A current harmonic suppression method and device for an electrolytic capacitor-free driving system

Abstract

This application provides a method and apparatus for suppressing current harmonics in an electrolytic capacitor-free drive system, relating to the field of permanent magnet synchronous motor drive control, and used to improve grid-side current quality. The method includes: acquiring a sawtooth wave of the same frequency, which is generated based on the LC resonant frequency; comparing the sawtooth wave with a given value to obtain a rectangular wave, and amplifying the rectangular wave to obtain a given damping pulse; shifting the phase of the given damping pulse according to the three-phase grid-side current to obtain an applied damping pulse; obtaining an α-axis voltage compensation component and a β-axis voltage compensation component based on the applied damping pulse; superimposing the α-axis voltage compensation component onto the α-axis voltage to obtain an α-axis voltage command; superimposing the β-axis voltage compensation component onto the β-axis voltage to obtain a β-axis voltage command; and applying the α-axis voltage command and the β-axis voltage command to a space vector pulse width modulation (SVPWM) inverter.

Description

Technical Field

[0001] This application relates to the field of permanent magnet synchronous motor drive control, and in particular to a method and apparatus for suppressing current harmonics in an electrolytic capacitor-free drive system. Background Technology

[0002] Permanent magnet synchronous motors, as electromechanical energy conversion devices, have been widely used in aerospace, industrial transmission, household appliances and other fields.

[0003] In permanent magnet synchronous motor drive systems, electrolytic capacitors or non-electrolytic capacitors are used. Permanent magnet synchronous motor drive systems using electrolytic capacitors are bulky, costly, and have a short lifespan. Therefore, nowadays permanent magnet synchronous motor drive systems use film capacitors or ceramic capacitors to replace traditional electrolytic capacitors. Film capacitors have the advantages of small size, low cost, and long lifespan.

[0004] However, compared to permanent magnet synchronous motor drive systems with electrolytic capacitors, electrolytic capacitor-free drive systems exhibit LC resonance, which leads to the generation of grid-side current harmonics and reduces the quality of the grid-side current. Summary of the Invention

[0005] This application provides a current harmonic suppression method and apparatus for an electrolytic capacitor-free drive system, which is used to improve the quality of grid-side current.

[0006] In a first aspect, this application provides a method for suppressing current harmonics in an electrolytic capacitor-free drive system, comprising:

[0007] Obtain a sawtooth wave of the same frequency, which is generated based on the LC resonant frequency;

[0008] The same frequency sawtooth wave and the given value of the sawtooth wave are compared to obtain a rectangular wave, and the rectangular wave is amplified to obtain a given damping pulse;

[0009] The applied damping pulse is obtained by phase shifting a given damping pulse based on the three-phase current on the grid side.

[0010] Based on the applied damping pulse, the α-axis voltage compensation component and the β-axis voltage compensation component are obtained;

[0011] The α-axis voltage compensation component is superimposed on the α-axis voltage to obtain the α-axis voltage command;

[0012] The β-axis voltage compensation component is superimposed on the β-axis voltage to obtain the β-axis voltage command;

[0013] Apply α-axis voltage commands and β-axis voltage commands to the space vector pulse width modulation (SVPWM) inverter.

[0014] The technical solution provided in this application provides at least the following beneficial effects: A sawtooth wave with the same frequency as the LC resonant frequency is generated. The sawtooth wave with the same frequency is compared with a given value to obtain a rectangular wave with the same frequency as the LC resonant frequency. Amplifying the rectangular wave yields a given damping pulse with the same frequency as the LC resonant frequency. Then, the phase of the given damping pulse is shifted according to the three-phase current on the grid side, so that the high-level moment of the given damping pulse coincides with the time when the three-phase current on the grid side is at its trough, thus obtaining the applied damping pulse. It should be understood that shifting the phase of the given damping pulse does not change its frequency, so the applied damping pulse is also with the same frequency as the LC resonant frequency. Based on the applied damping pulse with the same frequency as the LC resonant frequency, α-axis voltage compensation components and β-axis voltage compensation components are obtained. Because the voltage compensation components are obtained from the applied damping pulse with the same frequency as the LC resonant frequency, the voltage compensation components can more effectively suppress harmonics generated by the LC resonant frequency. The α-axis voltage compensation component is superimposed on the α-axis voltage to obtain the α-axis voltage command; the β-axis voltage compensation component is superimposed on the β-axis voltage to obtain the β-axis voltage command. Both the α-axis and β-axis voltage commands are then applied to the SVPWM inverter.

[0015] Thus, a sawtooth wave with the same frequency as the LC resonant frequency is generated, which in turn yields a rectangular wave with the same frequency as the LC resonant frequency and a given damping pulse, ensuring that the given damping pulse is synchronized with the LC resonant frequency. The phase of the given damping pulse is then shifted based on the three-phase grid current to obtain the applied damping pulse, which in turn yields a voltage compensation component. This voltage compensation component is superimposed on the voltage to obtain a voltage command, which is then applied to the SVPWM inverter. By suppressing harmonics in the voltage generated by LC resonance through the voltage compensation component, the resonance phenomenon is suppressed, thereby improving the grid-side current quality.

[0016] In one possible implementation, the applied damping pulse is obtained by phase shifting a given damping pulse based on the grid-side three-phase current, including: time detection of the grid-side three-phase current to obtain the time when the grid-side three-phase current is at a trough; and phase shifting the given damping pulse based on the time when the grid-side three-phase current is at a trough to obtain the applied damping pulse.

[0017] In another possible implementation, the α-axis voltage compensation component and the β-axis voltage compensation component are obtained based on the applied damping pulse, including: obtaining the α-axis voltage compensation component based on the applied damping pulse and the α-axis voltage; and obtaining the β-axis voltage compensation component based on the applied damping pulse and the β-axis voltage.

[0018] In another possible implementation, the α-axis voltage compensation component is obtained based on the applied damping pulse and the α-axis voltage, including: if the α-axis voltage is above a preset voltage, determining that the α-axis voltage compensation component is the negative of the applied damping pulse; if the α-axis voltage is below the preset voltage, determining that the α-axis voltage compensation component is the applied damping pulse.

[0019] In another possible implementation, the β-axis voltage compensation component is obtained based on the applied damping pulse and the β-axis voltage: if the β-axis voltage is above a preset voltage, the β-axis voltage compensation component is determined to be the negative of the applied damping pulse; if the β-axis voltage is below the preset voltage, the β-axis voltage compensation component is determined to be the applied damping pulse.

[0020] Secondly, this application provides a current harmonic suppression device, the device comprising:

[0021] The acquisition unit is used to acquire the same frequency sawtooth wave, which is generated based on the LC resonant frequency.

[0022] The comparator unit is used to compare a sawtooth wave of the same frequency with a given value of a sawtooth wave to obtain a rectangular wave;

[0023] The amplification unit is used to amplify the rectangular wave to obtain a given damped pulse;

[0024] The phase calculation unit is used to shift the phase of a given damping pulse based on the three-phase current on the grid side to obtain the applied damping pulse;

[0025] The damping voltage generation unit is used to obtain the α-axis voltage compensation component and the β-axis voltage compensation component based on the applied damping pulse.

[0026] The first addition unit is used to superimpose the α-axis voltage compensation component onto the α-axis voltage to obtain the α-axis voltage command, and output the α-axis voltage command to the SVPWM inverter.

[0027] The second addition unit is used to superimpose the β-axis voltage compensation component onto the β-axis voltage to obtain the β-axis voltage command, and output the β-axis voltage command to the SVPWM inverter.

[0028] In one possible implementation, the phase operation unit is specifically used to: perform time detection on the grid-side three-phase current to obtain the time when the grid-side three-phase current is at the trough; and, based on the time when the grid-side three-phase current is at the trough, perform phase shift on a given damping pulse to obtain the applied damping pulse.

[0029] In another possible implementation, the damping voltage generation unit is specifically used to: obtain the α-axis voltage compensation component based on the applied damping pulse and the α-axis voltage; and obtain the β-axis voltage compensation component based on the applied damping pulse and the β-axis voltage.

[0030] In another possible implementation, the damping voltage generation unit is specifically used to: if the α-axis voltage is above a preset voltage, determine that the α-axis voltage compensation component is the negative number of the applied damping pulse;

[0031] If the α-axis voltage is below the preset voltage, the α-axis voltage compensation component is determined to be the applied damping pulse;

[0032] If the β-axis voltage is above the preset voltage, the β-axis voltage compensation component is determined to be the negative of the applied damping pulse;

[0033] If the β-axis voltage is below the preset voltage, the β-axis voltage compensation component is determined to be the applied damping pulse.

[0034] Thirdly, this application provides a computer-readable storage medium comprising: computer software instructions; when the computer software instructions are executed in an electronic device, they cause the electronic device to implement the method described in the first aspect.

[0035] Fourthly, this application provides a computer program product that, when run on a computer, causes the computer to perform the steps of the relevant method described in the first aspect above, so as to implement the method of the first aspect above. Attached Figure Description

[0036] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of the present invention and do not constitute a limitation on the technical solutions of the present invention.

[0037] Figure 1 A block diagram of a capacitorless motor drive system provided in this application embodiment;

[0038] Figure 2 A schematic diagram of a damping voltage generation unit provided in an embodiment of this application;

[0039] Figure 3 A schematic flowchart illustrating a current harmonic suppression method for an electrolytic capacitor-free drive system provided in this application embodiment;

[0040] Figure 4 A schematic diagram of a sawtooth wave waveform with the same frequency provided in an embodiment of this application;

[0041] Figure 5 A schematic diagram of a given value waveform for a sawtooth wave of the same frequency provided in an embodiment of this application;

[0042] Figure 6 A schematic diagram of a rectangular wave waveform provided in an embodiment of this application;

[0043] Figure 7A schematic flowchart illustrating another current harmonic suppression method for an electrolytic capacitor-free drive system provided in this application embodiment;

[0044] Figure 8 A schematic flowchart illustrating another current harmonic suppression method for an electrolytic capacitor-free drive system provided in this application embodiment;

[0045] Figure 9 This is a schematic diagram of the overall process of a current harmonic suppression method for an electrolytic capacitor-free drive system provided in an embodiment of this application;

[0046] Figure 10 This is a schematic diagram of the composition of a current harmonic suppression device provided in an embodiment of this application;

[0047] Figure 11 This is a schematic diagram of the hardware structure of a current harmonic suppression device provided in an embodiment of this application. Detailed Implementation

[0048] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0049] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0050] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0051] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Furthermore, when describing pipelines, the terms "connected" and "linked" as used in this application have the meaning of establishing electrical connection. The specific meaning needs to be understood in conjunction with the context.

[0052] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0053] Permanent magnet synchronous motors, as electromechanical energy conversion devices, have been widely used in aerospace, industrial transmission, household appliances and other fields.

[0054] In permanent magnet synchronous motor drive systems, electrolytic capacitors or non-electrolytic capacitors are used. Permanent magnet synchronous motor drive systems using electrolytic capacitors are bulky, costly, and have a short lifespan. Therefore, nowadays permanent magnet synchronous motor drive systems use film capacitors or ceramic capacitors to replace traditional electrolytic capacitors. Film capacitors have the advantages of small size, low cost, and long lifespan.

[0055] However, compared to permanent magnet synchronous motor drive systems with electrolytic capacitors, permanent magnet synchronous motor drive systems without electrolytic capacitors experience periodic fluctuations in bus voltage due to the lack of electrolytic capacitors for energy storage and smoothing. Furthermore, the input line resistance is very small, resulting in weak system damping capability and a high likelihood of LC resonance between the inductor and capacitor. This leads to LC oscillation components in both the input current and bus voltage, increasing harmonics in the grid-side input current and decreasing the power factor. This severely impacts the grid-side input quality and pollutes the grid-side current.

[0056] Based on this, this application provides a current harmonic suppression method for an electrolytic capacitor-free drive system. A sawtooth wave with the same frequency as the LC resonant frequency is generated. The sawtooth wave with the same frequency is compared with a given value to obtain a rectangular wave with the same frequency as the LC resonant frequency. Amplifying the rectangular wave yields a given damping pulse with the same frequency as the LC resonant frequency. Then, the phase of the given damping pulse is shifted according to the three-phase current on the grid side, so that the high-level moment of the given damping pulse coincides with the time when the three-phase current on the grid side is at its trough, thus obtaining the applied damping pulse. It should be understood that shifting the phase of the given damping pulse does not change its frequency, so the applied damping pulse is also with the same frequency as the LC resonant frequency. Based on the applied damping pulse with the same frequency as the LC resonant frequency, α-axis voltage compensation components and β-axis voltage compensation components are obtained. Because the voltage compensation components are obtained from the applied damping pulse with the same frequency as the LC resonant frequency, the voltage compensation components can more effectively suppress harmonics generated by the LC resonant frequency. The α-axis voltage compensation component is superimposed on the α-axis voltage to obtain the α-axis voltage command; the β-axis voltage compensation component is superimposed on the β-axis voltage to obtain the β-axis voltage command. Both the α-axis and β-axis voltage commands are then applied to the SVPWM inverter.

[0057] Thus, a sawtooth wave with the same frequency as the LC resonant frequency is generated, which in turn yields a rectangular wave with the same frequency as the LC resonant frequency and a given damping pulse, ensuring that the given damping pulse is synchronized with the LC resonant frequency. The phase of the given damping pulse is then shifted based on the three-phase grid current to obtain the applied damping pulse, which in turn yields a voltage compensation component. This voltage compensation component is superimposed on the voltage to obtain a voltage command, which is then applied to the SVPWM inverter. The voltage compensation component suppresses harmonics in the voltage, thereby improving the grid-side current quality.

[0058] Figure 1 The diagram shown is a block diagram of a capacitor-free motor drive system provided in this application according to an exemplary embodiment. Figure 1 As shown, the electrolytic capacitor-free motor drive system includes a first subtraction unit 101, a speed regulator 102, a second subtraction unit 103, a third subtraction unit 104, a current regulator 105, an inverse Park conversion unit 106, a first addition unit 107, a second addition unit 108, an SVPWM unit 109, a three-phase electrolytic capacitor-free driver 110, a permanent magnet synchronous motor (PMSM) 111, an encoder 112, a Clarke conversion unit 113, a Park conversion unit 114, a speed and position calculation unit 115, a comparator unit 201, a proportional amplification unit 202, a time detection unit 203, a phase calculation unit 204, a damping voltage generation unit 205, and a controller. Figure 1 (Not shown in the image).

[0059] In some embodiments, the above-described electrolytic capacitor-free motor drive system can be applied to various control systems, such as air conditioning systems. The air conditioning system includes multi-split air conditioning systems.

[0060] In some embodiments, the first subtraction unit 101 is used to calculate the motor speed ω obtained by the speed-position calculation unit 115. e Motor speed command Subtracting the values ​​yields the speed difference Δω. e and the speed difference Δω e Output to speed regulator 102.

[0061] In some embodiments, the speed regulator 102 is a specialized design of this regulating plate, which includes self-adjusting and leveling components, and is mainly used to automatically adjust the controlled parameters of the system composed of parameters such as pressure, tension, speed, and temperature.

[0062] In some embodiments, the second subtraction unit 103 is used to transform the two-phase rotating current I obtained by the Park transformation unit 114. d Current command of the motor d-axis Subtracting them yields the current difference ΔI along the d-axis. d and the current difference ΔI along the d-axis d Input to current regulator 105.

[0063] In some embodiments, the third subtraction unit 104 is used to transform the two-phase rotating current I obtained by the Park transformation unit 114. q Current command for the motor's q-axis Subtracting them gives the current difference ΔI along the q-axis. q and the current difference ΔI along the q-axis q Input to current regulator 105.

[0064] In some embodiments, the current regulator 105 is an electronic device for regulating circuit current. The name of the current regulator is different; the former is called a current regulator to increase reactance.

[0065] In some embodiments, the inverse Park conversion unit 106 is used to convert two-phase rotating voltage commands and Transformed to two-phase static voltage U α and U β .

[0066] In some embodiments, the first addition unit 107 is used to add the voltage compensation component ΔU of the α-axis of the motor. α The voltage U superimposed on the α axis of the motor α Above, generate voltage commands for the α-axis.

[0067] In some embodiments, the second addition unit 108 is used to process the voltage compensation component ΔU of the β-axis of the motor. β The voltage U superimposed on the β axis of the motor β Generate voltage commands for the β-axis.

[0068] In some embodiments, the main idea of ​​SVPWM is to use the ideal flux linkage circle of the stator of a three-phase symmetrical motor under three-phase symmetrical sinusoidal voltage supply as a reference standard, and to appropriately switch different switching modes of the three-phase inverter to form a PWM wave, using the resulting actual flux linkage vector to track its accurate flux linkage circle. Traditional SPWM methods focus on the power supply to generate an adjustable frequency and voltage sinusoidal power supply, while SVPWM methods consider the inverter system and asynchronous motor as a whole, resulting in a simpler model and facilitating real-time control by a microprocessor.

[0069] A typical three-phase full-bridge circuit consists of three half-bridges composed of six switching devices. These six switching devices, combined (with opposite signals for the upper and lower half-bridges of the same bridge arm), provide eight safe switching states. Among these, the 000 and 111 states (representing the switching states of the three upper bridge arms) do not generate effective current in motor drives; therefore, they are called zero vectors. The other six switching states are six effective vectors. They divide the 360-degree voltage space into six 60-degree sectors. Using these six basic effective vectors and two zero vectors, any vector within 360 degrees can be synthesized. When synthesizing a specific vector, it is first decomposed into its two nearest basic vectors, and then represented by these two basic vectors. The magnitude of each basic vector is represented by its duration. The voltage vectors are synthesized using different time ratios, thus ensuring that the generated voltage waveform approximates a sine wave.

[0070] When driving a variable frequency motor, the vector direction changes continuously, so the vector action time needs to be calculated constantly. For ease of computer processing, a timer is typically used for calculation during synthesis (e.g., every 0.1ms). This way, only the action time of the two basic vectors within 0.1ms needs to be calculated. Since the sum of the two calculated times may be less than 0.1ms, the remaining time is used to insert an appropriate zero vector as needed. Because the synthesized drive waveform is very similar to PWM in this process, it can be called PWM. Furthermore, since this PWM is synthesized based on voltage space vectors, it is called SVPWM.

[0071] In some embodiments, the three-phase capacitorless driver 110 is used to implement frequency conversion drive.

[0072] In some embodiments, PMSM111 refers to a motor defined based on its back electromotive force: a permanent magnet synchronous motor with sinusoidal back electromotive force.

[0073] In some embodiments, the motor includes a direct axis (d-axis) and a quadrature axis (q-axis). The d-axis and q-axis are a coordinate system established on the motor rotor. This coordinate system rotates synchronously with the rotor. The direction of the rotor magnetic field is taken as the d-axis, and the direction perpendicular to the rotor magnetic field is taken as the q-axis.

[0074] In some embodiments, the motor further includes an α-axis and a β-axis, which are two-phase stationary rectangular coordinate systems established by the motor and are stationary.

[0075] In some embodiments, the encoder 112 is used to detect the operating position of the motor rotor.

[0076] In some embodiments, the conversion of sine current in a three-phase stationary 120-degree coordinate system (abc) into sine current in a two-phase stationary rectangular coordinate system (α-β) is called the Clark transformation.

[0077] In some embodiments, the Clark converter 113 is used to convert the three-phase static current I of the motor into a single current. a I b and I c Transformed to two-phase quiescent current I a and I β From the perspective of the stator, I a and I β These are mutually orthogonal time-generated current values.

[0078] In some embodiments, the conversion of a sine current in a two-phase stationary rectangular coordinate system (α-β) into a constant current in a two-phase rotating rectangular coordinate system (dq) is called the Park transformation.

[0079] In some embodiments, the Park conversion unit 114 is used to convert the two-phase quiescent current I a and I β Transformed into two-phase rotating current I d and I q I d and I q Let I be the orthogonal current in the rotating coordinate system. Under steady-state conditions, I... d and I q It is a constant. Through a proportional-integral (PI) controller, the output U is... d and U q This refers to the voltage vector applied to the motor. Further, the new switching angle is estimated through position estimation. Further, this is achieved by using the new angle θ. e The U output of the PI controller can be used to... d and U q After Park inverse transform, the orthogonal voltage value U in stationary coordinates is obtained. a and U β The new PWM duty cycle value is calculated using the SVPWM unit to generate the desired voltage vector.

[0080] In some embodiments, the rotational speed and position calculation unit 115 is used to deduce the rotational angle θ of the motor. e and motor speed ω e .

[0081] In some embodiments, comparator unit 201 is used to analyze the sawtooth wave U generated according to the LC resonant frequency. sawtooth and sawtooth wave given value U constantBy comparison, the rectangular wave U is obtained. rectangular .

[0082] In some embodiments, the same frequency sawtooth wave U sawtooth The amplitude is set to 1, and the sawtooth wave setpoint U constant Set to 0.8. In the same frequency sawtooth wave U... sawtooth The amplitude of the sawtooth wave is given by U. constant When the above condition is met, the comparator unit outputs 1; in the same frequency sawtooth wave U... sawtooth The amplitude of the sawtooth wave is given by U. constant When the comparator unit outputs 0, it generates a rectangular wave U with a 20% duty cycle, which is the same frequency as the LC resonant frequency. rectangular .

[0083] In some embodiments, the scaling amplification unit 202 is used to amplify the rectangular wave U rectangular Scaled up proportionally to generate a given damped pulse with the same frequency as the LC resonant frequency.

[0084] In some embodiments, the magnification factor of the scaling unit 202 is set to 60.

[0085] In some embodiments, the time detection unit 203 is used to perform time detection on the grid-side three-phase current to obtain the time when the grid-side three-phase current is at a trough.

[0086] In some embodiments, the phase calculation unit 204 is used to adjust the damping pulse according to the grid-side three-phase current. A phase shift is performed to obtain the applied damping pulse U. pulse .

[0087] In some embodiments, the phase operation unit 204 performs a phase operation on the damping pulse. Perform a phase shift to make the damping pulse The high-level voltage level exists at the same time as the three-phase current on the grid side is at its trough.

[0088] In some embodiments, the damping voltage generation unit 205 is configured to generate a damping voltage based on the applied damping pulse U. pulse The voltage compensation component ΔU of the motor's α-axis is obtained. α The voltage compensation component ΔU of the motor's β-axis β .

[0089] In some embodiments, such as Figure 2 As shown, if the voltage U on the α axis of the motor α If it is above 0, then the voltage compensation component ΔU on the α axis α For the applied damping pulse U pulse The negative number; if the voltage U of the motor's α axis αBelow 0, the voltage compensation component ΔU on the α axis α For the applied damping pulse U pulse .

[0090] Similarly, if the voltage U on the β axis of the motor β If it is above 0, then the voltage compensation component ΔU of the motor's β-axis β For the applied damping pulse U pulse The negative number; if the voltage U of the motor's β axis β Below 0, the voltage compensation component ΔU of the motor's β-axis β For the applied damping pulse U pulse .

[0091] In the embodiments shown in this application, a controller refers to a device that can generate operation control signals based on instruction opcodes and timing signals, instructing the electrolytic capacitor-free motor drive system to execute control commands. Exemplarily, the controller can be a central processing unit (CPU), a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. The controller can also be other devices with processing functions, such as circuits, devices, or software modules; this application does not impose any limitations on this.

[0092] In addition, the controller can be used to control the operation of various components in the electrolytic capacitor-free motor drive system, so that the electrolytic capacitor-free motor drive system can perform its predetermined functions.

[0093] Those skilled in the art will understand that Figure 1 The structure shown does not constitute a limitation on the electrolytic capacitor-free motor drive system. The electrolytic capacitor-free motor drive system may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0094] like Figure 3As shown, this application provides a method for suppressing current harmonics in a capacitor-free drive system. The execution subject of this method is a current harmonic suppression device or an air conditioner that can be used to execute the aforementioned method. The current harmonic suppression device can be the main control board or a part of the main control board in the air conditioner, or a combination of hardware such as a central processing unit (CPU), CPU, and memory, which is additionally installed in the air conditioner. The capacitor-free drive system current harmonic suppression method provided in this application includes the following steps:

[0095] S101, Obtain the same frequency sawtooth wave.

[0096] Among them, the sawtooth wave U of the same frequency sawtooth It is generated based on the LC resonant frequency, so the sawtooth wave U at the same frequency sawtooth The frequency is the same as the LC resonant frequency.

[0097] Figure 4 This is a schematic diagram of a sawtooth wave waveform with the same frequency, such as... Figure 4 As shown, the sawtooth wave U of the same frequency sawtooth The waveform periodically rises and falls in a straight line, and is a non-sinusoidal wave, that is, a waveform with a repeating structure of a straight diagonal line and a straight line perpendicular to the horizontal axis.

[0098] S102. Compare the sawtooth wave of the same frequency with the given value of the sawtooth wave to obtain a rectangular wave, and amplify the rectangular wave to obtain a given damping pulse.

[0099] The sawtooth wave setpoint can be preset at the factory for the electrolytic capacitor-free drive system, such as... Figure 5 The image shown is a schematic diagram of a sawtooth wave given value waveform provided in an embodiment of this application.

[0100] In some embodiments, in the same frequency sawtooth wave U sawtooth The amplitude of the sawtooth wave is given by U. constant When the above is true, the output is high; in the same frequency sawtooth wave U sawtooth The amplitude of the sawtooth wave is given by U. constant The output is low at the following time. Thus, by comparing the same-frequency sawtooth wave with the given value of the sawtooth wave, it is possible to obtain a sawtooth wave U with the same frequency. sawtooth Square waves U with the same frequency rectangular .

[0101] For example, by comparing a sawtooth wave of the same frequency with a given value of a sawtooth wave, the resulting rectangular wave can be as follows: Figure 6 As shown. By Figure 6 The content shown indicates that the rectangular wave Urectangular The waveform has periodic sharp rises and falls, and the waveform is rectangular, which is a non-sine wave.

[0102] In some embodiments, after obtaining the rectangular wave, the rectangular wave U can be... rectangular The input is fed into the proportional amplification unit, which then processes the rectangular wave U. rectangular The given damping pulse is obtained by proportionally amplifying it.

[0103] It should be understood that the rectangular wave U rectangular The purpose of scaling up is to provide a sufficiently damped pulse.

[0104] For example, the same frequency sawtooth wave U sawtooth The amplitude is set to 1, and the sawtooth wave setpoint U constant If set to 0.8, then when the sawtooth wave U of the same frequency... sawtooth When the amplitude is above 0.8, the output is high; in the same frequency sawtooth wave U sawtooth When the amplitude is below 0.8, the output is low. By comparing the sawtooth wave of the same frequency with the given value of the sawtooth wave, a rectangular wave U with a duty cycle of 20% can be obtained. rectangular Then the rectangular wave U rectangular Amplified 60 times proportionally, the given damping pulse is obtained.

[0105] In some embodiments, the scaling operation unit operates on a rectangular wave U rectangular The given damping pulse is obtained by proportionally amplifying it. Then, the given damping pulse The pulse is transmitted to the phase calculation unit. Correspondingly, the phase calculation unit receives the constant-damping pulse.

[0106] S103. The phase of the given damping pulse is shifted according to the three-phase current on the grid side to obtain the applied damping pulse.

[0107] In some embodiments, such as Figure 7 As shown, step S103 can be specifically implemented as S1031 and S1032.

[0108] S1031. Time detection is performed on the three-phase current on the grid side to obtain the time when the three-phase current on the grid side is at the trough.

[0109] Among them, the three-phase currents on the grid side are all sinusoidal alternating currents. Sinusoidal alternating current is a current that changes with time according to a sinusoidal function, and sinusoidal alternating current has peaks and troughs.

[0110] In some embodiments, the time detection unit acquires the grid-side three-phase current I. u Iv and I w The three-phase current on the grid side is time-detected to obtain the time when the three-phase current on the grid side is at its trough, which is used to determine the duration of a given damping pulse. Adjustments will be made.

[0111] In some embodiments, after the time detection unit obtains the time when the grid-side three-phase current is at a trough, it transmits the time when the grid-side three-phase current is at a trough to the phase calculation unit. Correspondingly, the phase calculation unit receives the time when the grid-side three-phase current is at a trough.

[0112] S1032. Based on the time when the three-phase current on the grid side is at its trough, the phase of the given damping pulse is shifted to obtain the applied damping pulse.

[0113] In some embodiments, the phase shifting of a given damping pulse based on the time when the grid-side three-phase current is at its trough, to obtain the applied damping pulse, can be specifically implemented as follows: the phase calculation unit shifts the phase of the given damping pulse based on the time when the grid-side three-phase current is at its trough. Perform phase shifting to give a given damped pulse The applied damping pulse U is obtained by shifting the time when the high level is at the same time as the time when the three-phase current on the grid side is at its trough. pulse .

[0114] S104. Based on the applied damping pulse, obtain the α-axis voltage compensation component and the β-axis voltage compensation component.

[0115] Optional, such as Figure 8 As shown, step S104 can be specifically implemented as follows:

[0116] S1041. Based on the applied damping pulse and α-axis voltage, obtain the α-axis voltage compensation component.

[0117] In some embodiments, the α-axis voltage compensation component is obtained based on the applied damping pulse and the α-axis voltage. Specifically, this can be achieved by having a damping voltage generation unit acquire the applied damping pulse, the α-axis voltage, and a preset voltage, and then obtain the α-axis voltage compensation component based on these parameters. The preset voltage is a value pre-set at the factory for the electrolytic capacitor-free drive system; for example, the preset voltage is 0.

[0118] Optionally, the damped voltage generation unit obtains the α-axis voltage U. α Compared with the preset voltage, the α-axis voltage U α Compared with the preset voltage, if the α-axis voltage U α Determine the α-axis voltage compensation component ΔU above the preset voltage. α For the applied damping pulse U pulse The negative number; if the α-axis voltage Uα Below the preset voltage, determine the α-axis voltage compensation component ΔU. α For the applied damping pulse U pulse And the α-axis voltage compensation component ΔU α Apply to the first addition unit.

[0119] S1042. Based on the applied damping pulse and β-axis voltage, obtain the β-axis voltage compensation component.

[0120] Similarly, the β-axis voltage compensation component can be obtained based on the applied damping pulse and β-axis voltage as follows: the damping voltage generation unit acquires the applied damping pulse, β-axis voltage and preset voltage, and obtains the β-axis voltage compensation component based on the applied damping pulse, β-axis voltage and preset voltage.

[0121] Optionally, the damped voltage generation unit obtains the β-axis voltage U. β Compared with the preset voltage, the β-axis voltage U β Compare the preset voltages; if the β-axis voltage U... β Determine the β-axis voltage compensation component ΔU above the preset voltage. β For the applied damping pulse U pulse The negative number; if the β-axis voltage U β Determine the β-axis voltage compensation component ΔU below the preset voltage. β For the applied damping pulse U pulse And the β-axis voltage compensation component ΔU β Apply to the second addition unit.

[0122] It should be noted that the execution order of steps S1041 and S1042 is not limited in the embodiments of this application. For example, step S1041 can be executed first, followed by step S1042; or step S1042 can be executed first, followed by step S1041; or steps S1041 and S1042 can be executed simultaneously.

[0123] S105. Superimpose the α-axis voltage compensation component onto the α-axis voltage to obtain the α-axis voltage command; superimpose the β-axis voltage compensation component onto the β-axis voltage to obtain the β-axis voltage command.

[0124] Understandable, α-axis voltage command It is the α-axis voltage U α After compensation component ΔU α The α-axis voltage command obtained after superposition Compared to U α It is less affected by harmonics and has higher voltage quality.

[0125] Similarly, β-axis voltage command Compared to Uβ It is less affected by harmonics and has higher voltage quality.

[0126] S106. Apply the α-axis voltage command and β-axis voltage command to the space vector pulse width modulation (SVPWM) inverter.

[0127] In some embodiments, the α-axis voltage command and β-axis voltage are input to the SVPWM inverter as parameters of the electrolytic capacitor-free drive system.

[0128] In summary, the current harmonic suppression method for an electrolytic capacitor-free drive system provided in this application generates a sawtooth wave of the same frequency as the LC resonant frequency. The sawtooth wave is compared with a given value to obtain a rectangular wave of the same frequency as the LC resonant frequency. Amplifying the rectangular wave yields a given damping pulse with the same LC resonant frequency. Then, the phase of the given damping pulse is shifted according to the three-phase current on the grid side, so that the high-level moment of the given damping pulse coincides with the time when the three-phase current on the grid side is at its trough, thus obtaining the applied damping pulse. It should be understood that shifting the phase of the given damping pulse does not change its frequency; therefore, the applied damping pulse is also of the same frequency as the LC resonant frequency. Based on the applied damping pulse of the same frequency as the LC resonant frequency, α-axis voltage compensation components and β-axis voltage compensation components are obtained. Because the voltage compensation components are obtained from the applied damping pulse of the same frequency as the LC resonant frequency, they can more effectively suppress harmonics generated by the LC resonant frequency. The α-axis voltage compensation component is superimposed on the α-axis voltage to obtain the α-axis voltage command; the β-axis voltage compensation component is superimposed on the β-axis voltage to obtain the β-axis voltage command. Both the α-axis and β-axis voltage commands are then applied to the SVPWM inverter.

[0129] The following example illustrates a current harmonic suppression method for an electrolytic capacitor-free drive system provided in this application. Figure 9 This is a schematic diagram of the overall process for a current harmonic suppression method for an electrolytic capacitor-free drive system provided in this application.

[0130] like Figure 9As shown, after the electrolytic capacitor-free drive system starts operating, the comparator unit acquires a sawtooth wave of the same frequency and a sawtooth wave setpoint. The sawtooth wave is generated based on the LC resonant frequency, and its frequency is the same as the LC resonant frequency. The comparator unit compares the sawtooth wave with the setpoint. If the amplitude of the sawtooth wave is above the setpoint, it outputs a high level; if the amplitude is below the setpoint, it outputs a low level. This comparison yields a rectangular wave with the same frequency as the LC resonant frequency, which is then output to the proportional amplifier unit. The proportional amplifier unit amplifies the rectangular wave to obtain a given damped pulse and outputs it to the phase operation unit.

[0131] The time detection unit detects the time of the three-phase current on the grid side, which are all sinusoidal alternating currents. A sinusoidal alternating current is a current that changes according to a sinusoidal function over time, exhibiting peaks and troughs. The unit obtains the time when the three-phase current on the grid side is at a trough and outputs this time to the phase calculation unit. After obtaining the time when the three-phase current on the grid side is at a trough and a given damping pulse, the phase calculation unit shifts the phase of the given damping pulse based on the time when the three-phase current on the grid side is at a trough, making the high-level time in the given damping pulse the same as the time when the three-phase current on the grid side is at a trough, thus obtaining the applied damping pulse, which is output to the damping voltage generation unit.

[0132] The damping voltage generation unit acquires the α-axis voltage, β-axis voltage, and applied damping pulse. Based on the applied damping pulse and α-axis voltage, it obtains the α-axis voltage compensation component. When the α-axis voltage is above a preset voltage, the α-axis voltage compensation component is the negative of the applied damping pulse; when the α-axis voltage is below the preset voltage, the α-axis voltage compensation component is the applied damping pulse. After obtaining the α-axis voltage compensation component, it outputs it to the first addition unit. Based on the applied damping pulse and β-axis voltage, it obtains the β-axis voltage compensation component. When the β-axis voltage is above a preset voltage, the β-axis voltage compensation component is the negative of the applied damping pulse; when the β-axis voltage is below the preset voltage, the β-axis voltage compensation component is the applied damping pulse. After obtaining the β-axis voltage compensation component, it outputs it to the second addition unit.

[0133] The first addition unit obtains the α-axis voltage and the α-axis voltage compensation component, then superimposes the α-axis voltage compensation component onto the α-axis voltage to obtain the α-axis voltage command, and applies the α-axis voltage command to the space vector pulse width modulation (SVPWM) inverter. The second addition unit obtains the β-axis voltage and the β-axis voltage compensation component, then superimposes the β-axis voltage compensation component onto the β-axis voltage to obtain the β-axis voltage command, and applies the β-axis voltage command to the space vector pulse width modulation (SVPWM) inverter.

[0134] In an exemplary embodiment, this application also provides a current harmonic suppression device, which may include one or more functional modules for implementing a current harmonic suppression method for an electrolytic capacitor-free drive system according to the above method embodiments.

[0135] For example, Figure 10 This is a schematic diagram illustrating the composition of a current harmonic suppression device provided in an embodiment of this application. Figure 10 As shown, the current harmonic suppression device 100 includes: an acquisition unit 1001, a comparator unit 1002, an amplification and operation unit 1003, a phase operation unit 1004, a damping voltage generation unit 1005, a first addition operation unit 1006, and a second addition operation unit 1007.

[0136] Acquisition unit 1001 is used to acquire the same frequency sawtooth wave U. sawtooth Same frequency sawtooth wave U sawtooth It is generated based on the LC resonant frequency.

[0137] Comparator unit 1002 is used to convert the sawtooth wave U of the same frequency sawtooth and sawtooth wave given value U constant By comparison, the rectangular wave U is obtained. rectangular .

[0138] Amplification unit 1003 is used to amplify the rectangular wave U rectangular Amplification is performed to obtain the given damped pulse.

[0139] Phase calculation unit 1004 is used to process a given damping pulse based on the three-phase current on the grid side. A phase shift is performed to obtain the applied damping pulse U. pulse .

[0140] In some embodiments, the phase operation unit 1004 is specifically used for: performing time detection on the grid-side three-phase current to obtain the time when the grid-side three-phase current is at a trough; and performing phase shift on a given damping pulse based on the time when the grid-side three-phase current is at a trough to obtain the applied damping pulse.

[0141] Damping voltage generation unit 1005, used to generate voltage based on applied damping pulse U pulse The α-axis voltage compensation component ΔU is obtained. α and β-axis voltage compensation component ΔU β .

[0142] In some embodiments, the damping voltage generating unit 1005 is specifically configured to: generate voltage according to the applied damping pulse U pulse and α-axis voltage U αThe α-axis voltage compensation component ΔU is obtained. α According to the applied damping pulse U pulse and β-axis voltage U β The β-axis voltage compensation component ΔU is obtained. β .

[0143] In some embodiments, the damping voltage generating unit 1005 is specifically used for: if the α-axis voltage U α Determine the α-axis voltage compensation component ΔU above the preset voltage. α The negative number U of the applied damping pulse pulse If the α-axis voltage U α Below the preset voltage, determine the α-axis voltage compensation component ΔU. α For the applied damping pulse U pulse ;

[0144] If the β-axis voltage U β Determine the β-axis voltage compensation component ΔU above the preset voltage. β For the applied damping pulse U pulse The negative number; if the β-axis voltage U β Determine the β-axis voltage compensation component ΔU below the preset voltage. β For the applied damping pulse U pulse .

[0145] The first addition unit 1006 is used to process the α-axis voltage compensation component ΔU. α Superimposed on the α-axis voltage U α Above, the α-axis voltage command is obtained. α-axis voltage command Output to SVPWM inverter.

[0146] The second addition unit 1007 is used to process the β-axis voltage compensation component ΔU. β Superimposed on the β-axis voltage U β Above, the β-axis voltage command is obtained. β-axis voltage command Output to SVPWM inverter.

[0147] In the case of implementing the functions of the integrated modules described above in hardware, this application embodiment also provides a hardware structure diagram of a current harmonic suppression device, which can be the aforementioned current harmonic suppression device 100, such as... Figure 11 As shown, the current harmonic suppression device 3000 includes a processor 3001, and optionally, a memory 3002 and a communication interface 3003 connected to the processor 3001. The processor 3001, memory 3002 and communication interface 3003 are connected via a bus 3004.

[0148] Processor 3001 may be a central processing unit (CPU), a general-purpose processor, a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. Processor 3001 may also be any other device with processing capabilities, such as a circuit, device, or software module. Processor 3001 may also include multiple CPUs, and processor 3001 may be a single-core processor or a multi-core processor. Here, "processor" may refer to one or more devices, circuits, or processing cores used to process data (e.g., computer program instructions).

[0149] The memory 3002 can be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions. It can also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), a magnetic disk storage medium, or other magnetic storage device, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer. This application embodiment does not impose any limitations on this. The memory 3002 can exist independently or be integrated with the processor 3001. The memory 3002 may contain computer program code. The processor 3001 executes the computer program code stored in the memory 3002 to implement the current harmonic suppression method for the electrolytic capacitor-free drive system provided in this application embodiment.

[0150] The communication interface 3003 can be used to communicate with other devices or communication networks (such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc.). The communication interface 3003 can be a module, circuit, transceiver, or any device capable of enabling communication.

[0151] Bus 3004 can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. Bus 3004 can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 11 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0152] This application also provides a computer-readable storage medium including computer-executable instructions that, when run on a computer, cause the computer to perform any of the methods provided in the above embodiments.

[0153] This application also provides a computer program product containing computer execution instructions, which, when run on a computer, causes the computer to perform any of the methods provided in the above embodiments.

[0154] This application also provides a chip, including a processor and an interface. The processor is coupled to a memory through the interface. When the processor executes a computer program in the memory or computer execution instructions, any of the methods provided in the above embodiments are executed.

[0155] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software programs, implementation can be, in whole or in part, in the form of a computer program product. This computer program product includes one or more computer-executable instructions. When these computer-executable instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer-executable instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer-executable instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device containing one or more servers, data centers, etc., that can be integrated with the medium. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state disks, SSDs).

[0156] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings, the disclosure, and the appended claims, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple instances. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0157] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of this application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from the spirit and scope of this application. Thus, if such modifications and modifications of this application fall within the scope of the claims of this application and their equivalents, this application is also intended to include such modifications and modifications.

[0158] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A current harmonic suppression method for an electrolytic capacitor-less driving system, characterized by, include: Obtain a sawtooth wave of the same frequency, which is generated based on the LC resonant frequency; The same-frequency sawtooth wave and the given value of the sawtooth wave are compared to obtain a rectangular wave, and the rectangular wave is amplified to obtain a given damping pulse; The time when the three-phase current on the grid side is located at the trough is obtained by performing time detection on the three-phase current on the grid side. Based on the time when the three-phase current on the grid side is at its trough, the phase of the given damping pulse is shifted to obtain the applied damping pulse; Based on the applied damping pulse, the α-axis voltage compensation component and the β-axis voltage compensation component are obtained; The α-axis voltage compensation component is superimposed on the α-axis voltage to obtain the α-axis voltage command; The β-axis voltage compensation component is superimposed on the β-axis voltage to obtain the β-axis voltage command; The α-axis voltage command and the β-axis voltage command are applied to the space vector pulse width modulation (SVPWM) inverter.

2. The method of claim 1, wherein, The step of obtaining the α-axis voltage compensation component and the β-axis voltage compensation component based on the applied damping pulse includes: The α-axis voltage compensation component is obtained based on the applied damping pulse and the α-axis voltage. The β-axis voltage compensation component is obtained based on the applied damping pulse and the β-axis voltage.

3. The method according to claim 2, characterized in that, The step of obtaining the α-axis voltage compensation component based on the applied damping pulse and the α-axis voltage includes: If the α-axis voltage is greater than or equal to a preset voltage, the α-axis voltage compensation component is determined to be the negative of the applied damping pulse; If the α-axis voltage is less than the preset voltage, the α-axis voltage compensation component is determined to be the applied damping pulse.

4. The method of claim 2, wherein, The β-axis voltage compensation component is obtained based on the applied damping pulse and the β-axis voltage: If the β-axis voltage is greater than or equal to a preset voltage, the β-axis voltage compensation component is determined to be the negative of the applied damping pulse; If the β-axis voltage is less than the preset voltage, the β-axis voltage compensation component is determined to be the applied damping pulse.

5. A current harmonic suppression device, characterized by, include: An acquisition unit is used to acquire a sawtooth wave of the same frequency, which is generated based on the LC resonant frequency. The comparator unit is used to compare the sawtooth wave of the same frequency with the given value of the sawtooth wave to obtain a rectangular wave; An amplification unit is used to amplify the rectangular wave to obtain a given damping pulse; The phase calculation unit is used to perform time detection on the grid-side three-phase current to obtain the time when the grid-side three-phase current is located at the trough. Based on the time when the three-phase current on the grid side is at its trough, the phase of the given damping pulse is shifted to obtain the applied damping pulse; A damping voltage generation unit is used to obtain the α-axis voltage compensation component and the β-axis voltage compensation component based on the applied damping pulse. The first addition unit is used to superimpose the α-axis voltage compensation component onto the α-axis voltage to obtain the α-axis voltage command, and output the α-axis voltage command to the SVPWM inverter; The second addition unit is used to superimpose the β-axis voltage compensation component onto the β-axis voltage to obtain the β-axis voltage command, and output the β-axis voltage command to the SVPWM inverter.

6. The apparatus according to claim 5, characterized in that, The damping voltage generation unit is specifically used to: obtain the α-axis voltage compensation component based on the applied damping pulse and the α-axis voltage; and obtain the β-axis voltage compensation component based on the applied damping pulse and the β-axis voltage.

7. The apparatus according to claim 6, characterized in that, The damping voltage generation unit is specifically used to: if the α-axis voltage is greater than or equal to a preset voltage, determine that the α-axis voltage compensation component is the negative number of the applied damping pulse; If the α-axis voltage is less than the preset voltage, the α-axis voltage compensation component is determined to be the applied damping pulse; If the β-axis voltage is greater than or equal to a preset voltage, the β-axis voltage compensation component is determined to be the negative of the applied damping pulse; If the β-axis voltage is less than the preset voltage, the β-axis voltage compensation component is determined to be the applied damping pulse.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes computer instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1 to 4.

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