpose of early protection and improve the reliability of the main board components of the variable frequency air conditioner.

[0040] According to embodiments of the present invention, a control method for a variable frequency air conditioner is provided, such as... Figure 1 The diagram shows a flowchart of an embodiment of the method of the present invention. The variable frequency air conditioner has a compressor, an outdoor heat exchanger, and an indoor heat exchanger; the control method of the variable frequency air conditioner includes steps S110 to S150.

[0041] In step S110, after the compressor of the variable frequency air conditioner starts, the running time of the compressor after starting is timed to obtain the first cumulative running time of the compressor.

[0042] In step S120, the current operating mode of the inverter air conditioner is determined; and in the current operating mode of the inverter air conditioner, the upper limit frequency control parameter of the compressor of the inverter air conditioner is determined and recorded as the upper limit frequency control parameter of the compressor in the current operating mode; the current operating mode of the inverter air conditioner is either heating mode or cooling mode.

[0043] In step S130, the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger tube temperature of the inverter air conditioner are obtained. Wherein, in cooling mode, the outdoor heat exchanger tube temperature of the inverter air conditioner is the condensing temperature T. 冷 In heating mode, the outdoor heat exchanger tube temperature of the inverter air conditioner is the evaporation temperature T. 蒸 .

[0044] In step S140, if the first cumulative running time of the compressor is greater than or equal to the first preset running time, based on the upper limit frequency control parameters of the compressor under the current operating mode, and in combination with the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger pipe temperature of the inverter air conditioner, the first preset control logic or the second preset control logic of the frequency reduction protection mode for the phase current value of the compressor is executed to achieve frequency reduction protection for the phase current value of the compressor. The first preset running time is, for example, time t.

[0045] In step S150, if the first cumulative running time of the compressor is less than the first preset running time, based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, the second preset control logic of the frequency reduction protection mode of the compressor phase current value is executed to realize the frequency reduction protection of the compressor phase current value.

[0046] Specifically, Figure 8 This is a schematic diagram of the control logic of one embodiment of a method for controlling the upper frequency limit of a variable frequency air conditioner. Figure 8 As shown, the present invention provides a method for controlling the upper frequency limit of a variable frequency air conditioner, comprising:

[0047] S10. After the inverter air conditioner is powered on and turned on, obtain the running time of the compressor after it starts, and then execute step S11.

[0048] S11. Determine the length of the compressor's running time after it is turned on, so as to make further determinations when distinguishing control schemes based on the length of the compressor's running time after it is turned on. Then, proceed to step S12.

[0049] S12. Determine whether the phase current value of the compressor is controlled according to the normal limit or whether it is necessary to add a judgment on abnormal conditions, and then proceed to step S13.

[0050] S13. Obtain the operating mode and outdoor ambient temperature of the inverter air conditioner. Based on the operating mode and outdoor ambient temperature of the inverter air conditioner, determine the limit value of the compressor phase current. Then, execute step S14.

[0051] S14. Obtain the evaporator temperature and condenser temperature of the inverter air conditioner, and obtain the compressor frequency and phase current value, then execute step S15.

[0052] S15. Determine whether the inverter air conditioner has entered the phase current value reduction protection mode: If the inverter air conditioner's control system is in normal condition, it is only necessary to compare the phase current value with the preset value and adjust the compressor frequency; if the inverter air conditioner's control system is in abnormal condition, it is necessary to lower the limit of the phase current value on the basis of normal condition in order to achieve the purpose of intervening in the compressor frequency in advance. Adjust the compressor frequency control according to the updated phase current value limit, and then execute step S16.

[0053] S16. Control the compressor frequency based on the frequency limiting protection of the phase current value and the frequency reduction current value, and then execute step S17.

[0054] S17. Determine whether the inverter air conditioner has exited the frequency reduction protection mode of the phase current value, and then execute step S18.

[0055] Figure 9 The diagram shows the curve of the phase current limit of a variable frequency air conditioner (i.e., the phase current limit) changing with the outdoor ambient temperature. (a) is a diagram of the curve of the phase current limit of a variable frequency air conditioner changing with the outdoor ambient temperature in heating mode, and (b) is a diagram of the curve of the phase current limit of a variable frequency air conditioner changing with the outdoor ambient temperature in cooling mode. Figure 9 The correlation between the phase current limit of the variable frequency air conditioner control system and the outdoor ambient temperature in different modes is presented. Specifically, when the outdoor ambient temperature is low, the temperature rise of the main board components is low, and the allowable phase current limit can be higher. As the outdoor ambient temperature increases, the phase current limit gradually decreases.

[0056] See Figure 9 In the example shown, since the outdoor ambient temperature allowed in heating mode is lower than that allowed in cooling mode, the limit for the maximum phase current value in heating mode is higher than that in cooling mode.

[0057] Figure 10 This is a schematic diagram of the control logic of an embodiment of a step-by-step control method for adjusting the phase current value of a variable frequency air conditioner. Figure 10 A step-by-step control scheme is presented for the control system of a variable frequency air conditioner when controlling the phase current value. For example... Figure 10 As shown, the step-by-step control method for the phase current value of a variable frequency air conditioner proposed in this invention includes:

[0058] Step 21: When the phase current value gradually increases, if the preset phase current value is reached, the compressor frequency is allowed to increase slowly.

[0059] Step 22: When the phase current value continues to rise and reaches the preset phase current value limit current value, the compressor frequency is not allowed to continue to rise.

[0060] Step 23: When the phase current value continues to rise and reaches the preset phase current value for frequency reduction, the compressor frequency should be rapidly reduced.

[0061] Among them, the preset phase current value is the gradual rise current value < the preset phase current value is the frequency limiting current value < the preset phase current value is the frequency reduction current value.

[0062] This invention provides a solution for controlling the upper frequency limit of a variable frequency air conditioner. By detecting the rate of change in the system pressure (specifically, the high-pressure system pressure), it quickly determines whether the system pressure and current (i.e., phase current value) are in abnormal or normal conditions. When the unit is in a normal state, the compressor frequency is reduced and limited according to the normal phase current value's frequency reduction current limit (i.e., the phase current value's frequency reduction current limit and the phase current value's frequency limiting current limit), ensuring the performance of the variable frequency air conditioner under extreme operating conditions. When the unit is in an abnormal state, the compressor frequency control is intervened in advance to improve the reliability of the mainboard components of the variable frequency air conditioner. The performance of the variable frequency air conditioner under extreme operating conditions refers to: during cooling, its cooling performance at an outdoor temperature of 54 degrees Celsius in tropical regions such as the Middle East or 48 degrees Celsius in temperate regions; and during heating, its heating capacity at an outdoor temperature of -15 degrees Celsius or lower.

[0063] In some embodiments, when the first cumulative running time of the compressor is greater than or equal to the first preset running time, in step S140, based on the upper limit frequency control parameter of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger tube temperature of the inverter air conditioner, the first preset control logic or the second preset control logic of the frequency reduction protection mode of the compressor phase current value is executed to realize the specific process of frequency reduction protection of the compressor phase current value. See the following exemplary description.

[0064] The following is combined Figure 2The flowchart shown is an embodiment of the method of the present invention, which combines the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger tube temperature of the inverter air conditioner to execute the first preset control logic of the frequency reduction protection mode of the compressor's phase current value. It further illustrates the specific process of executing the first preset control logic of the frequency reduction protection mode of the compressor's phase current value in step S140, which combines the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger tube temperature of the inverter air conditioner, including steps S210 to S230.

[0065] Step S210: Within a continuously set time period, determine the rate of change of the outdoor heat exchanger pipe temperature of the inverter air conditioner; and determine whether the rate of change of the outdoor heat exchanger pipe temperature of the inverter air conditioner is greater than or equal to the set pipe temperature change rate. The set time period is, for example, 30 seconds, and the set pipe temperature change rate is, for example, a third preset value. In cooling mode, the rate of change of the outdoor heat exchanger pipe temperature of the inverter air conditioner is (T... 冷 '-T 冷 ) / T 冷 The rate of change of the outdoor heat exchanger pipe temperature of the inverter air conditioner in heating mode is (T 蒸 '-T 蒸 ) / T 蒸 :(T 冷 '-T 冷 ) / T 冷 .

[0066] Step S220: If it is determined that the rate of change of the outdoor heat exchanger pipe temperature of the variable frequency air conditioner is greater than or equal to the set pipe temperature change rate, then based on the upper limit frequency control parameter of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the variable frequency air conditioner, the first preset control logic of the frequency reduction protection mode of the compressor phase current value is executed to realize the frequency reduction protection of the compressor phase current value.

[0067] Step S230: If it is determined that the rate of change of the outdoor heat exchanger pipe temperature of the variable frequency air conditioner is less than the set pipe temperature change rate, then based on the upper limit frequency control parameter of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the variable frequency air conditioner, the second preset control logic of the frequency reduction protection mode of the compressor phase current value is executed to realize the frequency reduction protection of the compressor phase current value.

[0068] Specifically, Figure 11 Detailed control logic diagram of an embodiment of a method for controlling the upper frequency limit of an inverter air conditioner Figure 1 , Figure 12Detailed control logic diagram of an embodiment of a method for controlling the upper frequency limit of an inverter air conditioner Figure 2 . Figure 11 and Figure 12 A detailed control logic operation reference example for a variable frequency air conditioner control system is provided. For example... Figure 11 and Figure 12 As shown, the method for controlling the upper frequency limit of a variable frequency air conditioner proposed in this invention specifically includes:

[0069] Step S31: The inverter air conditioner is turned on, and the compressor changes from the off state to the on state. Then, step S32 is executed.

[0070] Step S32: Set the compressor running time t after startup. 压 Timing is initiated, followed by step S33. During the compressor start-up phase, the compressor frequency gradually increases from 0Hz to the target frequency. During this process, the system high pressure of the compressor changes drastically, and the phase current value of the compressor increases rapidly; however, this is normal. Therefore, during the start-up phase, only the compressor's running time t after startup is recorded. 压 The timer is set, but the compressor's operation is not judged to be normal or abnormal during the startup phase.

[0071] Step S33: Determine whether the compressor starts running for the specified time t. 压 ≥Preset value: If yes, proceed to step S41; otherwise, proceed to step S51. In step S33, first determine the continuous running time after the compressor starts, i.e., the running time t after the compressor starts. 压 The running time t after the compressor starts 压 Determine which control scheme is used to control the phase current value of the compressor.

[0072] Step S41: If the compressor runs for t days after startup... 压 If the value is greater than or equal to the preset value, then the following steps will be executed, such as steps S42 to S46.

[0073] Step S42: First determine whether the inverter air conditioner is in cooling mode or heating mode, so as to determine the upper limit frequency control value of the compressor under each operating condition based on the inverter air conditioner's operating mode.

[0074] Step S43: Obtain the compressor phase current value I, compressor frequency P1, and outdoor ambient temperature T. 外 Evaporation temperature T 蒸 Condensation temperature T 冷 Data. The data obtained here is used to prepare for subsequent calculations and judgments.

[0075] Step S44, in cooling mode, continuously detect for a certain period of time, for example, 30 seconds. If the initial detection value T...冷 'Compared with the last detection value T 冷 The difference satisfies: (T) 冷 '-T 冷 ) / T 冷 If the value is greater than or equal to the third preset value, then proceed according to step S45; otherwise, proceed according to step t. 压 The program execution with the preset value is to execute the program according to step S51.

[0076] In heating mode, continuous monitoring is performed for a certain period of time, for example, 30 seconds. If the initial detection value T... 蒸 'Compared with the last detection value T 蒸 The difference satisfies: (T) 蒸 '-T 蒸 ) / T 蒸 If the value is greater than or equal to the third preset value, then proceed according to step S45; otherwise, proceed according to step t. 压 The program execution with the preset value is to execute the program according to step S51.

[0077] If this standard is met, it indicates that the system pressure of the inverter air conditioner and the phase current value I of the compressor are changing rapidly, and the whole unit is in an abnormal state. It is necessary to intervene in advance by comparing the phase current value I of the compressor with the preset value and adjusting the frequency P1 of the compressor in advance.

[0078] Considering that when the system pressure of a variable frequency air conditioner changes rapidly, the phase current value of the compressor motor increases too quickly, and when the frequency reduction protection of the phase current value is triggered, the compressor's frequency reduction process may result in overshoot due to untimely pressure response. The solution of this invention detects the system parameters (such as system pressure) of the variable frequency air conditioner, calculates the rate of change of the detected data (such as system pressure), and distinguishes between abnormal and normal operation of the variable frequency air conditioner based on the rate of change. If an abnormality occurs, the frequency limiting and frequency reduction protection of the phase current value intervenes in advance, reducing the possibility of overshoot caused by untimely pressure response during compressor frequency reduction, and improving the reliability of the mainboard components of the variable frequency air conditioner.

[0079] In the solution of this invention, by calculating the rate of change of the system pressure of the variable frequency air conditioner, it is possible to distinguish whether the control system of the variable frequency air conditioner is in a normal or abnormal state: if it is in a normal state, it is controlled according to the originally set phase current protection value; if it is in an abnormal state, the frequency limiting current value and the frequency reduction current value of the phase current value are reduced to intervene in the compressor frequency in advance, so as to achieve the purpose of early protection and improve the reliability of the main board components of the variable frequency air conditioner.

[0080] In some embodiments, the upper limit frequency control parameter of the compressor in the current operating mode includes: the frequency limiting current value of the compressor in the current operating mode, the frequency reduction current value of the compressor in the current operating mode, the first frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, the second frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, and the upper limit frequency of the compressor in the current operating mode.

[0081] In step S220, based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, the first preset control logic of the frequency reduction protection mode of the compressor phase current value is executed to realize the specific process of frequency reduction protection of the compressor phase current value. See the following exemplary description.

[0082] The following is combined Figure 3 The flowchart shown is an embodiment of the method of the present invention, which combines the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner to execute the first preset control logic of the phase current value of the compressor for frequency reduction protection mode. The flowchart further illustrates the specific process of executing the first preset control logic of the phase current value of the compressor for frequency reduction protection mode in step S220, which combines the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, including steps S310 to S340.

[0083] Step S310: Reduce the frequency-limiting current value of the compressor in the current operating mode by a set current value, and reduce the frequency-reducing current value of the compressor in the current operating mode by a set current value. The set current value is as follows: .

[0084] Step S320: Determine whether the phase current value of the compressor is greater than or equal to the difference between the first frequency-limiting current value and the set current value. Wherein, the first frequency-limiting current value corresponds to the outdoor ambient temperature T of the specified mode. 外 The corresponding first preset value for frequency reduction.

[0085] Step S330: If it is determined that the phase current value of the compressor is greater than or equal to the difference between the first frequency-limiting current value and the set current value, then the frequency of the compressor is reduced until the phase current value of the compressor is reduced to the point where the frequency reduction protection mode of the compressor's phase current value is exited; simultaneously, the upper limit frequency of the compressor in the current operating mode is reduced by a set frequency value to correct the upper limit frequency of the compressor. The set frequency value is as follows: .

[0086] Step S340: If it is determined that the phase current value of the compressor is less than the difference between the first frequency limiting current value and the set current value, then:

[0087] First, if the phase current value of the compressor is greater than or equal to the difference between the second frequency limiting current value and the set current value, the compressor frequency is kept at the current frequency and the compressor frequency is not allowed to increase. Then, the process returns to the previous state and, based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the compressor phase current value, the compressor frequency, and the outdoor ambient temperature of the inverter air conditioner, the first preset control logic of the frequency reduction protection mode of the compressor phase current value is executed to realize the frequency reduction protection of the compressor phase current value.

[0088] Second, if the compressor's phase current value is less than the difference between the second frequency-limiting current value and the set current value, the compressor's frequency is set to a preset target frequency, and the compressor's frequency is allowed to increase. Then, the process returns to the previous state to re-execute the first preset control logic for the compressor's phase current value frequency reduction protection mode based on the compressor's upper limit frequency control parameters under the current operating mode, combined with the compressor's phase current value, the compressor's frequency, and the outdoor ambient temperature of the inverter air conditioner. This achieves frequency reduction protection for the compressor's phase current value. The second frequency-limiting current value corresponds to the outdoor ambient temperature T of the corresponding mode. 外 The corresponding second preset value for frequency reduction.

[0089] Specifically, such as Figure 11 and Figure 12 As shown, the method for controlling the upper frequency limit of a variable frequency air conditioner proposed in this invention further includes:

[0090] Step S45: Corresponding operating conditions for different operating modes: Reduce the current value of the compressor's frequency limiting current value and frequency reducing current value. The reduction value is... Then, proceed to step S46; where, This is the preset value of the program, such as 2A~5A. At this time, the compressor frequency is intervened in advance by reducing the compressor's frequency limiting current value and frequency reduction current value.

[0091] Step S46: Compare the phase current value I of the compressor with the preset value, and perform the following steps according to the comparison result, such as steps S461 to S463.

[0092] Step S461: If the compressor phase current value I ≥ the outdoor ambient temperature T of the corresponding mode 外 The corresponding first preset value for frequency reduction - If the compressor frequency P1 is rapidly reduced, for example, at a rate of 2Hz / 1s (s is a second), or 1Hz / 1s (s is a second) for normal frequency reduction, the frequency reduction will continue until the compressor's phase current value I decreases to the level required to exit the frequency reduction protection. Simultaneously, under the corresponding operating conditions of the corresponding mode, the compressor's upper frequency limit will be reduced. This is to correct the upper limit frequency of the compressor downwards; This is the program's preset value, such as 5Hz~10Hz. At this point, it indicates that the compressor's phase current value I is relatively high, triggering the protection red line. Rapid frequency reduction is needed to decrease the overall current, system pressure, and component temperature rise, ensuring the motherboard's reliability. Simultaneously, to prevent repeated high-current surges to the motherboard, the compressor's upper frequency limit is adjusted downwards, reducing the maximum target frequency and lowering the overall current.

[0093] Step S462: If the corresponding outdoor ambient temperature T corresponds to the second preset value of frequency limiting - ≤ Compressor phase current value I < corresponding outdoor ambient temperature T for the mode corresponding to the first preset value of frequency reduction - If the compressor frequency P1 remains unchanged, it cannot be increased. The first and second preset frequency limiting values ​​are related to the model and rated cooling capacity of the inverter air conditioner; for example, the first preset frequency limiting value is 14A~16A, and the second preset frequency limiting value is 12.5A~14A. At this point, it indicates that the compressor's phase current value I is relatively high but still within an acceptable range. To ensure performance, the compressor frequency P1 can be maintained at its current frequency. Then, based on the changes in the operating phase current, it can be determined whether further intervention in the compressor's frequency increase or decrease is necessary. For example, based on the changes in the operating phase current, it can be determined whether further intervention in the compressor's frequency increase or decrease is necessary. Under the premise that the compressor frequency remains unchanged, if after a period of operation the phase current drops to the second preset frequency limiting value corresponding to the outdoor ambient temperature T of the corresponding mode... The compressor frequency can continue to increase. If the phase current continues to rise to the first preset value of frequency reduction corresponding to the outdoor ambient temperature T of the corresponding mode, the frequency can be reduced. If the above is true, then frequency reduction processing will be performed.

[0094] Step S463: If the compressor phase current value I < the corresponding outdoor ambient temperature T, the second preset value for frequency limiting is... If the compressor operates at the target frequency, it is permissible to increase the frequency. This indicates that the compressor's phase current value I is relatively small. To ensure performance, the compressor's frequency P1 is allowed to increase and operate at the target frequency.

[0095] In some implementations, step S220, based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, executes the first preset control logic of the frequency reduction protection mode of the compressor's phase current value to achieve frequency reduction protection of the compressor's phase current value. It also includes a control process of correcting the upper limit frequency of the compressor under the current operating mode after exiting the frequency reduction protection mode of the compressor's phase current value under the first preset control logic.

[0096] The following is combined with Figure 4 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention, in which the upper limit frequency of the compressor in the current operating mode is corrected after exiting the frequency reduction protection mode of the compressor phase current value under the first preset control logic. The flowchart further illustrates the specific process of correcting the upper limit frequency of the compressor in the current operating mode after exiting the frequency reduction protection mode of the compressor phase current value under the first preset control logic in step S220, including steps S410 to S440.

[0097] Step S410: After reducing the upper limit frequency of the compressor in the current operating mode by a set frequency value, the operating time of the compressor is re-timed to obtain the second cumulative operating time of the compressor; and within the second cumulative operating time of the compressor, the rate of change of the outdoor ambient temperature of the air conditioner is determined.

[0098] Step S420: Determine whether the second cumulative running time of the compressor is greater than or equal to the second preset running time, or whether the rate of change of the outdoor ambient temperature of the air conditioner is greater than or equal to the set temperature change rate. Then, return to the previous step to re-execute the first preset control logic or the second preset control logic of the frequency reduction protection mode of the compressor's phase current value based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger pipe temperature of the inverter air conditioner, so as to realize the frequency reduction protection of the compressor's phase current value.

[0099] Step S430: If yes, exit the frequency reduction protection mode of the compressor's phase current value and stop correcting the upper limit frequency of the compressor in the current operating mode. Then, return to the previous step to re-execute the first preset control logic or the second preset control logic of the frequency reduction protection mode of the compressor's phase current value based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the compressor's phase current value, the compressor's frequency, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger tube temperature of the inverter air conditioner, so as to realize the frequency reduction protection of the compressor's phase current value.

[0100] Step S440, otherwise, return, to re-execute the first preset control logic or the second preset control logic of the compressor phase current value frequency reduction protection mode based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger tube temperature of the inverter air conditioner, so as to realize the frequency reduction protection of the compressor phase current value.

[0101] Specifically, such as Figure 8 As shown, the method for controlling the upper frequency limit of a variable frequency air conditioner provided by the present invention further includes:

[0102] S18. After exiting the frequency reduction protection mode based on the phase current value, the upper limit of the compressor frequency is corrected according to the compressor frequency before the frequency reduction protection, and then step S19 is executed. When the whole machine enters the frequency reduction control, in order to avoid frequent fluctuations in the compressor frequency, the upper limit frequency of the compressor is corrected to reduce the fluctuation of the indoor ambient temperature and improve the user's comfort experience.

[0103] S19. Determine the correction of the upper limit of the compressor frequency, and then return to step S11.

[0104] In step S19, the system determines whether to exit the compressor frequency limit correction based on changes in ambient temperature and compressor running time, in order to avoid affecting the cooling and heating effects.

[0105] like Figure 11 and Figure 12 As shown, the method for controlling the upper frequency limit of a variable frequency air conditioner proposed in this invention further includes: in step S461, when the upper frequency limit of the compressor decreases... Then, the compressor's running time is timed. If the compressor's running time is ≥ the preset value t or the outdoor ambient temperature T, the compressor will be considered as a case in point. 外 Change value ≥ Then, the compressor's phase current value I will exit the frequency reduction protection mode and the frequency will be reduced. Correction, namely, reducing the upper limit frequency of the compressor. Otherwise, continue from step S46 to re-determine the compressor's phase current value. At this point, to ensure performance, after running for a period of time or when the outdoor ambient temperature changes significantly, first exit the determination of the compressor's phase current value I and frequency. Correct the error and reconfirm whether the overall phase current value I is still very high and whether the abnormal situation has disappeared.

[0106] Considering that frequent triggering of the phase current value frequency reduction protection will cause the compressor to frequently reduce its frequency, resulting in large fluctuations in room temperature, the solution of this invention reduces the compressor's upper limit frequency based on the preset upper limit frequency under the current ambient temperature conditions after the phase current value frequency reduction protection is deactivated. This avoids frequent frequency reduction caused by frequent triggering of the phase current value frequency reduction protection in a short period of time, which helps to reduce fluctuations in indoor ambient temperature and improve user comfort.

[0107] In this invention, by detecting the rate of change of system pressure (specifically, high system pressure) of the inverter air conditioner, the abnormal and normal conditions of rapid changes in system pressure and current (i.e., phase current value) of the whole unit are quickly determined: when the whole unit is in a normal condition, the frequency of the compressor is reduced and limited according to the frequency reduction current limit of the normal phase current value (i.e., the frequency reduction current limit of the phase current value and the frequency reduction current limit of the phase current value) to ensure the performance of the inverter air conditioner under extreme operating conditions; when the whole unit is in an abnormal condition, the frequency control of the compressor is intervened in advance to improve the reliability of the main board components of the inverter air conditioner; at the same time, when the whole unit enters the frequency reduction control, in order to avoid frequent fluctuations in the compressor frequency, the upper limit frequency of the compressor is corrected to reduce the fluctuation of indoor ambient temperature and improve the user's comfort experience.

[0108] In some embodiments, the upper limit frequency control parameter of the compressor in the current operating mode includes: the frequency limiting current value of the compressor in the current operating mode, the frequency reduction current value of the compressor in the current operating mode, the first frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, the second frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, and the upper limit frequency of the compressor in the current operating mode.

[0109] If the first cumulative running time of the compressor is less than the first preset running time, in steps S150 and S230, based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, the second preset control logic of the frequency reduction protection mode of the compressor phase current value is executed to realize the specific process of frequency reduction protection of the compressor phase current value. See the following exemplary description.

[0110] The following is combined with Figure 5 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention, which combines the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner to execute the second preset control logic of the phase current value of the compressor for frequency reduction protection mode. It further illustrates the wavelet packet analysis process of online monitoring in steps S150 and S230, which combines the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner to execute the second preset control logic of the phase current value of the compressor for frequency reduction protection mode, including steps S510 to S530.

[0111] Step S510: Determine whether the phase current value of the compressor is greater than or equal to the first frequency limiting current value. Wherein, the first frequency limiting current value is, for example, the outdoor ambient temperature T corresponding to the mode. 外 The corresponding first preset value for frequency reduction.

[0112] Step S520: If it is determined that the phase current value of the compressor is greater than or equal to the first frequency limiting current value, then the frequency of the compressor is reduced until the phase current value of the compressor is reduced to the point where the frequency reduction protection mode of the compressor's phase current value is exited; simultaneously, the upper limit frequency of the compressor in the current operating mode is reduced by a set frequency value to correct the upper limit frequency of the compressor. The set frequency value is as follows: .

[0113] Step S530: If it is determined that the phase current value of the compressor is less than the first frequency limiting current value, then:

[0114] First, if the phase current value of the compressor is greater than or equal to the second frequency limiting current value, the compressor frequency is kept at the current frequency and the compressor frequency is not allowed to increase. Then, the process returns to the previous state and, based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, the second preset control logic of the frequency reduction protection mode of the compressor phase current value is executed to realize the frequency reduction protection of the compressor phase current value.

[0115] Second, if the compressor's phase current value is less than the second frequency-limiting current value, the compressor's frequency is set to a preset target frequency, and the compressor's frequency is allowed to increase. Then, the process returns to the previous state to re-execute the second preset control logic for the compressor's phase current value frequency reduction protection mode, based on the compressor's upper limit frequency control parameters under the current operating mode, combined with the compressor's phase current value, the compressor's frequency, and the outdoor ambient temperature of the inverter air conditioner. This achieves frequency reduction protection for the compressor's phase current value. The second frequency-limiting current value corresponds to the outdoor ambient temperature T of the corresponding mode. 外 The corresponding second preset value for frequency reduction.

[0116] Specifically, such as Figure 11 and Figure 12 As shown, the method for controlling the upper frequency limit of a variable frequency air conditioner proposed in this invention further includes:

[0117] Step S51, if t is not satisfied 压 ≥Preset value condition, that is, if the compressor runs for t after startup 压 If the value is less than the preset value, then the following steps will be executed, such as steps S52 to S55.

[0118] Step S52: First determine whether the inverter air conditioner is in cooling mode or heating mode, so as to determine the upper limit frequency control value of the compressor under each operating condition based on the inverter air conditioner's operating mode.

[0119] Step S53: Compare the phase current value of the compressor with the preset value, and perform the following steps based on the comparison result, such as steps S531 to S533.

[0120] Step S531: If the compressor phase current value I ≥ the corresponding outdoor ambient temperature T 外 If the corresponding preset frequency reduction value is reached, the compressor frequency will be rapidly reduced until the phase current value drops to the level required to exit the frequency reduction protection. Simultaneously, under the corresponding operating conditions of the corresponding mode, the compressor's upper frequency limit will be reduced. This is to correct the upper limit frequency of the compressor downwards; This is the program's preset value, such as 5Hz~10Hz. At this point, it indicates that the compressor's phase current value I is relatively high, triggering the protection red line. Rapid frequency reduction is needed to decrease the overall current, system pressure, and component temperature rise, ensuring the motherboard's reliability. Simultaneously, to prevent repeated high-current surges to the motherboard, the compressor's upper frequency limit is adjusted downwards, reducing the maximum target frequency and lowering the overall current.

[0121] Step S532: If the second preset value for frequency limiting corresponding to the outdoor ambient temperature T of the corresponding mode is less than or equal to the compressor's phase current value I and less than the first preset value for frequency reduction corresponding to the outdoor ambient temperature T of the corresponding mode, then the compressor frequency remains at its current state and is not allowed to increase. This indicates that the compressor's phase current value I is relatively high but still within an acceptable range. To ensure performance, the compressor frequency can be maintained at its current frequency. Then, based on the changes in the operating phase current, it can be determined whether further intervention in the compressor's frequency increase or decrease is necessary.

[0122] Step S533: If the compressor's phase current value I is less than the second preset frequency limit value corresponding to the outdoor ambient temperature T of the corresponding mode, then the compressor's frequency will operate at the target frequency, and an increase is allowed. In this case, it indicates that the compressor's phase current value I is relatively small. To ensure performance, the compressor's frequency P1 is allowed to increase and operate at the target frequency.

[0123] Considering that the reliability limits for phase current values ​​differ under different modes and operating conditions, using the same set of limits would reduce the heating capacity at ultra-low temperatures or sacrifice reliability under high-temperature cooling conditions. Furthermore, using the same parameters for both normal and abnormal conditions would lower the phase current limits (i.e., the phase current frequency reduction protection value) to ensure the reliability of the mainboard components, thus reducing both ultra-low temperature heating capacity and high-temperature cooling capacity. The solution of this invention sets different phase current frequency reduction protection limits based on the maximum frequency requirements under different modes and operating conditions, as well as the temperature rise of components under ambient temperature conditions. This improves both the reliability of the mainboard components of the inverter air conditioner and its low-temperature heating capacity and high-temperature cooling capacity.

[0124] In some implementations, steps S150 and S230, based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, execute the second preset control logic of the frequency reduction protection mode of the compressor's phase current value to achieve frequency reduction protection of the compressor's phase current value. The steps also include: after exiting the frequency reduction protection mode of the compressor's phase current value under the second preset control logic, a control process is performed to correct the upper limit frequency of the compressor under the current operating mode.

[0125] The following is combined with Figure 6The flowchart shown is a schematic diagram of an embodiment of the method of the present invention, which corrects the upper limit frequency of the compressor in the current operating mode after exiting the frequency reduction protection mode of the compressor's phase current value under the second preset control logic. It further illustrates the specific process of correcting the upper limit frequency of the compressor in the current operating mode after exiting the frequency reduction protection mode of the compressor's phase current value under the second preset control logic in steps S150 and S230, including steps S610 to S640.

[0126] Step S610: After reducing the upper limit frequency of the compressor in the current operating mode by a set frequency value, the operating time of the compressor is re-timed to obtain the second cumulative operating time of the compressor; and within the second cumulative operating time of the compressor, the rate of change of the outdoor ambient temperature of the air conditioner is determined.

[0127] Step S620: Determine whether the second cumulative running time of the compressor is greater than or equal to the second preset running time, or whether the rate of change of the outdoor ambient temperature of the air conditioner is greater than or equal to the set temperature change rate.

[0128] Step S630: If yes, exit the frequency reduction protection mode of the compressor's phase current value and stop correcting the upper limit frequency of the compressor in the current operating mode. Then, return to the previous step to re-execute the second preset control logic of the frequency reduction protection mode of the compressor's phase current value based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the compressor's phase current value, the compressor's frequency, and the outdoor ambient temperature of the inverter air conditioner, so as to realize the frequency reduction protection of the compressor's phase current value.

[0129] Step S640, otherwise, return, to re-execute the second preset control logic of the compressor phase current value frequency reduction protection mode based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, so as to realize the frequency reduction protection of the compressor phase current value.

[0130] Specifically, such as Figure 11 and Figure 12 As shown, the method for controlling the upper frequency limit of a variable frequency air conditioner proposed in this invention further includes: in step S532, when the upper frequency limit of the compressor decreases... Then, the compressor's running time is timed. If the running time is greater than or equal to the preset value t or the outdoor ambient temperature T, the compressor will be considered as a compressor. 外 Change value ≥ Then the phase current value I and frequency of the compressor will be deactivated. Correction. Otherwise, continue from step S53 to re-determine the compressor's phase current value I. At this point, to ensure performance, after running for a period of time or when the ambient temperature changes significantly, first check the compressor's phase current value I and frequency. Correction. Reconfirm whether the overall phase current value is still very high and whether the abnormal situation has disappeared.

[0131] In this invention, on one hand, the phase current value of the inverter air conditioner is limited according to the operating mode and usage conditions, as well as normal and abnormal conditions. When the inverter air conditioner is operating in cooling or heating mode, the phase current limit gradually decreases as the outdoor ambient temperature rises; however, the phase current limit in heating mode is higher than that in cooling mode to ensure optimal performance for both low-temperature heating and high-temperature cooling. On the other hand, the system parameters of the inverter air conditioner (such as system pressure) are monitored, and the rate of change of the data is calculated based on the detected data. The rate of change is used to distinguish between abnormal and normal operation of the inverter air conditioner. If an abnormality occurs, the frequency limiting and reduction protection of the phase current value is intervened in advance to reduce the possibility of overshoot caused by untimely pressure response during compressor frequency reduction, thereby improving the reliability of the mainboard components of the inverter air conditioner. Finally, after exiting the frequency reduction protection of the phase current value and operating normally, the compressor's upper limit frequency is reduced according to the preset upper limit frequency under the current ambient temperature conditions. This avoids frequent frequency reduction caused by frequent entry into the phase current value frequency reduction protection in a short period of time, which helps to reduce fluctuations in the indoor ambient temperature and improve the user's comfort experience.

[0132] The technical solution of this embodiment, after the compressor of the inverter air conditioner starts, based on the length of the compressor's running time, and considering the operating mode of the inverter air conditioner, the compressor's phase current value, the compressor frequency, the outdoor ambient temperature, the outdoor heat exchanger tube temperature, and the indoor heat exchanger tube temperature, controls the compressor frequency according to preset frequency-limiting current and frequency-reducing current values ​​when the inverter air conditioner's operating conditions are within a preset normal range, thus ensuring the heat exchange capacity of the inverter air conditioner; when the inverter air conditioner's operating conditions are not within a preset normal range, the preset frequency-limiting current and frequency-reducing current values ​​are reduced in advance, and the frequency-limiting current is adjusted according to the reduced phase current value. The compressor frequency is controlled by the limiting current value and the frequency reduction current value of the phase current. Thus, by monitoring the operation of the inverter air conditioner, when the operation of the inverter air conditioner is within the preset normal conditions, the compressor frequency is controlled according to the preset limiting current value and the frequency reduction current value of the phase current, ensuring the heat exchange capacity of the inverter air conditioner; when the operation of the inverter air conditioner is not within the preset normal conditions, the preset limiting current value and the frequency reduction current value of the phase current are reduced in advance, and the compressor frequency is controlled according to the reduced limiting current value and the frequency reduction current value of the phase current, avoiding overshoot caused by untimely pressure response during compressor frequency reduction, and ensuring the operational reliability of the inverter air conditioner.

[0133] According to an embodiment of the present invention, a control device for a variable frequency air conditioner corresponding to a control method for a variable frequency air conditioner is also provided. See also Figure 7 The diagram shows a structural schematic of an embodiment of the device of the present invention. The variable frequency air conditioner includes a compressor, an outdoor heat exchanger, and an indoor heat exchanger; the control device of the variable frequency air conditioner includes: an acquisition unit 102 and a control unit 104.

[0134] The control unit 104 is configured to time the compressor's running time after it starts, thus obtaining a first cumulative running time. The specific functions and processing of this control unit 104 are described in step S110.

[0135] The control unit 104 is further configured to determine the current operating mode of the inverter air conditioner; and in the current operating mode of the inverter air conditioner, determine the upper limit frequency control parameter of the compressor of the inverter air conditioner, denoted as the upper limit frequency control parameter of the compressor in the current operating mode; the current operating mode of the inverter air conditioner is either heating mode or cooling mode. For the specific functions and processing of the control unit 104, please refer to step S120.

[0136] The acquisition unit 102 is configured to acquire the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger tube temperature of the inverter air conditioner. In cooling mode, the outdoor heat exchanger tube temperature of the inverter air conditioner is the condensing temperature T. 冷 In heating mode, the outdoor heat exchanger tube temperature of the inverter air conditioner is the evaporation temperature T. 蒸 The specific functions and processing of the acquisition unit 102 are described in step S130.

[0137] The control unit 104 is further configured to, when the first cumulative operating time of the compressor is greater than or equal to a first preset operating time, execute either a first preset control logic or a second preset control logic for a frequency reduction protection mode of the compressor's phase current value, based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the compressor's phase current value, the compressor's frequency, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger pipe temperature of the inverter air conditioner, to achieve frequency reduction protection of the compressor's phase current value. The first preset operating time is, for example, time t. The specific functions and processing of this control unit 104 are further described in step S140.

[0138] The control unit 104 is further configured to, when the first cumulative operating time of the compressor is less than the first preset operating time, execute a second preset control logic for a frequency reduction protection mode of the compressor's phase current value, based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, to achieve frequency reduction protection of the compressor's phase current value. The specific functions and processing of this control unit 104 are further described in step S150.

[0139] Specifically, Figure 8 This is a schematic diagram of the control logic of one embodiment of a method for controlling the upper frequency limit of a variable frequency air conditioner. Figure 8 As shown, the present invention provides a method for controlling the upper frequency limit of a variable frequency air conditioner, comprising:

[0140] S10. After the inverter air conditioner is powered on and turned on, obtain the running time of the compressor after it starts, and then execute step S11.

[0141] S11. Determine the length of the compressor's running time after it is turned on, so as to make further determinations when distinguishing control schemes based on the length of the compressor's running time after it is turned on. Then, proceed to step S12.

[0142] S12. Determine whether the phase current value of the compressor is controlled according to the normal limit or whether it is necessary to add a judgment on abnormal conditions, and then proceed to step S13.

[0143] S13. Obtain the operating mode and outdoor ambient temperature of the inverter air conditioner. Based on the operating mode and outdoor ambient temperature of the inverter air conditioner, determine the limit value of the compressor phase current. Then, execute step S14.

[0144] S14. Obtain the evaporator temperature and condenser temperature of the inverter air conditioner, and obtain the compressor frequency and phase current value, then execute step S15.

[0145] S15. Determine whether the inverter air conditioner has entered the phase current value reduction protection mode: If the inverter air conditioner's control system is in normal condition, it is only necessary to compare the phase current value with the preset value and adjust the compressor frequency; if the inverter air conditioner's control system is in abnormal condition, it is necessary to lower the limit of the phase current value on the basis of normal condition in order to achieve the purpose of intervening in the compressor frequency in advance. Adjust the compressor frequency control according to the updated phase current value limit, and then execute step S16.

[0146] S16. Control the compressor frequency based on the frequency limiting protection of the phase current value and the frequency reduction current value, and then execute step S17.

[0147] S17. Determine whether the inverter air conditioner has exited the frequency reduction protection mode of the phase current value, and then execute step S18.

[0148] Figure 9 The diagram shows the curve of the phase current limit of a variable frequency air conditioner (i.e., the phase current limit) changing with the outdoor ambient temperature. (a) is a diagram of the curve of the phase current limit of a variable frequency air conditioner changing with the outdoor ambient temperature in heating mode, and (b) is a diagram of the curve of the phase current limit of a variable frequency air conditioner changing with the outdoor ambient temperature in cooling mode. Figure 9 The correlation between the phase current limit of the variable frequency air conditioner control system and the outdoor ambient temperature in different modes is presented. Specifically, when the outdoor ambient temperature is low, the temperature rise of the main board components is low, and the allowable phase current limit can be higher. As the outdoor ambient temperature increases, the phase current limit gradually decreases.

[0149] See Figure 9 In the example shown, since the outdoor ambient temperature allowed in heating mode is lower than that allowed in cooling mode, the limit for the maximum phase current value in heating mode is higher than that in cooling mode.

[0150] Figure 10 This is a schematic diagram of the control logic of an embodiment of a step-by-step control method for adjusting the phase current value of a variable frequency air conditioner. Figure 10 A step-by-step control scheme is presented for the control system of a variable frequency air conditioner when controlling the phase current value. For example... Figure 10 As shown, the step-by-step control method for the phase current value of a variable frequency air conditioner proposed in this invention includes:

[0151] Step 21: When the phase current value gradually increases, if the preset phase current value is reached, the compressor frequency is allowed to increase slowly.

[0152] Step 22: When the phase current value continues to rise and reaches the preset phase current value limit current value, the compressor frequency is not allowed to continue to rise.

[0153] Step 23: When the phase current value continues to rise and reaches the preset phase current value for frequency reduction, the compressor frequency should be rapidly reduced.

[0154] Among them, the preset phase current value is the gradual rise current value < the preset phase current value is the frequency limiting current value < the preset phase current value is the frequency reduction current value.

[0155] The present invention provides a solution for controlling the upper limit of frequency in a variable frequency air conditioner. By detecting the rate of change of system pressure (specifically, high system pressure) in the variable frequency air conditioner, it quickly determines abnormal and normal conditions of rapid changes in system pressure and current (i.e., phase current value). When the unit is in a normal condition, the compressor frequency is reduced and limited according to the frequency reduction current limit of the normal phase current value (i.e., the frequency limiting current limit of the phase current value and the frequency reduction current limit of the phase current value), ensuring the performance of the variable frequency air conditioner under extreme operating conditions. When the unit is in an abnormal condition, the frequency control of the compressor is intervened in advance to improve the reliability of the main board components of the variable frequency air conditioner.

[0156] In some embodiments, when the first cumulative operating time of the compressor is greater than or equal to a first preset operating time, the control unit 104, based on the upper limit frequency control parameters of the compressor under the current operating mode, and in combination with the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger pipe temperature of the inverter air conditioner, executes a first preset control logic or a second preset control logic for a frequency reduction protection mode of the compressor's phase current value, to achieve frequency reduction protection of the compressor's phase current value, including:

[0157] The control unit 104 is further configured to determine the rate of change of the outdoor heat exchanger pipe temperature of the inverter air conditioner within a continuously set time period; and to determine whether the rate of change of the outdoor heat exchanger pipe temperature of the inverter air conditioner is greater than or equal to a set pipe temperature change rate. The set time period is, for example, 30 seconds, and the set pipe temperature change rate is, for example, a third preset value. In cooling mode, the rate of change of the outdoor heat exchanger pipe temperature of the inverter air conditioner is (T... 冷 '-T 冷) / T 冷 The rate of change of the outdoor heat exchanger pipe temperature of the inverter air conditioner in heating mode is (T 蒸 '-T 蒸 ) / T 蒸 :(T 冷 '-T 冷 ) / T 冷 For details on the specific functions and processing of the control unit 104, please refer to step S210.

[0158] The control unit 104 is further configured to, if it is determined that the rate of change of the outdoor heat exchanger pipe temperature of the inverter air conditioner is greater than or equal to a set pipe temperature change rate, then, based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, execute the first preset control logic of the frequency reduction protection mode for the phase current value of the compressor, so as to realize the frequency reduction protection for the phase current value of the compressor. The specific functions and processing of this control unit 104 are further described in step S220.

[0159] The control unit 104 is further configured to, if it is determined that the rate of change of the outdoor heat exchanger pipe temperature of the inverter air conditioner is less than a set pipe temperature change rate, then, based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, execute the second preset control logic of the frequency reduction protection mode for the phase current value of the compressor, so as to realize the frequency reduction protection for the phase current value of the compressor. The specific functions and processing of this control unit 104 are further described in step S230.

[0160] Specifically, Figure 11 Detailed control logic diagram of an embodiment of a method for controlling the upper frequency limit of an inverter air conditioner Figure 1 , Figure 12 Detailed control logic diagram of an embodiment of a method for controlling the upper frequency limit of an inverter air conditioner Figure 2 . Figure 11 and Figure 12 A detailed control logic operation reference example for a variable frequency air conditioner control system is provided. For example... Figure 11 and Figure 12 As shown, the method for controlling the upper frequency limit of a variable frequency air conditioner proposed in this invention specifically includes:

[0161] Step S31: The inverter air conditioner is turned on, and the compressor changes from the off state to the on state. Then, step S32 is executed.

[0162] Step S32: Set the compressor running time t after startup. 压Timing is initiated, followed by step S33. During the compressor start-up phase, the compressor frequency gradually increases from 0Hz to the target frequency. During this process, the system high pressure of the compressor changes drastically, and the phase current value of the compressor increases rapidly; however, this is normal. Therefore, during the start-up phase, only the compressor's running time t after startup is recorded. 压 The timer is set, but the compressor's operation is not judged to be normal or abnormal during the startup phase.

[0163] Step S33: Determine whether the compressor starts running for the specified time t. 压 ≥Preset value: If yes, proceed to step S41; otherwise, proceed to step S51. In step S33, first determine the continuous running time after the compressor starts, i.e., the running time t after the compressor starts. 压 The running time t after the compressor starts 压 Determine which control scheme is used to control the phase current value of the compressor.

[0164] Step S41: If the compressor runs for t days after startup... 压 If the value is greater than or equal to the preset value, then the following steps will be executed, such as steps S42 to S46.

[0165] Step S42: First determine whether the inverter air conditioner is in cooling mode or heating mode, so as to determine the upper limit frequency control value of the compressor under each operating condition based on the inverter air conditioner's operating mode.

[0166] Step S43: Obtain the compressor phase current value I, compressor frequency P1, and outdoor ambient temperature T. 外 Evaporation temperature T 蒸 Condensation temperature T 冷 Data. The data obtained here is used to prepare for subsequent calculations and judgments.

[0167] Step S44, in cooling mode, continuously detect for a certain period of time, for example, 30 seconds. If the initial detection value T... 冷 'Compared with the last detection value T 冷 The difference satisfies: (T) 冷 '-T 冷 ) / T 冷 If the value is greater than or equal to the third preset value, then proceed according to step S45; otherwise, proceed according to step t. 压 The program execution with the preset value is to execute the program according to step S51.

[0168] In heating mode, continuous monitoring is performed for a certain period of time, for example, 30 seconds. If the initial detection value T... 蒸 'Compared with the last detection value T 蒸 The difference satisfies: (T) 蒸 '-T蒸 ) / T 蒸 If the value is greater than or equal to the third preset value, then proceed according to step S45; otherwise, proceed according to step t. 压 The program execution with the preset value is to execute the program according to step S51.

[0169] If this standard is met, it indicates that the system pressure of the inverter air conditioner and the phase current value I of the compressor are changing rapidly, and the whole unit is in an abnormal state. It is necessary to intervene in advance by comparing the phase current value I of the compressor with the preset value and adjusting the frequency P1 of the compressor in advance.

[0170] Considering that when the system pressure of a variable frequency air conditioner changes rapidly, the phase current value of the compressor motor increases too quickly, and when the frequency reduction protection of the phase current value is triggered, the compressor's frequency reduction process may result in overshoot due to untimely pressure response. The solution of this invention detects the system parameters (such as system pressure) of the variable frequency air conditioner, calculates the rate of change of the detected data (such as system pressure), and distinguishes between abnormal and normal operation of the variable frequency air conditioner based on the rate of change. If an abnormality occurs, the frequency limiting and frequency reduction protection of the phase current value intervenes in advance, reducing the possibility of overshoot caused by untimely pressure response during compressor frequency reduction, and improving the reliability of the mainboard components of the variable frequency air conditioner.

[0171] In the solution of this invention, by calculating the rate of change of the system pressure of the variable frequency air conditioner, it is possible to distinguish whether the control system of the variable frequency air conditioner is in a normal or abnormal state: if it is in a normal state, it is controlled according to the originally set phase current protection value; if it is in an abnormal state, the frequency limiting current value and the frequency reduction current value of the phase current value are reduced to intervene in the compressor frequency in advance, so as to achieve the purpose of early protection and improve the reliability of the main board components of the variable frequency air conditioner.

[0172] In some embodiments, the upper limit frequency control parameter of the compressor in the current operating mode includes: the frequency limiting current value of the compressor in the current operating mode, the frequency reduction current value of the compressor in the current operating mode, the first frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, the second frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, and the upper limit frequency of the compressor in the current operating mode.

[0173] The control unit 104, based on the upper limit frequency control parameters of the compressor under the current operating mode, and in conjunction with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, executes the first preset control logic of the frequency reduction protection mode for the phase current value of the compressor to achieve frequency reduction protection for the phase current value of the compressor, including:

[0174] The control unit 104 is further configured to reduce the frequency-limiting current value of the compressor in the current operating mode by a set current value, and to reduce the frequency-reducing current value of the compressor in the current operating mode by a set current value. The set current value is as follows: For details on the specific functions and processing of the control unit 104, please refer to step S310.

[0175] The control unit 104 is further configured to determine whether the phase current value of the compressor is greater than or equal to the difference between the first frequency-limiting current value and the set current value. The first frequency-limiting current value is, for example, the outdoor ambient temperature T corresponding to the mode. 外 The corresponding first preset value for frequency reduction. For the specific functions and processing of this control unit 104, please refer to step S320.

[0176] The control unit 104 is further configured to, if it is determined that the phase current value of the compressor is greater than or equal to the difference between the first frequency-limiting current value and the set current value, reduce the frequency of the compressor until the phase current value of the compressor is reduced to the point where it exits the frequency reduction protection mode of the compressor's phase current value; simultaneously, it reduces the upper limit frequency of the compressor in the current operating mode by a set frequency value to correct the upper limit frequency of the compressor. The set frequency value is as follows: For details on the specific functions and processing of the control unit 104, please refer to step S330.

[0177] The control unit 104 is further configured to, if it is determined that the phase current value of the compressor is less than the difference between the first frequency limiting current value and the set current value, then:

[0178] First, the control unit 104 is specifically configured to, when the phase current value of the compressor is greater than or equal to the difference between the second frequency limiting current value and the set current value, maintain the current frequency of the compressor and not allow the frequency of the compressor to increase. Then, it returns to execute the first preset control logic of the frequency reduction protection mode of the compressor phase current value based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, so as to realize the frequency reduction protection of the compressor phase current value.

[0179] Second, the control unit 104 is specifically configured to, when the phase current value of the compressor is less than the difference between the second frequency-limiting current value and the set current value, set the compressor frequency to a preset target frequency and allow the compressor frequency to increase. Then, it returns to the previous state to re-execute the first preset control logic for the frequency reduction protection mode of the compressor's phase current value based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the compressor's phase current value, the compressor frequency, and the outdoor ambient temperature of the inverter air conditioner, to achieve frequency reduction protection for the compressor's phase current value. The second frequency-limiting current value corresponds to the outdoor ambient temperature T of the corresponding mode. 外 The corresponding second preset value for frequency reduction. For the specific functions and processing of this control unit 104, please refer to step S340.

[0180] Specifically, such as Figure 11 and Figure 12 As shown, the method for controlling the upper frequency limit of a variable frequency air conditioner proposed in this invention further includes:

[0181] Step S45: Corresponding operating conditions for different operating modes: Reduce the current value of the compressor's frequency limiting current value and frequency reducing current value. The reduction value is... Then, proceed to step S46; where, These are the preset values ​​for the program. At this point, the compressor frequency is intervened in advance by reducing the compressor's frequency limiting current value and frequency reduction current value.

[0182] Step S46: Compare the phase current value I of the compressor with the preset value, and perform the following steps according to the comparison result, such as steps S461 to S463.

[0183] Step S461: If the compressor phase current value I ≥ the outdoor ambient temperature T of the corresponding mode 外 The corresponding first preset value for frequency reduction - If this happens, the compressor frequency P1 will be rapidly reduced until the compressor's phase current value I drops to a level that triggers the frequency reduction protection to exit phase current protection. Simultaneously, under the corresponding operating conditions of the corresponding mode, the compressor's upper frequency limit will be reduced. This is to correct the upper limit frequency of the compressor downwards; This is the program's preset value. At this point, it indicates that the compressor's phase current value I is relatively high, triggering the protection red line. Rapid frequency reduction is needed to lower the overall current, system pressure, and component temperature rise, ensuring the motherboard's reliability. Simultaneously, to prevent repeated high-current surges to the motherboard, the compressor's upper frequency limit is adjusted downwards, reducing the maximum target frequency and lowering the overall current.

[0184] Step S462: If the corresponding outdoor ambient temperature T corresponds to the second preset value of frequency limiting - ≤ Compressor phase current value I < corresponding outdoor ambient temperature T for the mode corresponding to the first preset value of frequency reduction - If the compressor frequency P1 remains unchanged, it is not allowed to increase. This indicates that the compressor's phase current value I is relatively high but still within an acceptable range. To ensure performance, the compressor frequency P1 can be maintained at its current level. Then, based on the changes in the operating phase current, it can be determined whether further intervention in the compressor's frequency increase or decrease is necessary.

[0185] Step S463: If the compressor phase current value I < the corresponding outdoor ambient temperature T, the second preset value for frequency limiting is... If the compressor operates at the target frequency, it is permissible to increase the frequency. This indicates that the compressor's phase current value I is relatively small. To ensure performance, the compressor's frequency P1 is allowed to increase and operate at the target frequency.

[0186] In some embodiments, the control unit 104, based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, executes a first preset control logic for a frequency reduction protection mode of the compressor's phase current value to achieve frequency reduction protection of the compressor's phase current value. The control unit also includes a control process for correcting the upper limit frequency of the compressor in the current operating mode after exiting the frequency reduction protection mode of the compressor's phase current value under the first preset control logic, as detailed below:

[0187] The control unit 104 is further configured to, after reducing the upper limit frequency of the compressor in the current operating mode by a set frequency value, re-time the compressor's operating time to obtain a second cumulative operating time of the compressor; and determine the rate of change of the outdoor ambient temperature of the air conditioner within the second cumulative operating time of the compressor. The specific functions and processing of this control unit 104 are further described in step S410.

[0188] The control unit 104 is further configured to determine whether the second cumulative operating time of the compressor is greater than or equal to the second preset operating time, or whether the rate of change of the outdoor ambient temperature of the air conditioner is greater than or equal to the set temperature change rate. Then, it returns to the previous state and, based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger pipe temperature of the inverter air conditioner, executes the first or second preset control logic of the frequency reduction protection mode for the compressor's phase current value to achieve frequency reduction protection for the compressor's phase current value. The specific functions and processing of this control unit 104 are also described in step S420.

[0189] Specifically, the control unit 104 is further configured to, if so, exit the frequency reduction protection mode for the compressor's phase current value and stop correcting the upper limit frequency of the compressor in the current operating mode. Then, it returns to the previous state and, based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the compressor's phase current value, the compressor's frequency, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger pipe temperature of the inverter air conditioner, execute either the first preset control logic or the second preset control logic for the frequency reduction protection mode of the compressor's phase current value to achieve frequency reduction protection for the compressor's phase current value. The specific functions and processing of this control unit 104 are further described in step S430.

[0190] Specifically, the control unit 104 is further configured to otherwise return to the previous state, and re-execute either the first or second preset control logic for the compressor's phase current value frequency reduction protection mode based on the compressor's upper limit frequency control parameters under the current operating mode, combined with the compressor's phase current value, the compressor's frequency, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger pipe temperature of the inverter air conditioner, to achieve frequency reduction protection for the compressor's phase current value. The specific functions and processing of this control unit 104 are further described in step S440.

[0191] Specifically, such as Figure 8 As shown, the method for controlling the upper frequency limit of a variable frequency air conditioner provided by the present invention further includes:

[0192] S18. After exiting the frequency reduction protection mode based on the phase current value, the upper limit of the compressor frequency is corrected according to the compressor frequency before the frequency reduction protection, and then step S19 is executed. When the whole machine enters the frequency reduction control, in order to avoid frequent fluctuations in the compressor frequency, the upper limit frequency of the compressor is corrected to reduce the fluctuation of the indoor ambient temperature and improve the user's comfort experience.

[0193] S19. Determine the correction of the upper limit of the compressor frequency, and then return to step S11.

[0194] In step S19, the system determines whether to exit the compressor frequency limit correction based on changes in ambient temperature and compressor running time, in order to avoid affecting the cooling and heating effects.

[0195] like Figure 11 and Figure 12 As shown, the method for controlling the upper frequency limit of a variable frequency air conditioner proposed in this invention further includes: in step S461, when the upper frequency limit of the compressor decreases... Then, the compressor's running time is timed. If the compressor's running time is ≥ the preset value t or the outdoor ambient temperature T, the compressor will be considered as a case in point. 外 Change value ≥ Then, the compressor's phase current value I will exit the frequency reduction protection mode and the frequency will be reduced. Correction. Otherwise, continue from step S46 to re-determine the compressor's phase current value. At this point, to ensure performance, after running for a period of time or when the outdoor ambient temperature changes significantly, first check the compressor's phase current value I and frequency. Correct the error and reconfirm whether the overall phase current value I is still very high and whether the abnormal situation has disappeared.

[0196] Considering that frequent triggering of the phase current value frequency reduction protection will cause the compressor to frequently reduce its frequency, resulting in large fluctuations in room temperature, the solution of this invention reduces the compressor's upper limit frequency based on the preset upper limit frequency under the current ambient temperature conditions after the phase current value frequency reduction protection is deactivated. This avoids frequent frequency reduction caused by frequent triggering of the phase current value frequency reduction protection in a short period of time, which helps to reduce fluctuations in indoor ambient temperature and improve user comfort.

[0197] In this invention, by detecting the rate of change of system pressure (specifically, high system pressure) of the inverter air conditioner, the abnormal and normal conditions of rapid changes in system pressure and current (i.e., phase current value) of the whole unit are quickly determined: when the whole unit is in a normal condition, the frequency of the compressor is reduced and limited according to the frequency reduction current limit of the normal phase current value (i.e., the frequency reduction current limit of the phase current value and the frequency reduction current limit of the phase current value) to ensure the performance of the inverter air conditioner under extreme operating conditions; when the whole unit is in an abnormal condition, the frequency control of the compressor is intervened in advance to improve the reliability of the main board components of the inverter air conditioner; at the same time, when the whole unit enters the frequency reduction control, in order to avoid frequent fluctuations in the compressor frequency, the upper limit frequency of the compressor is corrected to reduce the fluctuation of indoor ambient temperature and improve the user's comfort experience.

[0198] In some embodiments, the upper limit frequency control parameter of the compressor in the current operating mode includes: the frequency limiting current value of the compressor in the current operating mode, the frequency reduction current value of the compressor in the current operating mode, the first frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, the second frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, and the upper limit frequency of the compressor in the current operating mode.

[0199] When the first cumulative operating time of the compressor is less than the first preset operating time, in steps S150 and S230, the control unit 104, based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, executes the second preset control logic of the frequency reduction protection mode for the phase current value of the compressor to achieve frequency reduction protection for the phase current value of the compressor, including:

[0200] The control unit 104 is further configured to determine whether the phase current value of the compressor is greater than or equal to the first frequency limiting current value. The first frequency limiting current value is, for example, the outdoor ambient temperature T corresponding to the mode. 外 The corresponding first preset value for frequency reduction. For the specific functions and processing of this control unit 104, please refer to step S510.

[0201] The control unit 104 is further configured to, if it is determined that the phase current value of the compressor is greater than or equal to the first frequency limiting current value, reduce the frequency of the compressor until the phase current value of the compressor is reduced to the point where it exits the frequency reduction protection mode of the compressor's phase current value; simultaneously, it lowers the upper limit frequency of the compressor in the current operating mode by a set frequency value to correct the upper limit frequency of the compressor. The set frequency value is as follows: For details on the specific functions and processing of the control unit 104, please refer to step S520.

[0202] The control unit 104 is further configured to, if it is determined that the phase current value of the compressor is less than the first frequency limiting current value, then:

[0203] First, the control unit 104 is specifically configured to, when the phase current value of the compressor is greater than or equal to the second frequency limiting current value, maintain the current frequency of the compressor and not allow the compressor frequency to increase. Then, it returns to execute the second preset control logic of the frequency reduction protection mode of the compressor phase current value based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, so as to realize the frequency reduction protection of the compressor phase current value.

[0204] Second, the control unit 104 is specifically configured to, when the phase current value of the compressor is less than the second frequency limiting current value, set the compressor frequency to a preset target frequency and allow the compressor frequency to increase. Then, it returns to the previous state to re-execute the second preset control logic for the frequency reduction protection mode of the compressor's phase current value based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the compressor's phase current value, the compressor frequency, and the outdoor ambient temperature of the inverter air conditioner, to achieve frequency reduction protection for the compressor's phase current value. The second frequency limiting current value corresponds to the outdoor ambient temperature T of the corresponding mode. 外 The corresponding second preset value for frequency reduction. For the specific functions and processing of this control unit 104, please refer to step S530.

[0205] Specifically, such as Figure 11 and Figure 12 As shown, the method for controlling the upper frequency limit of a variable frequency air conditioner proposed in this invention further includes:

[0206] Step S51, if t is not satisfied 压 ≥Preset value condition, that is, if the compressor runs for t after startup 压 If the value is less than the preset value, then the following steps will be executed, such as steps S52 to S55.

[0207] Step S52: First determine whether the inverter air conditioner is in cooling mode or heating mode, so as to determine the upper limit frequency control value of the compressor under each operating condition based on the inverter air conditioner's operating mode.

[0208] Step S53: Compare the phase current value of the compressor with the preset value, and perform the following steps based on the comparison result, such as steps S531 to S533.

[0209] Step S531: If the compressor phase current value I ≥ the corresponding outdoor ambient temperature T 外If the corresponding preset frequency reduction value is reached, the compressor frequency will be rapidly reduced until the phase current value drops to the level required to exit the frequency reduction protection. Simultaneously, under the corresponding operating conditions of the corresponding mode, the compressor's upper frequency limit will be reduced. This is to correct the upper limit frequency of the compressor downwards; This is the program's preset value. At this point, it indicates that the compressor's phase current value I is relatively high, triggering the protection red line. Rapid frequency reduction is needed to lower the overall current, system pressure, and component temperature rise, ensuring the motherboard's reliability. Simultaneously, to prevent repeated high-current surges to the motherboard, the compressor's upper frequency limit is adjusted downwards, reducing the maximum target frequency and lowering the overall current.

[0210] Step S532: If the second preset value for frequency limiting corresponding to the outdoor ambient temperature T of the corresponding mode is less than or equal to the compressor's phase current value I and less than the first preset value for frequency reduction corresponding to the outdoor ambient temperature T of the corresponding mode, then the compressor frequency remains at its current state and is not allowed to increase. This indicates that the compressor's phase current value I is relatively high but still within an acceptable range. To ensure performance, the compressor frequency can be maintained at its current frequency. Then, based on the changes in the operating phase current, it can be determined whether further intervention in the compressor's frequency increase or decrease is necessary.

[0211] Step S533: If the compressor's phase current value I is less than the second preset frequency limit value corresponding to the outdoor ambient temperature T of the corresponding mode, then the compressor's frequency will operate at the target frequency, and an increase is allowed. In this case, it indicates that the compressor's phase current value I is relatively small. To ensure performance, the compressor's frequency P1 is allowed to increase and operate at the target frequency.

[0212] Considering that the reliability limits for phase current values ​​differ under different modes and operating conditions, using the same set of limits would reduce the heating capacity at ultra-low temperatures or sacrifice reliability under high-temperature cooling conditions. Furthermore, using the same parameters for both normal and abnormal conditions would lower the phase current limits (i.e., the phase current frequency reduction protection value) to ensure the reliability of the mainboard components, thus reducing both ultra-low temperature heating capacity and high-temperature cooling capacity. The solution of this invention sets different phase current frequency reduction protection limits based on the maximum frequency requirements under different modes and operating conditions, as well as the temperature rise of components under ambient temperature conditions. This improves both the reliability of the mainboard components of the inverter air conditioner and its low-temperature heating capacity and high-temperature cooling capacity.

[0213] In some embodiments, the control unit 104, based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, executes a second preset control logic for a frequency reduction protection mode of the compressor's phase current value to achieve frequency reduction protection of the compressor's phase current value. The control unit also includes a control process for correcting the upper limit frequency of the compressor in the current operating mode after exiting the frequency reduction protection mode of the compressor's phase current value under the second preset control logic, as detailed below:

[0214] The control unit 104 is further configured to, after reducing the upper limit frequency of the compressor in the current operating mode by a set frequency value, re-time the compressor's operating time to obtain a second cumulative operating time of the compressor; and determine the rate of change of the outdoor ambient temperature of the air conditioner within the second cumulative operating time of the compressor. The specific functions and processing of this control unit 104 are further described in step S610.

[0215] The control unit 104 is further configured to determine whether the second cumulative operating time of the compressor is greater than or equal to the second preset operating time, or whether the rate of change of the outdoor ambient temperature of the air conditioner is greater than or equal to the set temperature rate of change. The specific functions and processing of the control unit 104 are further described in step S620.

[0216] Specifically, the control unit 104 is further configured to, if so, exit the frequency reduction protection mode for the compressor's phase current value and stop correcting the upper limit frequency of the compressor in the current operating mode. Then, it returns to the previous state and, based on the upper limit frequency control parameters of the compressor in the current operating mode, combined with the compressor's phase current value, the compressor's frequency, and the outdoor ambient temperature of the inverter air conditioner, execute the second preset control logic for the frequency reduction protection mode of the compressor's phase current value to achieve frequency reduction protection for the compressor's phase current value. The specific functions and processing of this control unit 104 are further described in step S630.

[0217] Specifically, the control unit 104 is further configured to otherwise return to the previous state, and re-execute the second preset control logic of the compressor's phase current value frequency reduction protection mode based on the compressor's upper limit frequency control parameters under the current operating mode, combined with the compressor's phase current value, the compressor's frequency, and the outdoor ambient temperature of the inverter air conditioner, to achieve frequency reduction protection for the compressor's phase current value. The specific functions and processing of this control unit 104 are further described in step S640.

[0218] Specifically, such as Figure 11 and Figure 12As shown, the method for controlling the upper frequency limit of a variable frequency air conditioner proposed in this invention further includes: in step S532, when the upper frequency limit of the compressor decreases... Then, the compressor's running time is timed. If the running time is greater than or equal to the preset value t or the outdoor ambient temperature T, the compressor will be considered as the compressor is running. 外 Change value ≥ Then the phase current value I and frequency of the compressor will be deactivated. Correction. Otherwise, continue from step S53 to re-determine the compressor's phase current value I. At this point, to ensure performance, after running for a period of time or when the ambient temperature changes significantly, first check the compressor's phase current value I and frequency. Correction. Reconfirm whether the overall phase current value is still very high and whether the abnormal situation has disappeared.

[0219] In this invention, on one hand, the phase current value of the inverter air conditioner is limited according to the operating mode and usage conditions, as well as normal and abnormal conditions. When the inverter air conditioner is operating in cooling or heating mode, the phase current limit gradually decreases as the outdoor ambient temperature rises; however, the phase current limit in heating mode is higher than that in cooling mode to ensure optimal performance for both low-temperature heating and high-temperature cooling. On the other hand, the system parameters of the inverter air conditioner (such as system pressure) are monitored, and the rate of change of the data is calculated based on the detected data. The rate of change is used to distinguish between abnormal and normal operation of the inverter air conditioner. If an abnormality occurs, the frequency limiting and reduction protection of the phase current value is intervened in advance to reduce the possibility of overshoot caused by untimely pressure response during compressor frequency reduction, thereby improving the reliability of the mainboard components of the inverter air conditioner. Finally, after exiting the frequency reduction protection of the phase current value and operating normally, the compressor's upper limit frequency is reduced according to the preset upper limit frequency under the current ambient temperature conditions. This avoids frequent frequency reduction caused by frequent entry into the phase current value frequency reduction protection in a short period of time, which helps to reduce fluctuations in the indoor ambient temperature and improve the user's comfort experience.

[0220] 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.

[0221] By employing the technical solution of this invention, after the compressor of a variable frequency air conditioner starts, based on the length of the compressor's running time after startup, and considering the operating mode of the variable frequency air conditioner, the compressor's phase current value, the compressor frequency, the outdoor ambient temperature, the outdoor heat exchanger tube temperature, and the indoor heat exchanger tube temperature, when the operation of the variable frequency air conditioner is within a preset normal condition, the compressor frequency is controlled according to the preset phase current value's frequency limiting current value and frequency reducing current value, ensuring the heat exchange capacity of the variable frequency air conditioner; when the operation of the variable frequency air conditioner is not within a preset normal condition, the preset phase current value's frequency limiting current value and frequency reducing current value are reduced in advance, and the compressor frequency is controlled according to the reduced phase current value's frequency limiting current value and frequency reducing current value. In abnormal situations, the frequency limiting and frequency reducing protection of the phase current value intervenes in advance, reducing the possibility of overshoot caused by untimely pressure response during compressor frequency reduction, and improving the reliability of the main board components of the variable frequency air conditioner.

[0222] According to an embodiment of the present invention, a variable frequency air conditioner corresponding to a control device for a variable frequency air conditioner is also provided. This variable frequency air conditioner may include the control device for a variable frequency air conditioner described above.

[0223] Since the processing and functions implemented by the variable frequency air conditioner in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned device, 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.

[0224] By employing the technical solution of this invention, after the compressor of the inverter air conditioner starts, based on the length of the compressor's running time after startup, and considering the operating mode of the inverter air conditioner, the compressor's phase current value, the compressor frequency, the outdoor ambient temperature, the outdoor heat exchanger tube temperature, and the indoor heat exchanger tube temperature, when the inverter air conditioner's operating conditions are within a preset normal range, the compressor frequency is controlled according to the preset phase current value's limiting current value and reducing current value to ensure the inverter air conditioner's heat exchange capacity. When the inverter air conditioner's operating conditions are not within the preset normal range, the preset phase current value's limiting current value and reducing current value are reduced in advance, and the compressor frequency is controlled according to the reduced phase current value's limiting current value and reducing current value. When the entire unit is in an abnormal situation, the compressor frequency control is intervened in advance, improving the reliability of the main board components of the inverter air conditioner.

[0225] According to an embodiment of the present invention, a storage medium corresponding to a control method for a variable frequency air conditioner is also provided. The storage medium includes a stored program, wherein the program controls the device where the storage medium is located to execute the control method for the variable frequency air conditioner described above when it is running.

[0226] 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.

[0227] By employing the technical solution of this invention, after the compressor of the inverter air conditioner starts, based on the length of the compressor's running time after startup, and considering the operating mode of the inverter air conditioner, the compressor's phase current value, the compressor frequency, the outdoor ambient temperature, the outdoor heat exchanger tube temperature, and the indoor heat exchanger tube temperature, the compressor frequency is controlled according to preset frequency-limiting current values ​​and frequency-reducing current values ​​when the inverter air conditioner's operating conditions are within a preset normal range, thus ensuring the heat exchange capacity of the inverter air conditioner. When the inverter air conditioner's operating conditions are not within a preset normal range, the preset frequency-limiting current values ​​and frequency-reducing current values ​​are reduced in advance, and the compressor frequency is controlled according to the reduced frequency-limiting current values ​​and frequency-reducing current values. By setting different frequency reduction protection limits for phase current values ​​based on the maximum frequency requirements under different modes and operating conditions, as well as the temperature rise of components under ambient temperature conditions, the reliability of the main board components of the inverter air conditioner can be improved, and the low-temperature heating capacity and high-temperature cooling capacity of the inverter air conditioner can also be improved.

[0228] 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.

[0229] 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 for a variable frequency air conditioner, characterized in that, include: After the compressor of the variable frequency air conditioner starts, the running time of the compressor after starting is timed to obtain the first cumulative running time of the compressor; The current operating mode of the inverter air conditioner is determined; and in the current operating mode of the inverter air conditioner, the upper limit frequency control parameter of the compressor of the inverter air conditioner is determined and denoted as the upper limit frequency control parameter of the compressor in the current operating mode; the current operating mode of the inverter air conditioner is either heating mode or cooling mode. The phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger tube temperature of the inverter air conditioner are obtained. When the first cumulative running time of the compressor is greater than or equal to the first preset running time, based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger tube temperature of the inverter air conditioner, the first preset control logic or the second preset control logic of the frequency reduction protection mode of the compressor phase current value is executed to realize the frequency reduction protection of the compressor phase current value. The first preset control logic is to reduce the preset phase current value and frequency reduction current value in advance when the operation of the inverter air conditioner is not in the preset normal condition, and control the compressor frequency according to the reduced phase current value and frequency reduction current value; the second preset control logic is to control the compressor frequency according to the preset phase current value and frequency reduction current value when the operation of the inverter air conditioner is in the preset normal condition. If the first cumulative running time of the compressor is less than the first preset running time, based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, the second preset control logic of the frequency reduction protection mode of the compressor phase current value is executed to realize the frequency reduction protection of the compressor phase current value.

2. The control method for a variable frequency air conditioner according to claim 1, characterized in that, Based on the compressor's upper limit frequency control parameters under the current operating mode, and combined with the compressor's phase current value, compressor frequency, outdoor ambient temperature of the inverter air conditioner, and outdoor heat exchanger pipe temperature of the inverter air conditioner, the first preset control logic or the second preset control logic of the compressor's phase current value frequency reduction protection mode is executed to achieve frequency reduction protection of the compressor's phase current value, including: Within a continuously set time period, determine the rate of change of the outdoor heat exchanger tube temperature of the inverter air conditioner; and determine whether the rate of change of the outdoor heat exchanger tube temperature of the inverter air conditioner is greater than or equal to the set tube temperature change rate. If it is determined that the rate of change of the outdoor heat exchanger pipe temperature of the variable frequency air conditioner is greater than or equal to the set pipe temperature change rate, then based on the upper limit frequency control parameter of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the variable frequency air conditioner, the first preset control logic of the frequency reduction protection mode of the compressor phase current value is executed to realize the frequency reduction protection of the compressor phase current value. If it is determined that the rate of change of the outdoor heat exchanger pipe temperature of the inverter air conditioner is less than the set pipe temperature change rate, then based on the upper limit frequency control parameter of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, the second preset control logic of the frequency reduction protection mode of the compressor phase current value is executed to realize the frequency reduction protection of the compressor phase current value.

3. The control method for a variable frequency air conditioner according to claim 2, characterized in that, The upper limit frequency control parameters of the compressor in the current operating mode include: the frequency limiting current value of the compressor in the current operating mode, the frequency reduction current value of the compressor in the current operating mode, the first frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, the second frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, and the upper limit frequency of the compressor in the current operating mode. Based on the compressor's upper frequency control parameters under the current operating mode, and combined with the compressor's phase current value, compressor frequency, and outdoor ambient temperature of the inverter air conditioner, the first preset control logic for the compressor's phase current value frequency reduction protection mode is executed to achieve frequency reduction protection for the compressor's phase current value, including: The frequency limiting current value of the compressor in the current operating mode is reduced by a set current value, and the frequency reduction current value of the compressor in the current operating mode is reduced by a set current value. Determine whether the phase current value of the compressor is greater than or equal to the difference between the first frequency limiting current value and the set current value; If it is determined that the phase current value of the compressor is greater than or equal to the difference between the first frequency limiting current value and the set current value, then the frequency of the compressor is reduced until the phase current value of the compressor is reduced to the point where the frequency reduction protection mode of the compressor phase current value is exited; at the same time, the upper limit frequency of the compressor in the current operating mode is reduced by the set frequency value to correct the upper limit frequency of the compressor. If it is determined that the phase current value of the compressor is less than the difference between the first frequency limiting current value and the set current value, then: If the phase current value of the compressor is greater than or equal to the difference between the second frequency limiting current value and the set current value, then the frequency of the compressor is kept at the current frequency and the frequency of the compressor is not allowed to increase. If the phase current value of the compressor is less than the difference between the second frequency limiting current value and the set current value, then the frequency of the compressor is set to the preset target frequency, and the frequency of the compressor is allowed to increase.

4. The control method for a variable frequency air conditioner according to claim 3, characterized in that, Based on the compressor's upper limit frequency control parameters under the current operating mode, combined with the compressor's phase current value, compressor frequency, and outdoor ambient temperature of the inverter air conditioner, the first preset control logic for the compressor's phase current value frequency reduction protection mode is executed to achieve frequency reduction protection for the compressor's phase current value, and further includes: After reducing the upper limit frequency of the compressor in the current operating mode by a set frequency value, the operating time of the compressor is re-timed to obtain the second cumulative operating time of the compressor; and within the second cumulative operating time of the compressor, the rate of change of the outdoor ambient temperature of the air conditioner is determined. Determine whether the second cumulative running time of the compressor is greater than or equal to the second preset running time, or whether the rate of change of the outdoor ambient temperature of the air conditioner is greater than or equal to the set temperature change rate; If so, exit the frequency reduction protection mode of the compressor's phase current value and stop correcting the upper limit frequency of the compressor in the current operating mode; Otherwise, return to the previous state and re-execute the first or second preset control logic of the compressor phase current value frequency reduction protection mode based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger tube temperature of the inverter air conditioner, so as to realize the frequency reduction protection of the compressor phase current value.

5. The control method for a variable frequency air conditioner according to any one of claims 1 to 4, characterized in that, The upper limit frequency control parameters of the compressor in the current operating mode include: the frequency limiting current value of the compressor in the current operating mode, the frequency reduction current value of the compressor in the current operating mode, the first frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, the second frequency limiting current value corresponding to the outdoor ambient temperature of the inverter air conditioner in the current operating mode, and the upper limit frequency of the compressor in the current operating mode. Based on the compressor's upper frequency control parameters under the current operating mode, and combined with the compressor's phase current value, compressor frequency, and outdoor ambient temperature of the inverter air conditioner, the second preset control logic for the compressor's phase current value frequency reduction protection mode is executed to achieve frequency reduction protection for the compressor's phase current value, including: Determine whether the phase current value of the compressor is greater than or equal to the first frequency limiting current value; If it is determined that the phase current value of the compressor is greater than or equal to the first frequency limiting current value, the frequency of the compressor is reduced until the phase current value of the compressor is reduced to the point where the frequency reduction protection mode of the phase current value of the compressor is exited; at the same time, the upper limit frequency of the compressor in the current operating mode is reduced by a set frequency value to correct the upper limit frequency of the compressor. If it is determined that the phase current value of the compressor is less than the first frequency limiting current value, then: If the phase current value of the compressor is greater than or equal to the second frequency limiting current value, then the frequency of the compressor shall be maintained at the current frequency and the frequency of the compressor shall not be allowed to increase. If the phase current value of the compressor is less than the second frequency limiting current value, then the frequency of the compressor is set to the preset target frequency, and the frequency of the compressor is allowed to increase.

6. The control method for a variable frequency air conditioner according to claim 5, characterized in that, Based on the compressor's upper limit frequency control parameters under the current operating mode, and combined with the compressor's phase current value, compressor frequency, and outdoor ambient temperature of the inverter air conditioner, the second preset control logic for the compressor's phase current value frequency reduction protection mode is executed to achieve frequency reduction protection for the compressor's phase current value. This also includes: After reducing the upper limit frequency of the compressor in the current operating mode by a set frequency value, the operating time of the compressor is re-timed to obtain the second cumulative operating time of the compressor; and within the second cumulative operating time of the compressor, the rate of change of the outdoor ambient temperature of the air conditioner is determined. Determine whether the second cumulative running time of the compressor is greater than or equal to the second preset running time, or whether the rate of change of the outdoor ambient temperature of the air conditioner is greater than or equal to the set temperature change rate; If so, exit the frequency reduction protection mode of the compressor's phase current value and stop correcting the upper limit frequency of the compressor in the current operating mode; Otherwise, return to the previous state and re-execute the second preset control logic of the compressor phase current value frequency reduction protection mode based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, so as to realize the frequency reduction protection of the compressor phase current value.

7. A control device for a variable frequency air conditioner, characterized in that, include: The control unit is configured to time the running time of the compressor after it starts, and obtain the first cumulative running time of the compressor. The control unit is further configured to determine the current operating mode of the inverter air conditioner; and in the current operating mode of the inverter air conditioner, determine the upper limit frequency control parameter of the compressor of the inverter air conditioner, denoted as the upper limit frequency control parameter of the compressor in the current operating mode; the current operating mode of the inverter air conditioner is either heating mode or cooling mode. The acquisition unit is configured to acquire the phase current value of the compressor, acquire the frequency of the compressor, acquire the outdoor ambient temperature of the inverter air conditioner, and acquire the outdoor heat exchanger tube temperature of the inverter air conditioner. The control unit is further configured to, when the first cumulative running time of the compressor is greater than or equal to the first preset running time, based on the upper limit frequency control parameters of the compressor in the current operating mode, and in combination with the phase current value of the compressor, the frequency of the compressor, the outdoor ambient temperature of the inverter air conditioner, and the outdoor heat exchanger tube temperature of the inverter air conditioner, execute the first preset control logic or the second preset control logic of the frequency reduction protection mode of the compressor's phase current value, so as to realize the frequency reduction protection of the compressor's phase current value. The first preset control logic is to reduce the preset phase current value and frequency reduction current value in advance when the operation of the inverter air conditioner is not in the preset normal condition, and control the compressor frequency according to the reduced phase current value and frequency reduction current value; the second preset control logic is to control the compressor frequency according to the preset phase current value and frequency reduction current value when the operation of the inverter air conditioner is in the preset normal condition. The control unit is further configured to, when the first cumulative running time of the compressor is less than the first preset running time, execute a second preset control logic for a frequency reduction protection mode of the compressor's phase current value based on the upper limit frequency control parameters of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, so as to realize frequency reduction protection of the compressor's phase current value.

8. The control device for a variable frequency air conditioner according to claim 7, characterized in that, The control unit, based on the compressor's upper limit frequency control parameters under the current operating mode, and in conjunction with the compressor's phase current value, compressor frequency, outdoor ambient temperature of the inverter air conditioner, and outdoor heat exchanger pipe temperature of the inverter air conditioner, executes a first preset control logic or a second preset control logic for the compressor's phase current value frequency reduction protection mode to achieve frequency reduction protection for the compressor's phase current value, including: Within a continuously set time period, determine the rate of change of the outdoor heat exchanger tube temperature of the inverter air conditioner; and determine whether the rate of change of the outdoor heat exchanger tube temperature of the inverter air conditioner is greater than or equal to the set tube temperature change rate. If it is determined that the rate of change of the outdoor heat exchanger pipe temperature of the variable frequency air conditioner is greater than or equal to the set pipe temperature change rate, then based on the upper limit frequency control parameter of the compressor under the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the variable frequency air conditioner, the first preset control logic of the frequency reduction protection mode of the compressor phase current value is executed to realize the frequency reduction protection of the compressor phase current value. If it is determined that the rate of change of the outdoor heat exchanger pipe temperature of the inverter air conditioner is less than the set pipe temperature change rate, then based on the upper limit frequency control parameter of the compressor in the current operating mode, combined with the phase current value of the compressor, the frequency of the compressor, and the outdoor ambient temperature of the inverter air conditioner, the second preset control logic of the frequency reduction protection mode of the compressor phase current value is executed to realize the frequency reduction protection of the compressor phase current value.

9. A variable frequency air conditioner, characterized in that, include: The control device for a variable frequency air conditioner as described in any one of claims 7 to 8.

10. A storage medium, characterized in that, The storage medium includes a stored program, wherein, when the program is executed, the device containing the storage medium is controlled to perform the control method of the variable frequency air conditioner as described in any one of claims 1 to 6.

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