阅读说明：本技术 用于电动汽车逆变器的组合型无零矢量过调制方法 (Combined zero-vector-free overmodulation method for electric vehicle inverter ) 是由 吴平仿 黄洪剑 陈双 于 2019-10-28 设计创作，主要内容包括：本发明公开了一种用于电动汽车逆变器的组合型无零矢量过调制方法,本方法采用调制比分度的组合型无零矢量PWM过调制策略,计算调制比参数MI<Sub>1</Sub>、MI<Sub>2</Sub>、MI<Sub>3</Sub>、MI<Sub>4</Sub>,当调制比范围0≤MI<MI<Sub>1</Sub>,运行零矢量替代PWM调制,当调制比范围MI<Sub>1</Sub>≤MI<MI<Sub>2</Sub>,运行修正零矢量替代PWM调制,当调制比范围MI<Sub>2</Sub>≤MI<MI<Sub>3</Sub>,运行最近非零矢量合成PWM调制,当调制比范围MI<Sub>3</Sub>≤MI<MI<Sub>4</Sub>,运行最近非零矢量合成PWM第一过调制区方法,当调制比范围MI<Sub>4</Sub>≤MI<1,运行最近非零矢量合成PWM第二过调制区方法。本方法可在全调制比范围内降低共模电压峰值2/3,且能有效提高输出电压约10％,实现对共模电压峰值的抑制,提升逆变器输出电压和峰值功率的能力,减少系统的振动和噪音,提升整车NVH品质。(The invention discloses a combined zero-free vector overmodulation method for an electric vehicle inverter 1 、MI 2 、MI 3 、MI 4 When the modulation ratio is in the range of 0 ≦ MI<MI 1 Run zero vector instead of PWM modulation, when the modulation ratio is in range MI 1 ≤MI<MI 2 Running a modified zero vector instead of PWM modulation when the modulation ratio is in range MI 2 ≤MI<MI 3 Running the nearest non-zero vector composite PWM modulation when the modulation ratio is in range MI 3 ≤MI<MI 4 Operating the nearest non-zero vector composite PWM first overmodulation region method when the modulation ratio range MI 4 ≤MI<1, the nearest non-zero vector composite PWM second overmodulation region method is operated. The method can reduce the common mode voltage peak value 2/3 in the full modulation ratio range and effectively improve the outputThe voltage is about 10%, the suppression to the common mode voltage peak value is realized, the ability of inverter output voltage and peak power is promoted, the vibration and noise of the system are reduced, and the NVH quality of the whole vehicle is promoted.)

1. A combined zero-free vector overmodulation method for an electric vehicle inverter is characterized by comprising the following steps:

step one, setting a reference voltage vector V of PWM modulation_sLocated in the first sector, the synthesis of which is obtained according to equation (1),

wherein, T₁、T₂、T₃、T₆Are respectively a voltage vector V₁、V₂、V₃、V₆Time of action of (T)_zIs a PWM modulation period;

step two, adopting a synthetic voltage sequence and a PWM pulse action mode of a zero vector substitution PWM modulation method to realize PWM modulation output of zero vector substitution PWM modulation;

step three, replacing action time T of PWM modulation by zero vector₁、T₂、T₃、T₆Correcting to set the effective dead time of the inverter as T_dDefining a minimum correction time T_min＝2T_dThe corrected action times are respectively expressed by the formula (2) and the formula (3),

wherein, the position area of the voltage vector is 0-30 degrees in the formula (2), the position area of the voltage vector is 30-60 degrees in the formula (3), and u is_sα、u_sβIs a two-phase stationary frame voltage, U_DCIs a dc bus voltage;

step four, obtaining a constraint modulation ratio parameter MI while correcting the action time of the voltage vector₁And MI₂In which MI₂>MI₁When the modulation ratio is in the range of MI₁≤MI<MI₂The modified zero vector is adopted to replace PWM modulation, and MI is more than or equal to 0 when the modulation ratio range is<MI₁Adopting the original zero vector to replace PWM modulation;

step five, when the modulation ratio range exceeds MI₂Then, entering the nearest non-zero vector synthesis PWM modulation region, and setting a reference voltage vector V_sLocated in the second sector, the synthesis of which is obtained according to equation (4),

wherein, T₁、T₂、T₃Are respectively a voltage vector V₁、V₂、V₃Time of action of (T)_zIs a PWM modulation period;

step six, adopting a synthetic voltage sequence and a PWM pulse action mode of the latest non-zero vector synthetic PWM modulation method to realize the PWM modulation output of the latest non-zero vector synthetic PWM modulation method;

step seven, acting time T of PWM modulation method for latest non-zero vector synthesis₁、T₂、T₃Correcting to obtain the action time after correction as an expression (5),

wherein, the position area of the voltage vector is 30-60 degrees in the formula (5), and the modulation ratio range of the latest non-zero vector synthesis PWM modulation meeting the constraint condition is MI₂≤MI<MI₃，MI₃Is the linear modulation ratio boundary;

step eight, when the modulation ratio range of the recent non-zero vector synthesis PWM exceeds MI₃When the voltage vector crosses into the overmodulation region from the linear modulation region, dividing the recent non-zero vector synthesis PWM overmodulation into a first overmodulation region and a second overmodulation region, wherein the first overmodulation region adopts a stator voltage vector angle following strategy, and the second overmodulation region adopts a stator voltage vector angle progressive following strategy, so that the reference voltage vector angle is corrected;

the voltage vector angle of the first overmodulation region reference voltage vector in the first sector is corrected as:

wherein, V'_s1Reference voltage vector for the first overmodulation region, theta is parameterVector angle of reference voltage, α_rIs a control angle;

the first overmodulation region control angle has the following relation with the modulation ratio:

the voltage vector angle of the second overmodulation region reference voltage vector in the first sector is corrected as:

wherein, V'_s2Reference voltage vector for second overmodulation region, α_hTo maintain angle, θ'_rTo correct reference voltage vector angle, for θ'_rThe correction of (1) is as follows:

the holding angle of the second overmodulation region has the following relationship with the modulation ratio:

the control angle α can be found from the equations (7) and (10)_rMaintaining angle α in decreasing relation to modulation ratio MI_hIn increasing relation to the modulation ratio MI, when α_rWhen the angle is 30 °, formula (7) is substituted, and modulation ratio MI is calculated₃When α_hWhen the angle is 0 °, formula (10) is substituted, and modulation ratio MI is calculated₄，MI₄The boundary point of the first overmodulation region and the second overmodulation region is obtained;

step nine, calculating the sector where the voltage vector is located and the modulation ratio of the voltage vector according to the sector division rule by the latest non-zero vector synthesis PWM overmodulation, and if the modulation ratio is MI₃≤MI<MI₄Range according to a prestored control angle α_rRelation f (α) with modulation ratio MI_r) Calculating control angle α in real time_rCalculating a current voltage vector angle theta, and combining the current voltage vector angle theta with a path plan V 'of a voltage vector track in each sector'_s1Calculating the quadrature correction voltage f_α(θ)＝V'_s1cosθ、f_β(θ)＝V'_s1sin theta, calling a space voltage vector modulation algorithm to carry out three-phase duty ratio operation; if the modulation ratio is at MI₄≤MI<1 range according to a pre-stored hold angle α_hRelation f (α) to modulation ratio MI_h) Calculating the hold angle α in real time_hCalculating a corrected voltage vector angle θ'_rPlanning V 'of path in each sector by combining voltage vector tracks'_s2Calculating the quadrature correction voltage f_α(θ)＝V'_s2cosθ'_r、f_β(θ)＝V'_s2sinθ'_rAnd calling a space voltage vector modulation algorithm to carry out three-phase duty ratio operation.

Technical Field

The invention relates to the technical field of motor control, in particular to a combined zero-free vector overmodulation method for an electric vehicle inverter.

Background

The common-mode voltage output by the electric automobile motor driving inverter can generate shaft voltage on a rotating shaft of the permanent magnet synchronous motor through a coupling capacitor in the motor, and shaft current is generated at the same time to carry out electric corrosion on the bearing, so that the abrasion of the bearing is increased, the fault rate of the bearing is improved, and the service life of the bearing is reduced; and the common-mode interference phenomenon is accompanied, so that the vibration and noise output of the motor inverter system are increased. In order to reduce the peak value of the common-mode voltage and improve the reliability of the motor inverter system, the zero vector-free PWM modulation technology is utilized, the peak value of the common-mode voltage is restrained, and meanwhile, the common-mode interference can be reduced. On the premise, the instantaneous power peak value output by the inverter driven by the permanent magnet synchronous motor of the electric automobile needs to be improved as much as possible, and the short-time acceleration performance of the automobile is met, so that the maximum output voltage of the inverter needs to be improved, and the zero-vector PWM overmodulation technology can be used for solving the problem.

Disclosure of Invention

The invention aims to solve the technical problem of providing a combined zero-free vector overmodulation method for an electric vehicle inverter, which can effectively realize the suppression of a common-mode voltage peak value in a full modulation ratio range, improve the capacity of the output voltage and the peak power of the inverter, reduce the vibration and the noise of a system and improve the NVH quality of a whole vehicle.

In order to solve the technical problem, the combined zero-free vector overmodulation method for the electric vehicle inverter comprises the following steps:

step one, setting a reference voltage vector V of PWM modulation_sLocated in the first sector, the synthesis of which is obtained according to equation (1),

wherein, T₁、T₂、T₃、T₆Are respectively a voltage vector V₁、V₂、V₃、V₆Time of action of (T)_zIs a PWM modulation period;

step two, adopting a synthetic voltage sequence and a PWM pulse action mode of a zero vector substitution PWM modulation method to realize PWM modulation output of zero vector substitution PWM modulation;

step three, replacing action time T of PWM modulation by zero vector₁、T₂、T₃、T₆Correcting to set the effective dead time of the inverter as T_dDefining a minimum correction time T_min＝2T_dThe corrected action times are respectively expressed by the formula (2) and the formula (3),

wherein, the position area of the voltage vector is 0-30 degrees in the formula (2), the position area of the voltage vector is 30-60 degrees in the formula (3), and u is_sα、u_sβIs a two-phase stationary frame voltage, U_DCIs a dc bus voltage;

step four, obtaining a constraint modulation ratio parameter MI while correcting the action time of the voltage vector₁And MI₂In which MI₂>MI₁When the modulation ratio is in the range of MI₁≤MI<MI₂The modified zero vector is adopted to replace PWM modulation, and MI is more than or equal to 0 when the modulation ratio range is<MI₁Adopting the original zero vector to replace PWM modulation;

step five, when the modulation ratio range exceeds MI₂Then, entering the nearest non-zero vector synthesis PWM modulation region, and setting a reference voltage vector V_sLocated in the second sector, the synthesis of which is obtained according to equation (4),

wherein, T₁、T₂、T₃Are respectively a voltage vector V₁、V₂、V₃Time of action of (T)_zIs a PWM modulation period;

step six, adopting a synthetic voltage sequence and a PWM pulse action mode of the latest non-zero vector synthetic PWM modulation method to realize the PWM modulation output of the latest non-zero vector synthetic PWM modulation method;

step seven, acting time T of PWM modulation method for latest non-zero vector synthesis₁、T₂、T₃Correcting to obtain the action time after correction as an expression (5),

wherein, the position area of the voltage vector is 30-60 degrees in the formula (5), and the modulation ratio range of the latest non-zero vector synthesis PWM modulation meeting the constraint condition is MI₂≤MI<MI₃，MI₃Is the linear modulation ratio boundary;

step eight, when the modulation ratio range of the recent non-zero vector synthesis PWM exceeds MI₃When the voltage vector crosses into the overmodulation region from the linear modulation region, dividing the recent non-zero vector synthesis PWM overmodulation into a first overmodulation region and a second overmodulation region, wherein the first overmodulation region adopts a stator voltage vector angle following strategy, and the second overmodulation region adopts a stator voltage vector angle progressive following strategy, so that the reference voltage vector angle is corrected;

the voltage vector angle of the first overmodulation region reference voltage vector in the first sector is corrected as:

wherein, V'_s1Reference voltage vector for first overmodulation region, theta is reference voltage vector angle, α_rIs a control angle;

the first overmodulation region control angle has the following relation with the modulation ratio:

the voltage vector angle of the second overmodulation region reference voltage vector in the first sector is corrected as:

wherein, V'_s2Reference voltage vector for second overmodulation region, α_hTo maintain angle, θ'_rTo correct reference voltage vector angle, for θ'_rThe correction of (1) is as follows:

the holding angle of the second overmodulation region has the following relationship with the modulation ratio:

the control angle α can be found from the equations (7) and (10)_rMaintaining angle α in decreasing relation to modulation ratio MI_hIn increasing relation to the modulation ratio MI, when α_rWhen the angle is 30 °, formula (7) is substituted, and modulation ratio MI is calculated₃When α_hWhen the angle is 0 °, formula (10) is substituted, and modulation ratio MI is calculated₄，MI₄The boundary point of the first overmodulation region and the second overmodulation region is obtained;

step nine, calculating the sector where the voltage vector is located and the modulation ratio of the voltage vector according to the sector division rule by the latest non-zero vector synthesis PWM overmodulation, and if the modulation ratio is MI₃≤MI<MI₄Range according to a prestored control angle α_rRelation f (α) with modulation ratio MI_r) Calculating control angle α in real time_rCalculating a current voltage vector angle theta, and combining the current voltage vector angle theta with a path plan V 'of a voltage vector track in each sector'_s1Calculating the quadrature correction voltage f_α(θ)＝V'_s1cosθ、f_β(θ)＝V'_s1sin theta, calling a space voltage vector modulation algorithm to carry out three-phase duty ratio operation; if the modulation ratio is at MI₄≤MI<1 range according to a pre-stored hold angle α_hRelation f (α) to modulation ratio MI_h) Calculating the hold angle α in real time_hCalculating a corrected voltage vector angle θ'_rCombined with voltage vectorPath planning V 'of measurement track in each sector'_s2Calculating the quadrature correction voltage f_α(θ)＝V'_s2cosθ'_r、f_β(θ)＝V'_s2sinθ'_rAnd calling a space voltage vector modulation algorithm to carry out three-phase duty ratio operation.

The combined zero-free vector overmodulation method for the electric vehicle inverter adopts the technical scheme, namely, the method adopts a combined zero-free vector PWM overmodulation strategy of modulation ratio graduation to calculate the modulation ratio parameter MI₁、MI₂、MI₃、MI₄When the modulation ratio is in the range of 0 ≦ MI<MI₁Run zero vector instead of PWM modulation, when the modulation ratio is in range MI₁≤MI<MI₂Running a modified zero vector instead of PWM modulation when the modulation ratio is in range MI₂≤MI<MI₃Running the nearest non-zero vector composite PWM modulation when the modulation ratio is in range MI₃≤MI<MI₄Operating the nearest non-zero vector composite PWM first overmodulation region method when the modulation ratio range MI₄≤MI<1, the nearest non-zero vector composite PWM second overmodulation region method is operated. The method can reduce the common-mode voltage peak value 2/3 in the full modulation ratio range, effectively improve the output voltage by about 10%, realize the inhibition of the common-mode voltage peak value, improve the output voltage and peak power capability of the inverter, reduce the vibration and noise of the system and improve the NVH quality of the whole vehicle.

Drawings

The invention is described in further detail below with reference to the following figures and embodiments:

FIG. 1 is a schematic diagram of sector division of zero vector replacement PWM modulation in the method;

FIG. 2 is a schematic diagram of the zero vector replacement PWM modulation of the first sector pulse action mode and common mode voltage in the present method;

FIG. 3 is a schematic diagram of the sector division of the nearest non-zero vector synthesis PWM modulation in the present method;

FIG. 4 is a schematic diagram of the pulse mode and common mode voltage of the nearest non-zero vector synthesized PWM modulated first sector in the method;

FIG. 5 is a schematic diagram of a voltage vector trajectory of a most recent non-zero vector synthesized PWM overmodulation first overmodulation region in the present method;

FIG. 6 is a schematic diagram of a voltage vector trajectory for a second overmodulation region of recent non-zero vector synthesis PWM overmodulation in the present method;

fig. 7 is a schematic diagram of the relationship between the recent non-zero vector composite PWM overmodulation control angle/hold angle and the modulation ratio in the present method.

Fig. 8 is a flow chart of the PWM modulation strategy of the present method.

Detailed Description

The invention relates to a combined zero-free vector overmodulation method for an electric automobile inverter, which comprises the following steps:

step one, as shown in fig. 1, setting a reference voltage vector V of PWM modulation_sLocated in the first sector, the synthesis of which is obtained according to equation (1),

wherein, T₁、T₂、T₃、T₆Are respectively a voltage vector V₁、V₂、V₃、V₆Time of action of (T)_zIs a PWM modulation period;

step two, adopting a synthetic voltage sequence and a PWM pulse action mode of a zero vector substitution PWM modulation method to realize PWM modulation output of zero vector substitution PWM modulation;

the method of voltage vector synthesis according to equation (1) is called zero vector replacement PWM, i.e. two non-zero opposite voltage vectors (e.g. V adjacent to the first sector) adjacent to the sector where the reference voltage vector is located are selected₃And V₆) Instead of the zero vector, the other resultant voltage vector of the sector in which the reference voltage vector is located is maintained (e.g., V of the first sector)₁And V₂)；

As shown in fig. 2, in the zero vector replacement PWM modulation, the PWM1, PWM3, PWM5 are the PWM of the inverter three-phase upper bridge; u. of_ao、u_bo、u_coThe voltage from the midpoint of the inverter to the negative of the direct current bus; u. of_ab、u_bc、u_caFor the output line voltage of the inverter, it can be seen from the figure that the common mode voltage peak u_cmvCan be reduced to +/-U _DC6, the common mode voltage peak value of the traditional space voltage vector modulation method is +/-U _DC2, compared with the traditional SVPWM modulation method, the common-mode voltage is reduced by 2/3;

step three, to avoid T in FIG. 2₂Smaller, U, V-phase PWM of the inverter can be switched simultaneously, so that the common-mode voltage suppression failure phenomenon is caused, and the action time T of zero vector substitution PWM modulation₁、T₂、T₃、T₆Performing a correction, called correcting zero vector to replace PWM, and setting the effective dead time of the inverter to be T_dDefining a minimum correction time T_min＝2T_dThe corrected action times are respectively expressed by the formula (2) and the formula (3),

wherein, the position area of the voltage vector is 0-30 degrees in the formula (2), the position area of the voltage vector is 30-60 degrees in the formula (3), and u is_sα、u_sβIs a two-phase stationary frame voltage, U_DCIs a dc bus voltage;

step four, obtaining a constraint modulation ratio parameter MI while correcting the action time of the voltage vector₁And MI₂In which MI₂>MI₁When the modulation ratio is in the range of MI₁≤MI<MI₂The modified zero vector is adopted to replace PWM modulation, and MI is more than or equal to 0 when the modulation ratio range is<MI₁Adopting the original zero vector to replace PWM modulation;

step five, when the modulation ratio range exceeds MI₂Then, enter the nearest non-zero vector synthesis PWM modulation region, as shown in FIG. 3, set the reference voltage vector V_sLocated in the second sector, the synthesis of which is obtained according to equation (4),

wherein, T₁、T₂、T₃Are respectively a voltage vector V₁、V₂、V₃Time of action of (T)_zIs a PWM modulation period;

step six, adopting a synthetic voltage sequence and a PWM pulse action mode of the latest non-zero vector synthetic PWM modulation method to realize the PWM modulation output of the latest non-zero vector synthetic PWM modulation method;

the method of voltage vector synthesis according to equation (4) is called the nearest non-zero vector synthesis PWM, i.e. three non-zero vectors are selected to synthesize the reference voltage vector, one being the non-zero vector of the sector in which the reference voltage vector is located (e.g. the second sector V)₂) And one each of the left and right non-zero voltage vectors (e.g., V) nearest to the non-zero vector₁And V₃)；

As shown in fig. 4, its common mode voltage peak u_cmvReduced to + -U _DC6, compared with the traditional SVPWM modulation method, the common-mode voltage is also reduced by 2/3;

step seven, avoiding T in figure 4₂Too small, the V, W phase bridge arm PWM of the inverter may be switched simultaneously, which causes the phenomenon of common mode voltage inhibition failure, and the action time T of the recent non-zero vector synthesis PWM modulation method₁、T₂、T₃Correcting to obtain the action time after correction as an expression (5),

wherein, the position area of the voltage vector is 30-60 degrees in the formula (5), and the modulation ratio range of the latest non-zero vector synthesis PWM modulation meeting the constraint condition is MI₂≤MI<MI₃，MI₃Is the linear modulation ratio boundary;

step eight, when the modulation ratio range of the recent non-zero vector synthesis PWM exceeds MI₃When the method enters the PWM overmodulation range of the latest non-zero vector compositionAfter the voltage vector crosses into the overmodulation region from the linear modulation region, dividing the recent non-zero vector synthesis PWM overmodulation into a first overmodulation region and a second overmodulation region, wherein the first overmodulation region adopts a stator voltage vector angle following strategy, and the second overmodulation region adopts a stator voltage vector angle progressive following strategy, as shown in FIGS. 5 and 6, wherein a thick solid line in the figures shows a track of the voltage vector, thereby correcting the reference voltage vector angle;

the voltage vector angle of the first overmodulation region reference voltage vector in the first sector is corrected as:

wherein, V'_s1Reference voltage vector for first overmodulation region, theta is reference voltage vector angle, α_rIs a control angle;

the first overmodulation region control angle has the following relation with the modulation ratio:

the voltage vector angle of the second overmodulation region reference voltage vector in the first sector is corrected as:

wherein, V'_s2Reference voltage vector for second overmodulation region, α_hTo maintain angle, θ'_rTo correct reference voltage vector angle, for θ'_rThe correction of (1) is as follows:

the holding angle of the second overmodulation region has the following relationship with the modulation ratio:

as can be seen from the equations (7) and (10), as shown in FIG. 7, the control angle α_rMaintaining angle α in decreasing relation to modulation ratio MI_hIn increasing relation to the modulation ratio MI, when α_rWhen the angle is 30 °, formula (7) is substituted, and modulation ratio MI is calculated₃When α_hWhen the angle is 0 °, formula (10) is substituted, and modulation ratio MI is calculated₄，MI₄The boundary point of the first overmodulation region and the second overmodulation region is obtained;

step nine, calculating the voltage vector located sector and the modulation ratio of the voltage vector according to the sector division rule shown in figure 2 by the latest non-zero vector synthesis PWM overmodulation, and if the modulation ratio is MI₃≤MI<MI₄Range according to a prestored control angle α_rRelation f (α) with modulation ratio MI_r) Calculating control angle α in real time_rCalculating the current voltage vector angle theta, and planning the path V of each sector by combining the voltage vector track_s'₁Calculating the quadrature correction voltage f_α(θ)＝V'_s1cosθ、f_β(θ)＝V'_s1sin theta, calling a space voltage vector modulation algorithm to carry out three-phase duty ratio operation; if the modulation ratio is at MI₄≤MI<1 range according to a pre-stored hold angle α_hRelation f (α) to modulation ratio MI_h) Calculating the hold angle α in real time_hCalculating a corrected voltage vector angle θ'_rPlanning V 'of path in each sector by combining voltage vector tracks'_s2Calculating the quadrature correction voltage f_α(θ)＝V'_s2cosθ'_r、f_β(θ)＝V'_s2sinθ'_rAnd calling a space voltage vector modulation algorithm to carry out three-phase duty ratio operation.

As shown in FIG. 8, the method adopts a combined zero-vector-free PWM overmodulation strategy and a low modulation ratio stage (MI is more than or equal to 0)<MI₁And MI₁≤MI<MI₂) PWM modulation strategy using zero vector substitution and modified zero vector substitution, medium modulation ratio phase (MI)₂≤MI<MI₃) PWM modulation strategy using recent non-zero vector synthesis, high modulation ratio stage (MI)₃≤MI<MI₄And MI₄≤MI<1) An overmodulation strategy using the most recent non-zero vector composite PWM includes a first overmodulation region and a second overmodulation region. Because the zero vector replacing PWM technology and the recent zero vector synthesizing PWM technology avoid the use of a zero voltage vector, the common mode voltage peak value output by the inverter can be effectively restrained, meanwhile, the recent non-zero vector synthesizing PWM technology can reduce the power loss of the inverter, and the recent non-zero vector synthesizing PWM overmodulation technology does not use a zero voltage vector, so that the common mode voltage can be effectively restrained, and the phase voltage peak value output by the inverter is also effectively improved. The formed combined zero-free vector PWM overmodulation method can realize the suppression of common-mode voltage in the full modulation ratio range and simultaneously improve the capacity of the output voltage of the inverter.

The method is applied to the motor inverter driving system of the electric automobile, can effectively realize the inhibition of the common-mode voltage peak value in the full modulation ratio range, and can also improve the capacity of the controller for outputting voltage and peak power. When the common-mode voltage is effectively suppressed, the common-mode current is reduced, the common-mode interference of a suppression system is obviously suppressed, the vibration and noise of the system are reduced, and the NVH quality of the whole vehicle is improved. Meanwhile, the shaft voltage and the shaft current of the motor are also reduced, thereby reducing the failure rate of the motor bearing. The over-modulation technology can realize the over-modulation function only by correcting the orthogonal voltage, and effectively improve the output voltage and the instantaneous power peak value of the motor controller, thereby improving the acceleration performance of the vehicle.