A high-frequency harmonic suppression method based on a motor control system

Abstract

The application relates to a high-frequency harmonic suppression method based on a motor control system, in particular to the technical field of motor control, and comprises the following steps: S1, calculating a modulation rate according to collected motor rotating speeds; S2, comparing the collected motor rotating speeds with preset motor rotating speeds n1, and taking different modes to suppress high-frequency harmonics according to comparison results; S3, when the motor rotating speed is less than n1, a random switching frequency method is used to suppress high-frequency harmonics in an asynchronous modulation mode; S4, when the motor rotating speed is greater than or equal to n1 and the modulation rate is less than a preset modulation rate k1, a random zero vector method is used to suppress high-frequency harmonics; and S5, when the motor rotating speed is greater than or equal to n1 and the modulation rate is greater than or equal to k1, an SVPWM method is used to suppress high-frequency harmonics. Different harmonic suppression modes are set according to different scenes, and the efficiency of suppressing harmonics is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor control, and particularly relates to a high-frequency harmonic suppression method based on a motor control system. BACKGROUND

[0002] In the field of motor control, the space vector pulse width modulation technology is widely used at present, but the deterministic modulation method also introduces harmonics into the control system. The generated harmonics are mainly concentrated near the integer multiples of the carrier frequency, which can easily cause problems such as electromagnetic radiation and mechanical vibration. In the prior art, only a single high-frequency harmonic is suppressed, for example, only the random switching frequency technology or the random zero vector technology is adopted, and different harmonic suppression technologies are not combined under different motor operating conditions, so the advantages of different technologies are not fully utilized.

[0003] Chinese Patent Publication No. CN108258947A discloses a method for suppressing high-frequency noise of an electric vehicle motor controller. The method controls the switching frequency of an IGBT drive module according to the motor speed and torque signals to suppress high-frequency noise. In some operating conditions, the random carrier frequency technology is used, but other harmonic suppression technologies are not combined, so the suppression effect is limited, and the harmonic suppression efficiency is low. SUMMARY

[0004] Therefore, the present application provides a high-frequency harmonic suppression method based on a motor control system to overcome the problem of low harmonic suppression efficiency in the prior art.

[0005] To achieve the above-mentioned purpose, in one aspect, the present application provides a high-frequency harmonic suppression method based on a motor control system, comprising:

[0006] Step S1: calculating a modulation rate according to the collected motor speed;

[0007] Step S2: comparing the collected motor speed with a preset motor speed n1, and taking different ways to suppress high-frequency harmonics according to the comparison result;

[0008] Step S3: when the motor speed is less than n1, using an asynchronous modulation method to apply a random switching frequency method to suppress high-frequency harmonics;

[0009] Step S4: when the motor speed is greater than or equal to n1, and the modulation rate is less than a preset modulation rate k1, using a random zero vector method to suppress high-frequency harmonics;

[0010] Step S5: when the motor speed is greater than or equal to n1, and the modulation rate is greater than or equal to k1, using an SVPWM method to suppress high-frequency harmonics.

[0011] Further, in the step S1, the modulation rate represents the amplitude of the motor stator voltage vector, which is defined as follows: let the motor stator voltage vector be V, the motor speed be n, the carrier frequency be f, and the modulation rate be m, then

[0012]

[0013] In the formula, m is the modulation rate, |u s | is the voltage vector amplitude, u d is the bus voltage amplitude.

[0014] Further, in the step S3, when the motor speed is less than n1, a random switching frequency method is applied, at this time, the switching frequency fluctuates around the reference switching frequency f0, the frequency range of fluctuation is represented as [f0-a, f0+b], the carrier switching frequency working interval of the IGBT tube in the inverter is defined as [f min ,f max ], when the random switching frequency method is used, the control [f0-a, f0+b] is in the frequency interval [f min ,f max ], wherein a is the first preset fluctuation difference, 0 min is the preset minimum carrier switching frequency, f max is the preset maximum carrier switching frequency.

[0015] Further, the random switching frequency method comprises: generating a random number by a random number generation module, and generating a random switching frequency F re_rdm by a random switching frequency generation module according to the generated random number and the reference switching frequency f0, so as to adjust the switching frequency of the motor control system and suppress high-frequency noise.

[0016] Further, in the step S4, the random zero vector method is to change the action time of the zero vector while ensuring that the effective voltage vector action time remains unchanged, and the matching of the two zero vectors V0 and V7 is randomly changed, and in the same switching cycle, the action time of the zero vector in the first half cycle and the second half cycle is equal.

[0017] Further, the proportion of the V0 vector to the two zero vectors is defined as K _0_7 , then the action time of the two zero vectors can be represented as follows, it is set that,

[0018] T0=K _0_7 ×T 07

[0019] T7=(1-K _0_7 )×T 07

[0020] In the formula, T0 represents the action time of the V0 vector, T7 represents the action time of the V7 vector, and T 07 represents the total action time of the zero vector.

[0021] Further, in the step S5, when the motor speed is greater than n1, the switching frequency varies with the motor speed, and when the modulation rate is large, the zero vector acting time is short, and the harmonic suppression effect is limited, so the SVPWM scheme is adopted to ensure the control stability.

[0022] In another aspect, the application also provides a motor control system, comprising:

[0023] An instruction receiving module is configured to receive a torque instruction sent by a VCU;

[0024] An instruction calculating module is configured to convert the torque instruction value into a d-axis current instruction value I d_cmd and a q-axis current instruction value I q_cmd .

[0025] A first PI control module is configured to output a q-axis voltage instruction u q , wherein the q-axis current instruction I q_cmd is input into the first PI control module after being subtracted from an actual q-axis current I q_value .

[0026] A second PI control module is configured to output a d-axis voltage instruction u d , wherein the d-axis current instruction I d_cmd is input into the second PI control module after being subtracted from an actual d-axis current I d_value .

[0027] A forward transformation module is configured to perform coordinate transformation on the input d-axis and q-axis voltage instructions, to transform the d-axis voltage instruction into an Alfa-axis voltage instruction u α and transform the q-axis voltage instruction into a Beta-axis voltage instruction u β .

[0028] An SVPWM module is configured to output the input Alfa-axis and Beta-axis voltage instructions as 6-path PWM duty cycle instructions.

[0029] An inverter module is internally provided with 6 power devices, and the 6-path PWM duty cycle instructions output by the SVPWM module are used to control the turn-on and turn-off of the 6 power devices, so as to control the motor module to output a target torque.

[0030] A first sensing module is configured to collect a rotor position θ of the motor.

[0031] A second sensing module is configured to collect a motor speed ω.

[0032] A reverse transformation module is configured to transform three-phase currents I u_value , I v_value and I w_value of the motor into d-axis and q-axis currents.By stationary coordinate system transformation to rotating coordinate system, get d-axis current I d_value And q-axis current I q_value .

[0033] Further, the motor control system further comprises:

[0034] Random number generation module, to generate random numbers;

[0035] Random switching frequency generation module, to generate random switching frequency F re_rdm According to the generated random number and the reference switching frequency f0, the switching frequency of the motor control system is adjusted.

[0036] Further, the motor control system further comprises:

[0037] Random zero vector module, to generate two zero vector proportion signals according to the generated random number, and transmit to the SVPWM module.

[0038] Compared with the prior art, the beneficial effects of the present application are that when the high frequency harmonic is suppressed, the motor speed is collected to take different suppression methods, when the motor speed is within the preset value, the random switching frequency method is used to suppress the high frequency harmonic, when the motor speed is above the preset value, different suppression methods are selected according to the value of the modulation rate, when the motor speed is greater than n1, the switching frequency changes with the speed, so the random switching frequency method is not used, if the modulation rate is within the preset value, the random zero vector method is used to suppress the high frequency harmonic, if the modulation rate is above the preset value, the SVPWM method is used to suppress the high frequency harmonic, when the modulation rate is large, the zero vector action time is short, the harmonic suppression effect is limited, the SVPWM method can effectively ensure the control stability, the present application sets different harmonic suppression methods for different scenes, effectively improves the efficiency of harmonic suppression.

[0039] Especially, the system converts the received torque instruction into current instruction values of each shaft through the instruction calculation module, so as to change the operation of the motor by transmitting electric signals to the motor, the application sets two PI control modules to convert the current instructions of different shafts to generate corresponding voltage instructions, and the current instruction is subtracted from the actual current value before being input into the PI control module, so that the converted voltage instruction is more accurate, and after obtaining the voltage instructions of each shaft, the coordinate axes of the voltage instructions are changed through coordinate transformation to obtain the voltage instructions of the Alpha shaft and the Beta shaft, and then the voltage instructions of the Alpha shaft and the Beta shaft are input into the SVPWM module to obtain 6-way PWM duty cycle instructions, so as to control the turn-on and turn-off of the 6 power devices in the inverter to control the motor output target torque, the switching state of the three-phase bridge arm switch tube is controlled through the SVPWM module to synthesize the target voltage vector, and then the three-phase voltage of the motor is controlled, which can effectively suppress the generated high-frequency harmonic, at the same time, the application also generates a random switching frequency through the random switching frequency generation module to adjust the switching frequency of the motor control system, thereby improving the efficiency of high-frequency harmonic suppression, and the application also generates two zero vector proportion signals according to the generated random number through the random zero vector module, and transmits them to the SVPWM module 9 to change the ratio of the two zero vectors when the SVPWM module works, thereby improving the efficiency of high-frequency harmonic suppression, the application adopts different ways to suppress harmonics under different conditions through the SVPWM module, the random switching frequency generation module and the random zero vector module, which can effectively improve the efficiency of high-frequency harmonic suppression. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 It is a structure schematic diagram of the motor control system of the embodiment;

[0041] Figure 2 It is a structure schematic diagram of the random number generation module and the random switching frequency generation module of the embodiment;

[0042] Figure 3 It is a structure schematic diagram of the random zero vector module of the embodiment;

[0043] Figure 4 It is a flowchart of the high-frequency harmonic suppression method based on the motor control system of the embodiment. DETAILED DESCRIPTION

[0044] In order to make the purpose and advantages of the application more clear and obvious, the application will be further described below in combination with the embodiments; it should be understood that the specific embodiments described herein are only used to explain the application, and do not limit the application.

[0045] The preferred embodiments of the present application will be described below with reference to the drawings. Those skilled in the art will appreciate that the embodiments are only used to explain the technical principles of the present application, and are not intended to limit the scope of protection of the present application.

[0046] In addition, it should be noted that, in the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "linking" should be understood in a broad sense, for example, can be fixed connection, or detachable connection, or integrally connected; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. Those skilled in the art can understand the specific meaning of the above terms in the present application according to the specific circumstances.

[0047] Please refer to Figure 1 The motor control system of the embodiment is shown in the figure, which comprises:

[0048] The instruction receiving module 5 is used to receive the torque instruction sent by the VCU;

[0049] The instruction calculation module 6 is used to convert the torque instruction value into the d-axis current instruction value I d_cmd and the q-axis current instruction value I q_cmd In the embodiment, the conversion process of the torque instruction value is not specifically limited, and those skilled in the art can freely set, such as through formula calculation or table lookup according to the pre-completed calibration results, as long as the conversion requirement is met;

[0050] The first PI control module 71 is used to output the q-axis voltage instruction u q , wherein the q-axis current instruction I q_cmd is input to the first PI control module 71 after being subtracted from the actual value I q_value of the q-axis current; in the embodiment, the first PI control module adopts conventional PI control, which is calculated through a proportional link and an integral link;

[0051] The second PI control module 72 is used to output the d-axis voltage instruction u d , wherein the d-axis current instruction I d_cmd is input to the second PI control module 72 after being subtracted from the actual value I d_value of the d-axis current; in the embodiment, the second PI control module adopts conventional PI control, which is calculated through a proportional link and an integral link;

[0052] The forward transformation module 8 is used to perform coordinate transformation on the input d, q-axis voltage instructions, to transform the d-axis voltage instruction into the Alpha-axis voltage instruction u α , and to transform the q-axis voltage instruction into the Beta-axis voltage instruction u β ;

[0053] SVPWM module 9, used to output the input Alpha, Beta axis voltage command as 6-way PWM duty ratio command; in this embodiment, the SVPWM module adopts the traditional space vector pulse width modulation technical solution, that is, by controlling the switching state of the three-phase bridge arm switching tube, to synthesize the target voltage vector, and then control the three-phase voltage of the motor;

[0054] Inverter module 2, which is internally provided with 6 power devices, controls the turn-on and turn-off of the 6 power devices through the 6-way PWM duty ratio command output by the SVPWM module, so as to control the motor module 1 to output the target torque;

[0055] First sensing module 10, used to collect the rotor position θ of the motor;

[0056] Second sensing module 3, used to collect the speed ω of the motor;

[0057] Reverse transformation module 4, used to transform the three-phase current I u_value , I v_value and I w_value from the stationary coordinate system to the rotating coordinate system, to obtain the d-axis current I d_value and the q-axis current I q_value .

[0058] Please refer to Figure 2 , the motor control system further comprises:

[0059] Random number generation module 11, used to generate random numbers;

[0060] Random switching frequency generation module 12, used to generate random switching frequency F re_rdm according to the generated random number and the reference switching frequency f0 to adjust the switching frequency of the motor control system. In this embodiment, the random switching frequency generation module adopts the uniform random number generation method, that is, the random number generation module generates random numbers in a certain range with equal probability, and the random switching frequency generation module superimposes the random number on the reference switching frequency f0 to obtain the random switching frequency F re_rdm .

[0061] Please refer to Figure 3 , the motor control system further comprises:

[0062] Random zero vector module 13, used to generate two zero vector proportion signals according to the generated random number, and transmit to the SVPWM module 9 to change the ratio of two zero vectors V0 and V7 when the SVPWM module works.

[0063] Specifically, the system converts the received torque instruction through the instruction calculation module to obtain the current instruction value of each shaft, so as to change the operation of the motor by transmitting the electric signal to the motor. The two PI control modules are arranged to convert the current instruction of different shafts to generate corresponding voltage instructions. The difference between the current instruction and the actual current value is calculated before the current instruction is input into the PI control module, so that the converted voltage instruction is more accurate. After obtaining the voltage instruction of each shaft, the coordinate axis of the voltage instruction is changed through the coordinate transformation method to obtain the voltage instruction of the Alpha and Beta axes. Then, the voltage instructions of the Alpha and Beta axes are input into the SVPWM module to obtain 6 PWM duty cycle instructions, so as to control the turn-on and turn-off of the 6 power devices in the inverter to control the motor output target torque. The switching state of the three-phase bridge arm switch tube is controlled by the SVPWM module to synthesize the target voltage vector, thereby controlling the three-phase voltage of the motor. The generated high-frequency harmonics can be effectively suppressed. In addition, the random switching frequency generation module is arranged in the embodiment to generate a random switching frequency, so as to adjust the switching frequency of the motor control system, thereby improving the efficiency of high-frequency harmonic suppression. In addition, the random zero vector module is arranged to generate two zero vector proportion signals according to the generated random number, and transmit the two zero vector proportion signals to the SVPWM module 9 to change the ratio of the two zero vectors when the SVPWM module works, thereby improving the efficiency of high-frequency harmonic suppression. In the embodiment, the SVPWM module, the random switching frequency generation module and the random zero vector module are arranged to take different ways to suppress harmonics under different conditions, which can effectively improve the efficiency of high-frequency harmonic suppression.

[0064] Referring to Figure 4 The method for suppressing high-frequency harmonics of the motor control system comprises the following steps:

[0065] Step S1: calculating the modulation rate according to the collected motor speed;

[0066] Step S2: comparing the collected motor speed with the preset motor speed n1, and taking different ways to suppress high-frequency harmonics according to the comparison result;

[0067] Step S3: when the motor speed is less than n1, the random switching frequency method is used to suppress high-frequency harmonics in the asynchronous modulation mode;

[0068] Step S4: when the motor speed is greater than or equal to n1, and the modulation rate is less than the preset modulation rate k1, the random zero vector method is used to suppress high-frequency harmonics;

[0069] Step S5: when the motor speed is greater than or equal to n1, and the modulation rate is greater than or equal to k1, the SVPWM method is used to suppress high-frequency harmonics.

[0070] Specifically, in step S1, the modulation ratio represents the amplitude of the motor stator voltage vector, which is defined as follows, assuming that the modulation ratio is m,

[0071]

[0072] where m is the modulation ratio, |u s | is the voltage vector amplitude, u d is the bus voltage amplitude.

[0073] Specifically, in step S3, when the motor speed is less than n1, the random switching frequency method is applied, at which time the switching frequency fluctuates around the reference switching frequency f0, and the fluctuation frequency range is represented as [f0-a, f0+b], and the carrier switching frequency operating interval of the IGBT tube in the inverter is defined as [f min ,f max ], when the random switching frequency method is used, [f0-a, f0+b] is controlled within the frequency interval [f min ,f max ], where a is a first preset fluctuation difference, 0 min is a preset minimum carrier switching frequency, and f max is a preset maximum carrier switching frequency.

[0074] The random switching frequency method includes generating a random number by a random number generation module 11, and generating a random switching frequency F re_rdm by a random switching frequency generation module 12 according to the generated random number and the reference switching frequency f0, to adjust the switching frequency of the motor control system and suppress high-frequency noise. The random switching frequency method directly changes the switching frequency of the motor control system to disperse the switching frequency range, thereby suppressing the harmonic content in the three-phase current.

[0075] Specifically, in step S4, the random zero vector method changes the action time of the zero vector while keeping the effective voltage vector action time unchanged, and randomly changes the ratio of two zero vectors V0 and V7, and the action time of the zero vector in the first half cycle and the second half cycle is equal in the same switching cycle.

[0076] The proportion of V0 vector to two zero vectors is defined as K _0_7 , and the action time of the two zero vectors can be represented as follows, assuming that

[0077] T0=K _0_7 ×T 07

[0078] T7=(1-K _0_7) x T 07

[0079] In the formula, T0 represents the action time of the V0 vector, T7 represents the action time of the V7 vector, and T represents the total action time of the zero vector. 07

[0080] Specifically, in the embodiment, when the modulation ratio is small, the action time of the zero vector is large, and the high-frequency harmonic suppression performance of the random zero vector method is good; when the modulation ratio is large, the action time of the zero vector is small, and the harmonic suppression performance of the strategy becomes poor, so when the modulation ratio is less than k1, the random zero vector method is used for harmonic suppression.

[0081] Specifically, in the step S5, when the motor speed is greater than n1, the switching frequency changes with the speed, so the random switching frequency method is not used, and when the modulation ratio is large, the action time of the zero vector is short, and the harmonic suppression effect is limited, so the traditional SVPWM scheme is used to ensure the control stability, and the zero vector is not randomized, that is, the switching state of the three-phase bridge arm switch tube is controlled to synthesize the target voltage vector, and then the three-phase voltage of the motor is controlled.

[0082] Specifically, the random switching frequency method and the random zero vector method are two commonly used random SVPWM methods, which have certain improvement effect on the high-frequency harmonics generated by the motor, but the use of the two methods has certain limitations. When the random switching frequency method is used, the system control carrier frequency fluctuates within a certain range, and when the motor control system needs to be synchronized, it cannot be applied. In the motor control system of the embodiment, when the motor speed is greater than or equal to n1, the synchronous modulation mode is used, that is, the switching frequency changes with the increase of the motor speed, so that the ratio of the switching frequency to the motor angular velocity remains the same in each speed range interval, and when the speed is less than n1, the asynchronous modulation mode is used.

[0083] Specifically, in the embodiment, when suppressing high-frequency harmonics, the motor speed is collected to adopt different suppression methods. When the motor speed is within the preset value, the random switching frequency method is used to suppress high-frequency harmonics, and when the motor speed is above the preset value, different suppression methods are selected according to the value of the modulation ratio. When the motor speed is greater than n1, the switching frequency changes with the speed, so the random switching frequency method is not used. If the modulation ratio is within the preset value, the random zero vector method is used to suppress high-frequency harmonics, and if the modulation ratio is above the preset value, the SVPWM method is used to suppress high-frequency harmonics. When the modulation ratio is large, the action time of the zero vector is short, and the harmonic suppression effect is limited, so the SVPWM method can effectively ensure the control stability. The embodiment sets different harmonic suppression methods for different scenarios, effectively improving the efficiency of harmonic suppression.

[0084] ​The technical scheme of the present application has been described in combination with the preferred embodiments shown in the drawings, but it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical schemes after the changes or replacements will all fall within the protection scope of the present application.

Claims

1. A method for high frequency harmonic suppression based on motor control system, characterized in that, Comprise: Step S1: collect the motor speed, and calculate the modulation rate; Step S2: compare the collected motor speed with the preset motor speed n1, and take different ways to suppress high frequency harmonics according to the comparison result; Step S3: when the motor speed is less than n1, the random switching frequency method is used to suppress high frequency harmonics by adopting asynchronous modulation mode; Step S4: when the motor speed is greater than or equal to n1, and the modulation rate is less than the preset modulation rate k1, the random zero vector method is used to suppress high frequency harmonics; Step S5: when the motor speed is greater than or equal to n1, and the modulation rate is greater than or equal to k1, the traditional SVPWM method is used to suppress high frequency harmonics.

2. The method of high frequency harmonic suppression based on motor control system according to claim 1, wherein, In step S1, the modulation rate is related to the amplitude of the motor stator voltage vector, which is defined as follows, set, where m is the modulation ratio, |u s | is the voltage vector amplitude, u d is the bus voltage amplitude.

3. The method of claim 1, wherein the motor control system is a permanent magnet synchronous motor control system. In the step S3, when the motor speed is less than n1, a random switching frequency method is applied, at this time, the switching frequency fluctuates around the reference switching frequency f0, the frequency range of fluctuation is represented as [f0-a, f0+b], the carrier switching frequency working interval of the IGBT tube in the inverter is defined as [f min ,f max ], when using the random switching frequency method, control [f0-a, f0+b] in the frequency interval [f min ,f max ], wherein a is a first preset fluctuation difference, 0 min is a preset minimum carrier switching frequency, f max is a preset maximum carrier switching frequency.

4. The method of high frequency harmonic suppression based on motor control system according to claim 3, wherein, The random switching frequency method includes generating a random number by a random number generation module, and generating a random switching frequency F by a random switching frequency generation module according to the generated random number and a reference switching frequency f0 re_rdm The switching frequency of the motor control system is adjusted, and high-frequency noise is suppressed.

5. The motor control system based high frequency harmonic mitigation method of claim 1, wherein, In step S4, the random zero vector method is to change the action time of zero vector while keeping the effective voltage vector action time unchanged, and randomly change the ratio of two zero vectors V0 and V7, and the action time of zero vector in the first half cycle and the second half cycle is equal in the same switching cycle.

6. The method of high frequency harmonic suppression based on motor control system according to claim 5, wherein, The proportion of the defined V0 vector to two zero vectors is K _0_7 , the action time of the two zero vectors can be expressed as follows, set T0 = K _0_7 x T 07 T7 = (1 - K _0_7 ) x T 07 wherein T0 represents the time of action of the V0 vector, T7 represents the time of action of the V7 vector, and T 07 represents the total time of action of the zero vector.

7. The motor control system based high frequency harmonic mitigation method of claim 1, wherein, In step S5, when the motor speed is greater than n1, the switching frequency changes with the speed, and when the modulation rate is large, the zero vector action time is short, and the harmonic suppression effect is limited, and the traditional SVPWM scheme is adopted to ensure the stability of control.

8. The method of high frequency harmonic suppression based on motor control system according to any one of claims 1-7, characterized in that, The motor control system comprises: The instruction receiving module is used to receive the torque instruction sent by the VCU; an instruction calculation module for converting the torque instruction value into a d-axis current instruction value I d_cmd and a q-axis current instruction value I q_cmd ; a first PI control module for outputting a q-axis voltage command u q wherein the q-axis current command I q_cmd is subtracted from the q-axis current actual value I q_value and the difference is input to the first PI control module. a second PI control module, configured to output a d-axis voltage instruction u d wherein the d-axis current instruction I d_cmd is obtained by subtracting the d-axis current actual value I d_value from the d-axis current reference value I a forward transformation module for performing coordinate transformation on input d, q-axis voltage commands to transform the d-axis voltage command into an Alfa-axis voltage command u α transforming the q-axis voltage command into a Beta-axis voltage command u β ; The SVPWM module is used to output the input Alfa, Beta axis voltage instruction as 6 road PWM duty ratio instruction; The inverter module is internally provided with 6 power devices, and the 6 road PWM duty ratio instruction output by the SVPWM module is used to control the turn-on and turn-off of the 6 power devices, so as to control the motor module to output the target torque; The first sensing module is used to collect the rotor position θ of the motor; The second sensing module is used to collect the motor speed ω; a reverse transformation module for transforming the three-phase current I u_value , v_value and I w_value of the motor from the stationary coordinate system into the rotating coordinate system to obtain the d-axis current I d_value and the q-axis current I q_value .

9. The motor control system based high frequency harmonic mitigation method of claim 8, wherein, The motor control system further comprises: The random number generation module is used to generate random numbers; a random switching frequency generation module for generating a random switching frequency F according to the generated random number and a reference switching frequency f0 re_rdm to adjust the switching frequency of the motor control system.

10. The method of high frequency harmonic suppression based on motor control system according to claim 9, wherein, The motor control system further comprises: The random zero vector module is used to generate the ratio signal of the two zero vectors according to the generated random numbers, and transmit it to the SVPWM module.

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