Control method and control device of air conditioner compressor and air conditioner

Abstract

This invention discloses a control method, control device, and air conditioner compressor. The control method includes: acquiring the current three-phase current and current bus voltage of the compressor; acquiring a current adjustment bus voltage command based on the current three-phase current; acquiring a current feedback modulation rate based on the current bus voltage; determining the current feedback modulation rate deviation to be 0 when the current feedback modulation rate is greater than the modulation rate setting and the current adjustment bus voltage command is less than the maximum limit value of the voltage command; otherwise, determining the current feedback modulation rate deviation to be the difference between the modulation rate setting and the current feedback modulation rate; determining a current field weakening control current based on the current feedback modulation rate deviation; performing field weakening control based on the current field weakening control current; and performing power factor correction control based on the current adjustment bus voltage command. Using this invention, the performance of the compressor in different control processes can be improved.

Description

Technical Field

[0001] This invention belongs to the field of compressor control technology, specifically, it relates to a control method, control device and air conditioner compressor. Background Technology

[0002] The compressor control of a variable frequency air conditioner typically includes power factor correction control and field weakening control. Power factor correction control adjusts and matches the input and output power of the air conditioning control system to achieve the optimal power factor, thereby improving system energy efficiency, reducing energy consumption, and enhancing system reliability and stability. Field weakening control reduces the compressor's main magnetic flux, enabling it to operate at higher speeds while maintaining a certain output power. Field weakening control is usually achieved by adjusting the stator current, particularly by increasing the demagnetizing current component of the stator's d-axis to maintain voltage balance during high-speed operation.

[0003] In related technologies, power factor correction typically employs a constant bus command voltage as the target value for power factor correction control. While using a constant bus command voltage is simple, it can easily lead to high energy consumption and low efficiency, especially under light loads and load variations. This can prevent the system from operating at its optimal state, resulting in unnecessary energy loss and decreased system efficiency.

[0004] Therefore, how to reduce compressor energy consumption and improve compressor efficiency while ensuring the stability of the compressor system under weak magnetic control, and how to optimize the performance of the compressor in different control processes, are technical problems that need to be solved. Summary of the Invention

[0005] One of the objectives of this invention is to provide a control method and control device for an air conditioner compressor, thereby improving the performance of the compressor in different control processes.

[0006] To achieve the above-mentioned objectives, the improved air conditioner compressor control method of the present invention is implemented using the following technical solution:

[0007] A method for controlling an air conditioner compressor, comprising:

[0008] When the compressor is in field weakening control mode, the current three-phase current and the current bus voltage of the compressor are obtained.

[0009] The current d-axis voltage and current q-axis voltage are obtained based on the current three-phase current; the current d-axis voltage and current q-axis voltage are processed to obtain a processed voltage signal; the processed voltage signal is multiplied by the reciprocal of the adjustment coefficient, and the product is determined as the current adjustment bus voltage command;

[0010] The current feedback modulation rate is obtained based on the current bus voltage.

[0011] When the current feedback modulation rate is greater than the modulation rate setting and the current adjustment bus voltage command is less than the maximum voltage command limit, the current feedback modulation rate deviation is determined to be 0, the current field weakening control current is determined according to the current feedback modulation rate deviation, field weakening control is performed according to the current field weakening control current, and power factor correction control is performed according to the current adjustment bus voltage command.

[0012] When the current feedback modulation rate is not greater than the modulation rate setting or the current adjustment bus voltage command is greater than or equal to the maximum limit value of the voltage command, the current feedback modulation rate deviation is determined to be the difference between the modulation rate setting and the current feedback modulation rate. The current field weakening control current is determined based on the current feedback modulation rate deviation. Field weakening control is performed based on the current field weakening control current. Power factor correction control is performed based on the current adjustment bus voltage command.

[0013] In some embodiments of this application, the adjustment coefficient is determined using the following process:

[0014] Obtain the harmonic components of the current phase current of the compressor, and obtain the current fundamental component and the current nth harmonic component based on the harmonic components of the current phase current; n is the harmonic number and is a natural number greater than 1.

[0015] Calculate the sum of multiple specified harmonic components in the current nth harmonic component, and use it as the current harmonic component sum;

[0016] Compare the current harmonic component with the current fundamental component;

[0017] If the ratio of the sum of the current harmonic components to the current fundamental component is less than a set ratio, the adjustment coefficient is taken as a reference value; the set ratio is a positive number less than 1.

[0018] If the ratio of the current harmonic component to the current fundamental component is greater than or equal to the set ratio, the adjustment coefficient is taken as a correction value; the correction value is determined according to the reference value, and the correction value is less than the reference value.

[0019] In some embodiments of this application, the sum of multiple specified harmonic components in the current nth harmonic component is calculated as the current harmonic component sum, specifically including:

[0020] Arrange the current nth harmonic components in ascending order of harmonic order;

[0021] Take the specified number of odd-order harmonic components that are ranked first as the specified harmonic components, calculate the sum of all the specified harmonic components, and take it as the sum of the current harmonic components.

[0022] In some embodiments of this application, the current d-axis voltage and the current q-axis voltage are processed to obtain a processed voltage signal, specifically including:

[0023] Calculate the square root of the sum of the square of the current d-axis voltage and the square of the current q-axis voltage, and determine the result as the processed voltage signal.

[0024] In some embodiments of this application, the current d-axis voltage and the current q-axis voltage are processed to obtain a processed voltage signal, specifically including:

[0025] Calculate the square root of the sum of the square of the current d-axis voltage and the square of the current q-axis voltage, and determine the result as the initial voltage signal;

[0026] The initial voltage signal is processed to obtain the processed voltage signal.

[0027] In some embodiments of this application, the initial voltage signal is processed to obtain the processed voltage signal, specifically including:

[0028] Acquire multiple initial voltage signals within the currently set time period;

[0029] The average value of the multiple initial voltage signals within the current set time period is determined as the processed voltage signal;

[0030] Alternatively, the maximum value among the multiple initial voltage signals within the currently set time period can be determined as the processed voltage signal;

[0031] Alternatively, the larger of the average value of the multiple initial voltage signals within the current set time period and the average value of the multiple initial voltage signals within the previous set time period can be determined as the processed voltage signal.

[0032] Alternatively, the larger of the maximum value among the multiple initial voltage signals within the current set time period and the maximum value among the multiple initial voltage signals within the previous set time period can be determined as the processed voltage signal.

[0033] In some embodiments of this application, the initial voltage signal is processed to obtain the processed voltage signal, specifically including:

[0034] Acquire multiple initial voltage signals within the current electrical cycle; the electrical cycle is the period during which the compressor's stator current changes from 0° to 360°.

[0035] The average value of the multiple initial voltage signals within the current electrical cycle is determined as the processed voltage signal;

[0036] Alternatively, the maximum value among the multiple initial voltage signals within the current electrical cycle can be determined as the processed voltage signal;

[0037] Alternatively, the larger of the average value of the multiple initial voltage signals in the current electrical cycle and the average value of the multiple initial voltage signals in the previous electrical cycle can be determined as the processed voltage signal.

[0038] Alternatively, the larger of the maximum value among the multiple initial voltage signals in the current electrical cycle and the maximum value among the multiple initial voltage signals in the previous electrical cycle can be determined as the processed voltage signal.

[0039] In some embodiments of this application, the initial voltage signal is processed to obtain the processed voltage signal, specifically including:

[0040] Acquire multiple initial voltage signals within the current mechanical cycle; the mechanical cycle is the cycle in which the compressor rotor rotates from 0° to 360°.

[0041] The average value of the multiple initial voltage signals within the current mechanical cycle is determined as the processed voltage signal;

[0042] Alternatively, the maximum value among the multiple initial voltage signals within the current mechanical cycle can be determined as the processed voltage signal;

[0043] Alternatively, the larger of the average value of the multiple initial voltage signals in the current mechanical cycle and the average value of the multiple initial voltage signals in the previous mechanical cycle can be determined as the processed voltage signal.

[0044] Alternatively, the larger of the maximum value among the multiple initial voltage signals in the current mechanical cycle and the maximum value among the multiple initial voltage signals in the previous mechanical cycle can be determined as the processed voltage signal.

[0045] To achieve the aforementioned objectives, the air conditioner compressor control device provided by this invention employs the following technical solution:

[0046] A control device for an air conditioner compressor, comprising:

[0047] The three-phase current acquisition unit is used to acquire the current three-phase current of the compressor;

[0048] Bus voltage acquisition unit, used to acquire the current bus voltage of the compressor;

[0049] The bus voltage adjustment command acquisition unit is used to acquire the current d-axis voltage and the current q-axis voltage based on the current three-phase current, process the current d-axis voltage and the current q-axis voltage to obtain the processed voltage signal, and multiply the processed voltage signal by the reciprocal of the adjustment coefficient, and the product is determined as the current bus voltage adjustment command.

[0050] A feedback modulation rate acquisition unit is used to acquire the current feedback modulation rate based on the current bus voltage.

[0051] The control unit is configured to, when the compressor is in a field-weakening control mode, determine that the current feedback modulation rate deviation is 0 when the conditions are met that the current feedback modulation rate is greater than the modulation rate setting and the current adjustment bus voltage command is less than the maximum limit of the voltage command; determine the current field-weakening control current based on the current feedback modulation rate deviation; perform field-weakening control based on the current field-weakening control current; and perform power factor correction control based on the current adjustment bus voltage command. Furthermore, when the conditions are met that the current feedback modulation rate is not greater than the modulation rate setting or the current adjustment bus voltage command is greater than or equal to the maximum limit of the voltage command, determine that the current feedback modulation rate deviation is the difference between the modulation rate setting and the current feedback modulation rate; determine the current field-weakening control current based on the current feedback modulation rate deviation; perform field-weakening control based on the current field-weakening control current; and perform power factor correction control based on the current adjustment bus voltage command. The present invention also provides an air conditioner including a compressor, the air conditioner further including the above-described air conditioner compressor control device.

[0052] Compared with the prior art, the advantages and positive effects of the present invention are:

[0053] The air conditioner compressor control method and control device provided by this invention, in the field weakening control mode, the actual bus voltage command is not a fixed value, but is adjusted in real time according to the changes in compressor load. Power factor correction control is performed based on the adjusted bus voltage command, enabling the system bus voltage to dynamically adjust with load changes. This achieves a higher power factor while reducing system power loss, and allows the compressor system to quickly reach and maintain a stable operating state, improving the compressor system's efficiency. Simultaneously, the feedback modulation rate used to determine the field weakening control current is adjusted according to the magnitude of the bus voltage command and the magnitude of the feedback modulation rate. Deviations are handled such that when the bus voltage command is less than the maximum limit, the power factor correction control still has a margin for boost control. If the feedback modulation rate is greater than the set modulation rate, the feedback modulation rate deviation is forcibly set to 0 to reduce the field weakening control current or mitigate its fluctuations. This achieves the goal of reducing or mitigating bus voltage fluctuations in field weakening control. Thus, while fully utilizing the boost capability of power factor correction control to increase the bus voltage, it avoids large bus voltage fluctuations that could lead to runaway power factor correction control and compressor control, or even compressor shutdown, thereby improving the stability of the field weakening control mode. Therefore, by using this invention to control the compressor, while reducing compressor energy consumption and improving compressor efficiency, the stability of the compressor system during field weakening control is ensured, optimizing compressor performance in different control processes.

[0054] Other features and advantages of the present invention will become clearer after reading the detailed embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0056] Figure 1 A flowchart of the first embodiment of the air conditioner compressor control method provided by the present invention;

[0057] Figure 2 A flowchart of the second embodiment of the air conditioner compressor control method provided by the present invention;

[0058] Figure 3 A structural block diagram of an embodiment of the control device for an air conditioner compressor provided by the present invention;

[0059] Figure 4 The voltage waveform and feedback modulation rate deviation waveform are shown in one embodiment. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0061] It should be noted that the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they can be implemented by those skilled in the art. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0062] Figure 1 The diagram shown is a flowchart of the first embodiment of the air conditioner compressor control method provided by the present invention.

[0063] like Figure 1 As shown, this embodiment employs the following process to perform compressor control.

[0064] S11: When the compressor is in the field weakening control mode, obtain the current three-phase current and the current bus voltage of the compressor.

[0065] Determining whether the compressor is in a weak magnetic control mode can be achieved using existing related technologies, and this embodiment does not limit the specific determination method.

[0066] In some embodiments, the compressor speed can be used as the basis for judgment. If the compressor speed is greater than the base speed, it is determined that the compressor is in the weak magnetic control mode.

[0067] The current three-phase current of the compressor refers to the three-phase current of the compressor obtained by real-time sampling according to a set sampling frequency. The method for obtaining the three-phase current adopts existing technology, and this embodiment does not limit the acquisition method.

[0068] The current bus voltage of the compressor refers to the compressor bus voltage acquired in real time according to a set sampling frequency. The method for acquiring the bus voltage adopts existing technology, and this embodiment does not limit the acquisition method.

[0069] S12: Determine the current bus voltage adjustment command based on the current three-phase current; obtain the current feedback modulation rate based on the current bus voltage.

[0070] The process of determining the current bus voltage adjustment command based on the current three-phase current includes:

[0071] The current d-axis voltage and current q-axis voltage are obtained based on the current three-phase current. This process is implemented using existing technology, and this embodiment is not limited thereto. In some embodiments, the current three-phase current is first transformed using a conversion unit via a Clarke transformation to obtain the compressor current I in the α-axis direction of the two-phase stationary coordinate system.α and the current I in the β-axis direction β Then, combining the estimated compressor rotor angle, the current I in the α-axis direction is controlled by the conversion unit. α and the current I in the β-axis direction β Perform a Park transformation to obtain the current actual d-axis current I in a two-phase rotating coordinate system. d and the current q-axis actual current I q Then, combined with the given d-axis current I... d * q-axis given current I q * For the current actual d-axis current I d Current q-axis actual current I q The current d-axis voltage V is obtained by processing with a current regulator. d and the current q-axis voltage V q The method for obtaining the compressor rotor angle estimate can be achieved using existing technology. The d-axis given current I... d * and q-axis given current I q * The value is known.

[0072] The current d-axis voltage and the current q-axis voltage are processed to obtain the processed voltage signal.

[0073] The processed voltage signal is multiplied by the reciprocal of the adjustment coefficient, and the product is used to determine the current bus voltage adjustment command. The adjustment coefficient can be a set value or an obtainable value; this embodiment does not limit the method of determining its value.

[0074] The specific method for determining the current feedback modulation rate based on the current bus voltage is implemented using existing technology, and this embodiment does not limit or further elaborate on this.

[0075] S13: Determine whether the current feedback modulation rate is greater than the modulation rate setting. If yes, proceed to step S14; otherwise, proceed to step S15.

[0076] The modulation rate is set to a known value, and the specific value can be selected according to the system structure and actual needs.

[0077] S14: Determine whether the current bus voltage adjustment command is less than the maximum voltage command limit. If yes, proceed to step S16; otherwise, proceed to step S15.

[0078] The maximum voltage command limit is a known value, and the specific value can be selected according to the system structure and actual needs.

[0079] S15: If the conditions of step S13 (determining that the current feedback modulation rate is not greater than the modulation rate setting) or step S14 (determining that the current adjustment bus voltage command is greater than or equal to the maximum limit value of the voltage command) are met, the current feedback modulation rate deviation is determined to be the difference between the modulation rate setting and the current feedback modulation rate. Then, step S17 is executed.

[0080] When the current feedback modulation rate is not greater than the modulation rate setting, the field weakening control depth is shallow, the system operates relatively smoothly, and the bus voltage fluctuation is small. When the current adjustment bus voltage command is greater than or equal to the maximum voltage command limit, it indicates that the boost capability of the power factor correction control has reached its maximum. In both cases, conventional field weakening control is executed, and the difference between the modulation rate setting and the current feedback modulation rate is determined as the current feedback modulation rate deviation.

[0081] S16: When the conditions are met in step S13 (determining that the current feedback modulation rate is greater than the modulation rate setting) and step S14 (determining that the current adjustment bus voltage command is less than the maximum voltage command limit), the current feedback modulation rate deviation is set to 0. Then, step S17 is executed.

[0082] The current feedback modulation rate is greater than the set modulation rate, indicating a deep field weakening control that is prone to bus voltage fluctuations. However, the current bus voltage adjustment command is less than the maximum voltage command limit, indicating that the power factor correction control also has boost capability. When both conditions are met, the current feedback modulation rate deviation is forcibly set to 0, reducing the depth of field weakening control and mitigating its impact on bus voltage fluctuations. Simultaneously, the boost capability of the power factor correction control is fully utilized to increase the bus voltage.

[0083] S17: Determine the current field weakening control current based on the current feedback modulation rate deviation.

[0084] The process is implemented using existing technology, and this embodiment does not limit or further elaborate on it.

[0085] S18: Perform power factor correction control based on the current bus voltage adjustment command; perform field weakening control based on the current field weakening control current.

[0086] In this embodiment, under the field weakening control mode, the d-axis and q-axis voltages are obtained based on the compressor's three-phase current. A processed voltage signal is then obtained from these voltages. Finally, the current adjustment bus voltage command is determined based on the processed voltage signal and the adjustment coefficient. Therefore, the actual bus voltage command is not a fixed value but adjusts in real time according to changes in the compressor load. Power factor correction control based on the adjusted bus voltage command enables the system bus voltage to dynamically adjust with load changes, achieving a higher power factor while reducing system power loss. This also allows the compressor system to quickly reach and maintain a stable operating state, improving the compressor system's efficiency.

[0087] Meanwhile, in the field weakening control mode, the feedback modulation rate deviation used to determine the field weakening control current is processed according to the magnitude of the bus voltage command and the magnitude of the feedback modulation rate. When the bus voltage command is less than the maximum limit of the voltage command, it indicates that the power factor correction control still has a margin for boost control. If the feedback modulation rate is greater than the modulation rate setting at this time, the feedback modulation rate deviation is forcibly assigned to 0, reducing the field weakening control current or slowing down the fluctuation of the field weakening control current. This achieves the purpose of reducing or slowing down the bus voltage fluctuation in field weakening control, making full use of the boost capability of the power factor correction control to increase the bus voltage. While increasing the bus voltage, it avoids the problem of large bus voltage fluctuations causing the power factor correction control and compressor control to run out of control or even cause the compressor to stop, thus improving the stability of the field weakening control mode.

[0088] Therefore, by using the above method to control the compressor, the energy consumption of the compressor is reduced and the working efficiency of the compressor is improved, while ensuring the stability of the compressor system under weak magnetic control, and optimizing the performance of the compressor in different control processes.

[0089] In some other embodiments, the adjustment factor used to determine the current bus voltage adjustment command is a dynamically variable value, and the value of the adjustment factor is determined using the following process:

[0090] First, the harmonic components of the current phase current of the compressor are obtained. Based on the harmonic components of the current phase current, the current fundamental component and the current nth harmonic component are obtained. Here, n is the harmonic order, and n is a natural number greater than 1. The current of any phase of the compressor can be selected as the current phase current. The method of performing harmonic analysis on the current to obtain the harmonic components, and then obtaining the fundamental component and the nth harmonic component (higher harmonic components) from the harmonic components, can be implemented using existing technologies, and this embodiment does not limit this approach.

[0091] Then, the sum of multiple specified harmonic components in the current nth harmonic component is calculated as the current harmonic component sum.

[0092] The specified subharmonic components can be selected according to the actual situation.

[0093] In some embodiments, taking advantage of the characteristic that harmonic components gradually decrease with increasing harmonic order, to improve processing speed, the current nth harmonic components are arranged in ascending order of harmonic order, and a specified number of the top-ranked harmonic components are selected as the specified harmonic components. The specified number can be selected according to the actual situation. For example, in some embodiments, the specified number is 5. Then, after arranging the current nth harmonic components in ascending order of harmonic order, the top 5 harmonic components, that is, the 2nd, 3rd, 4th, 5th, and 6th harmonic components, are selected as the specified harmonic components.

[0094] In other embodiments, the specified harmonic components are determined by the following process: The current n-th harmonic components are arranged in ascending order of harmonic order, and a specified number of odd-order harmonic components at the top of the order are selected as the specified harmonic components. Odd-order harmonics have a greater impact on compressors and air conditioning systems, potentially causing additional losses, vibrations, and noise. Since the number of harmonic components gradually decreases with increasing order, selecting the top-order odd-order harmonic components for summation calculations balances processing speed and accuracy. The specified number can be selected based on actual conditions. For example, in some embodiments, the specified number is 5. Then, after arranging the current n-th harmonic components in ascending order of harmonic order, the top 5 odd-order harmonic components—that is, the 3rd, 5th, 7th, 9th, and 11th harmonic components—are selected as the specified harmonic components.

[0095] After obtaining the sum of the current harmonic components, the sum of the current harmonic components is compared with the already obtained current fundamental component, and the value of the adjustment coefficient is determined based on the comparison result.

[0096] Specifically, if the ratio of the sum of the current harmonic components to the current fundamental component is less than a set ratio, the adjustment coefficient is set to a reference value. The reference value is a known value, and its specific value can be set according to actual needs. Under this value, using the bus voltage command determined by the reference value for compressor control can improve power utilization and the compressor's high-speed operation capability. The set ratio is a positive number less than 1, and its value is known and can be specifically selected according to actual needs; this embodiment does not limit the specific value. In some embodiments, the set ratio ranges from [0.10, 0.25]. When the ratio of the sum of the current harmonic components to the current fundamental component is less than the set ratio, that is, when the sum of the current harmonic components is less than the product of the current fundamental component and the set ratio, it indicates that the harmonic components are within an acceptable range. The adjustment coefficient is set to a known reference value to obtain higher power utilization and the compressor's high-speed operation capability, thereby achieving the goal of reducing energy consumption and improving performance.

[0097] If the ratio of the sum of the current harmonic components to the current fundamental component is greater than or equal to a set ratio, the adjustment coefficient is set to a correction value. The correction value is determined based on a reference value and must be less than the reference value. If the ratio of the sum of the current harmonic components to the current fundamental component is not less than a set ratio (i.e., the sum of the current harmonic components is not less than the product of the current fundamental component and the set ratio), it indicates a large harmonic component and a high degree of phase current distortion. In this case, a smaller correction value is used to obtain a larger bus voltage command value. Compressor control is then performed based on this larger bus voltage command value to reduce the harmonic component of the compressor phase current and improve system stability.

[0098] In the above embodiments, the adjustment coefficient of the bus voltage command is adjusted in real time according to the harmonic components of the phase current fed back by the compressor. While ensuring that the compressor has the ability to operate at high speed and instantaneous overload capacity, the distortion of the compressor phase current is reduced, so as to achieve the purpose of taking into account the compressor performance, efficiency, service life and the stability of the air conditioning system in which the compressor is used.

[0099] Figure 2 The flowchart shown is a second embodiment of the control method for an air conditioner compressor provided by the present invention. Specifically, it is a flowchart of an embodiment for determining the current adjustment bus voltage command.

[0100] In this embodiment, the current bus voltage adjustment command is dynamically acquired based on the load size, and power factor correction is performed using this command. Specifically, this embodiment acquires the current bus voltage adjustment command using the following process.

[0101] S21: Get the current three-phase current of the compressor.

[0102] S22: Obtain the current d-axis voltage and the current q-axis voltage based on the current three-phase current.

[0103] For the specific implementation of steps S21 and S22 above, please refer to [link / reference]. Figure 1 The corresponding description of the embodiments.

[0104] S23: Calculate the square root of the sum of the square of the current d-axis voltage and the square of the current q-axis voltage, and determine the result as the initial voltage signal.

[0105] The initial voltage signal is denoted as V0, and the current d-axis voltage is V. d The current q-axis voltage is V. q Then we have:

[0106]

[0107] S24: Process the initial voltage signal to obtain the processed voltage signal.

[0108] S25: Multiply the processed voltage signal by the reciprocal of the adjustment coefficient, and the product is determined as the current bus voltage adjustment command.

[0109] In step S24 above, the initial voltage signal is processed to obtain the processed voltage signal, which can be achieved in various ways.

[0110] In some embodiments, the initial voltage signal is processed to obtain a processed voltage signal, specifically including:

[0111] Acquire multiple initial voltage signals within the currently set time period. The length of the set time period can be set according to actual needs.

[0112] Then, the average value of multiple initial voltage signals within the current set time period is determined as the processed voltage signal.

[0113] By using the average value of the initial voltage signal within a set time period as the processed voltage signal, the influence of all initial voltage signals can be taken into account, ensuring the accuracy of the determined bus voltage command as much as possible, thereby improving the accuracy of compressor control. Moreover, by acquiring a processed voltage signal only once every set time period and adjusting the bus voltage command once, the instability of system operation caused by frequent adjustments to the bus voltage command can be avoided.

[0114] In some other embodiments, the initial voltage signal is processed to obtain a processed voltage signal, specifically including:

[0115] Acquire multiple initial voltage signals within the currently set time period. The length of the set time period can be set according to actual needs.

[0116] The maximum value among multiple initial voltage signals within the currently set time period is determined as the processed voltage signal.

[0117] By using the maximum value of multiple initial voltage signals within a set time period as the processed voltage signal, the larger voltage signal has a greater impact on the result, which can ensure the accuracy of the determined bus voltage command as much as possible, thereby improving the accuracy of compressor control. Moreover, by acquiring a processed voltage signal only once every set time period and adjusting the bus voltage command once, the instability of system operation caused by frequent adjustments to the bus voltage command can be avoided.

[0118] In some other embodiments, the initial voltage signal is processed to obtain a processed voltage signal, specifically including:

[0119] Acquire multiple initial voltage signals within the currently set time period. The length of the set time period can be set according to actual needs.

[0120] The larger of the average value of multiple initial voltage signals within the current set time period and the average value of multiple initial voltage signals within the previous set time period is determined as the processed voltage signal; or, the larger of the maximum value among multiple initial voltage signals within the current set time period and the maximum value among multiple initial voltage signals within the previous set time period is determined as the processed voltage signal.

[0121] By selecting the maximum or average value of multiple initial voltage signals within two adjacent set time periods as the processed voltage signal, the number of bus voltage command adjustments is reduced, and the instability of system operation caused by frequent adjustments is avoided. At the same time, the accuracy of the processed voltage signal is improved as much as possible, thereby ensuring the accuracy of the determined bus voltage command and improving the accuracy of compressor control.

[0122] In other embodiments, the initial voltage signal is processed to obtain a processed voltage signal, specifically including:

[0123] Acquire multiple initial voltage signals within the current electrical cycle. The electrical cycle is the period during which the compressor's stator current changes from 0° to 360°, and it is also the time required for the compressor to output a complete electrical signal.

[0124] Then, the average value of multiple initial voltage signals within the current electrical cycle is determined as the processed voltage signal.

[0125] By using the average value of the initial voltage signal within one electrical cycle as the processed voltage signal, the influence of all initial voltage signals within a complete electrical signal cycle can be considered, ensuring the accuracy of the determined bus voltage command as much as possible, thereby improving the accuracy of compressor control. Moreover, by acquiring a processed voltage signal only once every electrical cycle and adjusting the bus voltage command once, the instability of system operation caused by frequent adjustments to the bus voltage command can be avoided.

[0126] In some other embodiments, the initial voltage signal is processed to obtain a processed voltage signal, specifically including:

[0127] Acquire multiple initial voltage signals within the current electrical cycle.

[0128] The maximum value among multiple initial voltage signals within the current electrical cycle is determined as the processed voltage signal.

[0129] By using the maximum value of multiple initial voltage signals within one electrical cycle as the processed voltage signal, the larger voltage signal has a greater impact on the result, which can ensure the accuracy of the determined bus voltage command as much as possible, thereby improving the accuracy of compressor control. Moreover, by acquiring a processed voltage signal only once every electrical cycle and adjusting the bus voltage command once, the instability of system operation caused by frequent adjustments to the bus voltage command can be avoided.

[0130] In some other embodiments, the initial voltage signal is processed to obtain a processed voltage signal, specifically including:

[0131] Acquire multiple initial voltage signals within the current electrical cycle.

[0132] The larger of the average value of multiple initial voltage signals in the current electrical cycle and the average value of multiple initial voltage signals in the previous electrical cycle is determined as the processed voltage signal; or, the larger of the maximum value among multiple initial voltage signals in the current electrical cycle and the maximum value among multiple initial voltage signals in the previous electrical cycle is determined as the processed voltage signal.

[0133] By selecting the maximum or average value of multiple initial voltage signals within two adjacent electrical cycles as the processed voltage signal, the number of bus voltage command adjustments is reduced, and the instability of system operation caused by frequent adjustments is avoided. At the same time, the accuracy of the processed voltage signal is improved as much as possible, thereby ensuring the accuracy of the determined bus voltage command and improving the accuracy of compressor control.

[0134] In other embodiments, the initial voltage signal is processed to obtain a processed voltage signal, specifically including:

[0135] Acquire multiple initial voltage signals within the current mechanical cycle. The mechanical cycle is the period during which the compressor rotor rotates from 0° to 360°. A mechanical cycle typically comprises multiple electrical cycles, and the mechanical cycle is the product of the number of pole pairs and the number of electrical cycles.

[0136] Then, the average value of multiple initial voltage signals within the current mechanical cycle is determined as the processed voltage signal.

[0137] By using the average value of the initial voltage signal within a mechanical cycle as the processed voltage signal, the influence of all initial voltage signals within a complete mechanical cycle can be considered, ensuring the accuracy of the determined bus voltage command as much as possible, thereby improving the accuracy of compressor control. Moreover, by acquiring a processed voltage signal only once every mechanical cycle and adjusting the bus voltage command once, the instability of system operation caused by frequent adjustments to the bus voltage command can be avoided.

[0138] In some other embodiments, the initial voltage signal is processed to obtain a processed voltage signal, specifically including:

[0139] Acquire multiple initial voltage signals within the current mechanical cycle.

[0140] The maximum value among multiple initial voltage signals within the current mechanical cycle is determined as the processed voltage signal.

[0141] By using the maximum value of multiple initial voltage signals within a mechanical cycle as the processed voltage signal, the larger voltage signal has a greater impact on the result, which can ensure the accuracy of the determined bus voltage command as much as possible, thereby improving the accuracy of compressor control. Moreover, by acquiring a processed voltage signal only once every mechanical cycle and adjusting the bus voltage command once, the instability of system operation caused by frequent adjustments to the bus voltage command can be avoided.

[0142] In some other embodiments, the initial voltage signal is processed to obtain a processed voltage signal, specifically including:

[0143] Acquire multiple initial voltage signals within the current mechanical cycle.

[0144] The larger of the average value of multiple initial voltage signals in the current mechanical cycle and the average value of multiple initial voltage signals in the previous mechanical cycle is determined as the processed voltage signal; or, the larger of the maximum value among multiple initial voltage signals in the current mechanical cycle and the maximum value among multiple initial voltage signals in the previous mechanical cycle is determined as the processed voltage signal.

[0145] By selecting the maximum or average value of multiple initial voltage signals within two adjacent mechanical cycles as the processed voltage signal, the number of bus voltage command adjustments is reduced, and the instability of system operation caused by frequent adjustments is avoided. At the same time, the accuracy of the processed voltage signal is improved as much as possible, thereby ensuring the accuracy of the determined bus voltage command and improving the accuracy of compressor control.

[0146] In some other embodiments, the initial voltage signal determined by the square root of the sum of the square of the current d-axis voltage and the square of the current q-axis voltage is directly used as the processed voltage signal to determine the bus voltage command.

[0147] Figure 3 A structural block diagram of an embodiment of the control device for an air conditioner compressor provided by the present invention is shown. The control device of this embodiment includes structural units, the relationships between structural units, and the function of each structural unit, which are described in detail below.

[0148] like Figure 3 As shown, the compressor control device includes:

[0149] The three-phase current acquisition unit 31 is used to acquire the current three-phase current of the compressor.

[0150] The bus voltage adjustment command acquisition unit 32 is used to acquire the current d-axis voltage and the current q-axis voltage based on the current three-phase current acquired by the three-phase current acquisition unit 31, process the current d-axis voltage and the current q-axis voltage to obtain the processed voltage signal, and multiply the processed voltage signal by the reciprocal of the adjustment coefficient, and the product is determined as the current bus voltage adjustment command.

[0151] The bus voltage acquisition unit 33 is used to acquire the current bus voltage of the compressor.

[0152] The feedback modulation rate acquisition unit 34 is used to acquire the current feedback modulation rate based on the current bus voltage acquired by the bus voltage acquisition unit 33.

[0153] The control unit 35 is configured to, when the compressor is in the field weakening control mode, determine the current feedback modulation rate deviation as 0 when the current feedback modulation rate obtained by the feedback modulation rate acquisition unit 34 is greater than the modulation rate setting and the current adjustment bus voltage command obtained by the adjustment bus voltage command acquisition unit 32 is less than the maximum limit value of the voltage command; determine the current field weakening control current based on the current feedback modulation rate deviation; perform field weakening control based on the current field weakening control current; and perform power factor correction control based on the current adjustment bus voltage command. Furthermore, when the current feedback modulation rate is not greater than the modulation rate setting or the current adjustment bus voltage command is greater than or equal to the maximum limit value of the voltage command, determine the current feedback modulation rate deviation as the difference between the modulation rate setting and the current feedback modulation rate; determine the current field weakening control current based on the current feedback modulation rate deviation; perform field weakening control based on the current field weakening control current; and perform power factor correction control based on the current adjustment bus voltage command.

[0154] The control device of the above structure runs the corresponding software program, performs the corresponding functions, and follows the instructions. Figure 1 The compressor control method embodiments and other embodiments perform compressor control to achieve the desired effect. Figure 1 The corresponding technical effects of the embodiments and other embodiments.

[0155] The compressor control device described in the above embodiment is applied to the control of the compressor in an air conditioner, which can improve the performance of the air conditioner in different control processes.

[0156] Figure 4 The diagram shown is a voltage waveform and a feedback modulation rate deviation waveform of one embodiment.

[0157] Figure 4 The curve shown in Figure (a) represents the compressor speed at 110 rpm. Figure 1 The waveform of the feedback modulation rate deviation determined by the method of the embodiment is shown. In the figure, the horizontal axis represents time in seconds; the vertical axis represents the magnitude of the feedback modulation rate deviation, which is a unitless numerical value.

[0158] Figure 4 Figure (b) shows two curves, L1 and L2. Curve L1 is a magnified view of the feedback modulation rate deviation within a specific time period (8.7-9 seconds) in Figure (a). The vertical axis corresponding to curve L1 is the right-hand vertical axis, with no unit value, representing the magnitude of the feedback modulation rate deviation. Curve L2 represents the deviation during the corresponding time period using... Figure 1 The waveform diagram formed by the difference between the adjustment bus voltage command and the maximum limit value of the voltage command determined by the method of the embodiment, with the vertical axis corresponding to curve L2 being the left vertical axis, and the unit being volts.

[0159] As can be seen from Figure (b), when the difference between the adjustment bus voltage command and the maximum limit of the voltage command is negative, that is, when the adjustment bus voltage command is less than the maximum limit of the voltage command, the feedback modulation rate deviation does not have a value less than 0.

[0160] Figure 4 Figure (c) shows the compressor speed at 110 rpm. Figure 1 The method of this embodiment yields a voltage waveform diagram generated by the adjustment bus voltage command. In the diagram, the horizontal axis represents time in seconds, and the vertical axis represents voltage in volts. As can be seen from diagram (c), although the bus voltage command exhibits some fluctuations, these fluctuations are relatively small. Through speed monitoring, the compressor is able to operate stably at approximately 110 rpm.

[0161] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions claimed by the present invention.

Claims

1. A control method for an air conditioner compressor, characterized in that, The control method includes: When the compressor is in field weakening control mode, the current three-phase current and the current bus voltage of the compressor are obtained. The current d-axis voltage and current q-axis voltage are obtained based on the current three-phase current; the current d-axis voltage and current q-axis voltage are processed to obtain a processed voltage signal; the processed voltage signal is multiplied by the reciprocal of the adjustment coefficient, and the product is determined as the current adjustment bus voltage command; The current feedback modulation rate is obtained based on the current bus voltage. When the current feedback modulation rate is greater than the modulation rate setting and the current adjustment bus voltage command is less than the maximum voltage command limit, the current feedback modulation rate deviation is determined to be 0, the current field weakening control current is determined according to the current feedback modulation rate deviation, field weakening control is performed according to the current field weakening control current, and power factor correction control is performed according to the current adjustment bus voltage command. When the current feedback modulation rate is not greater than the modulation rate setting or the current adjustment bus voltage command is greater than or equal to the maximum limit value of the voltage command, the current feedback modulation rate deviation is determined to be the difference between the modulation rate setting and the current feedback modulation rate. The current field weakening control current is determined based on the current feedback modulation rate deviation. Field weakening control is performed based on the current field weakening control current. Power factor correction control is performed based on the current adjustment bus voltage command.

2. The control method for an air conditioner compressor according to claim 1, characterized in that, The adjustment factor is determined using the following process: Obtain the harmonic components of the current phase current of the compressor, and obtain the current fundamental component and the current nth harmonic component based on the harmonic components of the current phase current; n is the harmonic number and is a natural number greater than 1. Calculate the sum of multiple specified harmonic components in the current nth harmonic component, and use it as the current harmonic component sum; Compare the current harmonic component with the current fundamental component; If the ratio of the sum of the current harmonic components to the current fundamental component is less than a set ratio, the adjustment coefficient is taken as a reference value; the set ratio is a positive number less than 1. If the ratio of the sum of the current harmonic components to the current fundamental component is greater than or equal to the set ratio, the adjustment coefficient is taken as a correction value; the correction value is determined according to the reference value, and the correction value is less than the reference value.

3. The control method for an air conditioner compressor according to claim 2, characterized in that, Calculating the sum of multiple specified harmonic components in the current nth harmonic component as the current harmonic component sum, specifically includes: Arrange the current nth harmonic components in ascending order of harmonic order; Take the specified number of odd-order harmonic components that are ranked first as the specified harmonic components, calculate the sum of all the specified harmonic components, and take it as the sum of the current harmonic components.

4. The control method for an air conditioner compressor according to any one of claims 1 to 3, characterized in that, The current d-axis voltage and the current q-axis voltage are processed to obtain a processed voltage signal, specifically including: Calculate the square root of the sum of the square of the current d-axis voltage and the square of the current q-axis voltage, and determine the result as the processed voltage signal.

5. The control method for an air conditioner compressor according to any one of claims 1 to 3, characterized in that, The current d-axis voltage and the current q-axis voltage are processed to obtain a processed voltage signal, specifically including: Calculate the square root of the sum of the square of the current d-axis voltage and the square of the current q-axis voltage, and determine the result as the initial voltage signal; The initial voltage signal is processed to obtain the processed voltage signal.

6. The control method for an air conditioner compressor according to claim 5, characterized in that, The initial voltage signal is processed to obtain the processed voltage signal, specifically including: Acquire multiple initial voltage signals within the currently set time period; The average value of the multiple initial voltage signals within the current set time period is determined as the processed voltage signal; Alternatively, the maximum value among the multiple initial voltage signals within the currently set time period can be determined as the processed voltage signal; Alternatively, the larger of the average value of the multiple initial voltage signals within the current set time period and the average value of the multiple initial voltage signals within the previous set time period can be determined as the processed voltage signal. Alternatively, the larger of the maximum value among the multiple initial voltage signals within the current set time period and the maximum value among the multiple initial voltage signals within the previous set time period can be determined as the processed voltage signal.

7. The control method for an air conditioner compressor according to claim 5, characterized in that, The initial voltage signal is processed to obtain the processed voltage signal, specifically including: Acquire multiple initial voltage signals within the current electrical cycle; the electrical cycle is the period during which the compressor's stator current changes from 0° to 360°. The average value of the multiple initial voltage signals within the current electrical cycle is determined as the processed voltage signal; Alternatively, the maximum value among the multiple initial voltage signals within the current electrical cycle can be determined as the processed voltage signal; Alternatively, the larger of the average value of the multiple initial voltage signals in the current electrical cycle and the average value of the multiple initial voltage signals in the previous electrical cycle can be determined as the processed voltage signal. Alternatively, the larger of the maximum value among the multiple initial voltage signals in the current electrical cycle and the maximum value among the multiple initial voltage signals in the previous electrical cycle can be determined as the processed voltage signal.

8. The control method for an air conditioner compressor according to claim 5, characterized in that, The initial voltage signal is processed to obtain the processed voltage signal, specifically including: Acquire multiple initial voltage signals within the current mechanical cycle; the mechanical cycle is the cycle in which the compressor rotor rotates from 0° to 360°. The average value of the multiple initial voltage signals within the current mechanical cycle is determined as the processed voltage signal; Alternatively, the maximum value among the multiple initial voltage signals within the current mechanical cycle can be determined as the processed voltage signal; Alternatively, the larger of the average value of the multiple initial voltage signals in the current mechanical cycle and the average value of the multiple initial voltage signals in the previous mechanical cycle can be determined as the processed voltage signal. Alternatively, the larger of the maximum value among the multiple initial voltage signals in the current mechanical cycle and the maximum value among the multiple initial voltage signals in the previous mechanical cycle can be determined as the processed voltage signal.

9. A control device for an air conditioner compressor, characterized in that, The control device includes: The three-phase current acquisition unit is used to acquire the current three-phase current of the compressor; Bus voltage acquisition unit, used to acquire the current bus voltage of the compressor; The bus voltage adjustment command acquisition unit is used to acquire the current d-axis voltage and the current q-axis voltage based on the current three-phase current, process the current d-axis voltage and the current q-axis voltage to obtain the processed voltage signal, and multiply the processed voltage signal by the reciprocal of the adjustment coefficient, and the product is determined as the current bus voltage adjustment command. A feedback modulation rate acquisition unit is used to acquire the current feedback modulation rate based on the current bus voltage. The control unit is configured to, when the compressor is in field weakening control mode, determine the current feedback modulation rate deviation as 0 when the conditions are met that the current feedback modulation rate is greater than the modulation rate setting and the current adjustment bus voltage command is less than the maximum voltage command limit, determine the current field weakening control current based on the current feedback modulation rate deviation, perform field weakening control based on the current field weakening control current, and perform power factor correction control based on the current adjustment bus voltage command; and when the conditions are met that the current feedback modulation rate is not greater than the modulation rate setting or the current adjustment bus voltage command is greater than or equal to the maximum voltage command limit, determine the current feedback modulation rate deviation as the difference between the modulation rate setting and the current feedback modulation rate, determine the current field weakening control current based on the current feedback modulation rate deviation, perform field weakening control based on the current field weakening control current, and perform power factor correction control based on the current adjustment bus voltage command.

10. An air conditioner, comprising a compressor, characterized in that, The air conditioner also includes the control device for the air conditioner compressor as described in claim 9.

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