CN111244981A

CN111244981A - Method and device for restraining unbalance of three-phase current

Info

Publication number: CN111244981A
Application number: CN202010153341.8A
Authority: CN
Inventors: 杨宝川; 刘涛; 桑霖霖; 熊丽满; 李龙
Original assignee: Beijing CHJ Automobile Technology Co Ltd
Current assignee: Beijing CHJ Automobile Technology Co Ltd
Priority date: 2020-03-06
Filing date: 2020-03-06
Publication date: 2020-06-05

Abstract

The invention discloses a method and a device for restraining three-phase current unbalance, and relates to the technical field of permanent magnet synchronous motors. The method of the invention comprises the following steps: acquiring a current three-phase current value corresponding to the permanent magnet synchronous motor, and converting the current three-phase current value into a current direct axis current calculated value and a current quadrature axis current calculated value; calculating a direct axis voltage instruction and a quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the current direct axis current calculated value and the current quadrature axis current calculated value, and calculating a direct axis voltage compensation quantity and a quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to the current direct axis current calculated value and the current quadrature axis current calculated value; calculating a target direct axis voltage instruction and a target quadrature axis voltage instruction according to the direct axis voltage instruction, the quadrature axis voltage instruction, the direct axis voltage compensation quantity and the quadrature axis voltage compensation quantity; and controlling the permanent magnet synchronous motor according to the target direct axis voltage instruction and the target quadrature axis voltage instruction. The method is suitable for the process of restraining the unbalance of the three-phase current of the permanent magnet synchronous motor.

Description

Method and device for restraining unbalance of three-phase current

Technical Field

The invention relates to the technical field of permanent magnet synchronous motors, in particular to a method and a device for restraining three-phase current unbalance.

Background

In recent years, with the continuous development of society, the living standard of people is continuously improved, the demand of people for automobiles is more and more, and electric automobiles powered by electric energy are produced due to the fact that the energy shortage and the environmental pollution problem caused by traditional automobiles are more and more serious. Because the permanent magnet synchronous motor has the advantages of a brushless structure, reliable operation and the like of the alternating current motor and the advantages of good speed regulation performance and the like of the direct current motor, the permanent magnet synchronous motor is widely applied to a driving system of an electric automobile. In order to ensure the three-phase current balance of the permanent magnet synchronous motor, the motor controller needs to detect the three-phase current value of the permanent magnet synchronous motor through the current sensor, detect the rotor position signal of the permanent magnet synchronous motor through the rotary transformer, and control the current output of the permanent magnet synchronous motor based on the three-phase current value and the rotor position signal obtained through detection.

However, since the current sensor has a temperature drift phenomenon, the three-phase current values detected and obtained by the current sensor are unbalanced; because the resolver may introduce an error of a frequency component in the production and assembly processes, a rotor position signal obtained by the resolver through detection may have an error, and the motor controller controls the current output of the permanent magnet synchronous motor based on an unbalanced three-phase current value and the rotor position signal having the error, which may further cause the unbalanced three-phase current of the permanent magnet synchronous motor, as shown in fig. 1. Therefore, how to suppress the occurrence of the phenomenon of unbalanced three-phase current of the permanent magnet synchronous motor caused by the temperature drift phenomenon of the current sensor and the production and assembly precision of the rotary transformer is a problem to be solved urgently.

Disclosure of Invention

In view of the above, the present invention provides a method and an apparatus for suppressing three-phase current imbalance, and mainly aims to suppress the occurrence of the phenomenon of three-phase current imbalance of a permanent magnet synchronous motor due to the temperature drift phenomenon of a current sensor and the production and assembly precision of a resolver.

In order to achieve the above purpose, the present invention mainly provides the following technical solutions:

in a first aspect, the present invention provides a method of suppressing a three-phase current imbalance, the method comprising:

acquiring a current three-phase current value corresponding to the permanent magnet synchronous motor, and converting the current three-phase current value into a current direct axis current calculated value and a current quadrature axis current calculated value;

calculating a direct axis voltage instruction and a quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the current direct axis current calculated value and the current quadrature axis current calculated value, and calculating a direct axis voltage compensation quantity and a quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to the current direct axis current calculated value and the current quadrature axis current calculated value;

calculating a target direct axis voltage instruction and a target quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the direct axis voltage instruction, the quadrature axis voltage instruction, the direct axis voltage compensation quantity and the quadrature axis voltage compensation quantity;

and controlling the permanent magnet synchronous motor according to the target direct axis voltage instruction and the target quadrature axis voltage instruction.

Optionally, the calculating a direct-axis voltage compensation amount and a quadrature-axis voltage compensation amount corresponding to the permanent magnet synchronous motor according to the current direct-axis current calculation value and the current quadrature-axis current calculation value includes:

carrying out high-pass filtering processing on the current direct-axis current calculated value and the current quadrature-axis current calculated value to obtain an alternating current component in the current direct-axis current and an alternating current component in the current quadrature-axis current corresponding to the permanent magnet synchronous motor;

carrying out phase compensation processing on the alternating current component in the current direct-axis current and the alternating current component in the current quadrature-axis current so as to obtain a same-frequency component of the current direct-axis current and a same-frequency component of the current quadrature-axis current corresponding to the permanent magnet synchronous motor;

calculating quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to a first preset proportionality coefficient and the same-frequency component of the current direct axis current, and calculating direct axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to a second preset proportionality coefficient and the same-frequency component of the current quadrature axis current.

Optionally, the performing high-pass filtering processing on the current direct-axis current calculated value and the current quadrature-axis current calculated value to obtain an alternating current component in the current direct-axis current and an alternating current component in the current quadrature-axis current corresponding to the permanent magnet synchronous motor includes:

acquiring a sampling calculation period, a first cut-off angle frequency corresponding to the permanent magnet synchronous motor, a historical direct axis current calculation value, a historical quadrature axis current calculation value, an alternating current component in historical direct axis current and an alternating current component in historical quadrature axis current;

substituting the sampling calculation period, the first cut-off angle frequency, the current direct-axis current calculation value, the historical direct-axis current calculation value and an alternating current component in the historical direct-axis current into a first preset algorithm to calculate the alternating current component in the current direct-axis current corresponding to the permanent magnet synchronous motor, wherein the first preset algorithm is as follows:

Y_n＝(X_n-X_n-1+Y_n-1)/(1+T_s*ω_c1)

wherein, Y_nFor the AC component in the present direct current, X_nCalculating a value, X, for said current direct axis current_n-1Calculating a value for said historical direct axis current, Y_n-1Is an alternating component in the historical direct current, T_sCalculating a period, ω, for said samples_c1Is the first cut-off angle frequency;

substituting the sampling calculation period, the first cut-off angle frequency, the current quadrature axis current calculation value, the historical quadrature axis current calculation value and an alternating component in the historical quadrature axis current into a second preset algorithm to calculate the alternating component in the current quadrature axis current corresponding to the permanent magnet synchronous motor, wherein the second preset algorithm is as follows:

Y_n＝(X_n-X_n-1+Y_n-1)/(1+T_s*ω_c1)

wherein, Y_nFor the AC component in the present quadrature-axis current, X_nCalculating a value, X, for said current quadrature axis current_n-1Calculating a value for said historical quadrature axis current, Y_n-1For the alternating component in the historical quadrature-axis current, T_sCalculating a period, ω, for said samples_c1Is the first cut-off angle frequency.

Optionally, the performing phase compensation processing on the alternating current component in the current direct-axis current and the alternating current component in the current quadrature-axis current to obtain a common-frequency component of the current direct-axis current and a common-frequency component of the current quadrature-axis current corresponding to the permanent magnet synchronous motor includes:

acquiring the number of pole pairs, the current revolution, the same-frequency component of historical direct-axis current and the same-frequency component of historical quadrature-axis current corresponding to the permanent magnet synchronous motor;

substituting the first cut-off angular frequency, the pole pair number and the current revolution number into a third preset algorithm to calculate a second cut-off angular frequency corresponding to the permanent magnet synchronous motor, wherein the third preset algorithm is as follows:

ω_c2＝ω_e ²/ω_c1ω_e＝(2π*P*n)/60

wherein, ω is_c2Is said second cut-off angular frequency, ω_c1The first cutoff angular frequency is defined as P, the number of pole pairs and n, the current number of revolutions;

substituting the sampling calculation period, the second cut-off angle frequency, the alternating current component in the current direct-axis current and the same-frequency component of the historical direct-axis current into a fourth preset algorithm to calculate the same-frequency component of the current direct-axis current corresponding to the permanent magnet synchronous motor, wherein the fourth preset algorithm is as follows:

Y_n＝(T_s*ω_c2*X_n)/(1+T_s*ω_c2)+Y_n-1/(1+T_s*ω_c2)

wherein, Y_nIs the same frequency component, X, of the present direct axis current_nIs the AC component in the present direct current, Y_n-1Is the same frequency component, T, of the historical direct axis current_sCalculating a period, ω, for said samples_c2Is the second cut-off angular frequency;

substituting the sampling calculation period, the second cut-off angle frequency, the alternating current component in the current quadrature axis current and the same-frequency component of the historical quadrature axis current into a fifth preset algorithm to calculate the same-frequency component of the current quadrature axis current corresponding to the permanent magnet synchronous motor, wherein the fifth preset algorithm is as follows:

Y_n＝(T_s*ω_c2*X_n)/(1+T_s*ω_c2)+Y_n-1/(1+T_s*ω_c2)

wherein, Y_nFor the co-frequency component, X, of the present quadrature axis current_nBeing an alternating component in said present quadrature-axis current, Y_n-1Is the same frequency component, T, of the historical quadrature axis current_sCalculating a period, ω, for said samples_c2Is the second cut-off angular frequency.

Optionally, the calculating a direct axis voltage instruction and a quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the current calculated value of the direct axis current and the current calculated value of the quadrature axis current includes:

and inputting the current direct-axis current calculated value and the current quadrature-axis current calculated value into a preset proportional-integral regulator to obtain a quadrature-axis voltage instruction and a direct-axis voltage instruction corresponding to the permanent magnet synchronous motor.

Optionally, the converting the current three-phase current value into a current direct axis current calculated value and a current quadrature axis current calculated value includes:

acquiring a current rotor position signal corresponding to the permanent magnet synchronous motor;

converting the current three-phase current value into the current direct-axis current calculated value and the current quadrature-axis current calculated value using the current rotor position signal, a Clark transformation formula, and a park transformation formula.

Optionally, the controlling the permanent magnet synchronous motor according to the target direct axis voltage instruction and the target quadrature axis voltage instruction includes:

substituting the target direct axis voltage command and the target quadrature axis voltage command into an SVPWM (Space vector pulse width Modulation) algorithm to calculate the duty ratio corresponding to the permanent magnet synchronous motor;

converting the current direct-current bus voltage corresponding to the permanent magnet synchronous motor into a target three-phase alternating-current voltage according to the duty ratio;

and controlling the permanent magnet synchronous motor by using the target three-phase alternating current voltage.

In a second aspect, the present invention also provides an apparatus for suppressing imbalance of three-phase currents, the apparatus comprising:

the acquisition unit is used for acquiring the current three-phase current value corresponding to the permanent magnet synchronous motor;

the conversion unit is used for converting the current three-phase current value into a current direct-axis current calculation value and a current quadrature-axis current calculation value;

the first calculation unit is used for calculating a direct axis voltage instruction and a quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the current direct axis current calculation value and the current quadrature axis current calculation value, and calculating a direct axis voltage compensation quantity and a quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to the current direct axis current calculation value and the current quadrature axis current calculation value;

the second calculation unit is used for calculating a target direct axis voltage instruction and a target quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the direct axis voltage instruction, the quadrature axis voltage instruction, the direct axis voltage compensation quantity and the quadrature axis voltage compensation quantity;

and the control unit is used for controlling the permanent magnet synchronous motor according to the target direct axis voltage instruction and the target quadrature axis voltage instruction.

Optionally, the first computing unit includes:

the first processing module is used for carrying out high-pass filtering processing on the current direct-axis current calculated value and the current quadrature-axis current calculated value so as to obtain an alternating current component in the current direct-axis current and an alternating current component in the current quadrature-axis current corresponding to the permanent magnet synchronous motor;

the second processing module is used for performing phase compensation processing on the alternating current component in the current direct-axis current and the alternating current component in the current quadrature-axis current so as to obtain a same-frequency component of the current direct-axis current and a same-frequency component of the current quadrature-axis current corresponding to the permanent magnet synchronous motor;

the first calculation module is used for calculating quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to a first preset proportionality coefficient and the same-frequency component of the current quadrature axis current, and calculating direct axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to a second preset proportionality coefficient and the same-frequency component of the current quadrature axis current.

Optionally, the first processing module includes:

the first acquisition submodule is used for acquiring a sampling calculation period, a first cut-off angle frequency corresponding to the permanent magnet synchronous motor, a historical direct-axis current calculation value, a historical quadrature-axis current calculation value, an alternating current component in historical direct-axis current and an alternating current component in historical quadrature-axis current;

a first calculating submodule, configured to substitute the sampling calculation period, the first cut-off angle frequency, the current direct-axis current calculated value, the historical direct-axis current calculated value, and an alternating component in the historical direct-axis current into a first preset algorithm to calculate an alternating component in the current direct-axis current corresponding to the permanent magnet synchronous motor, where the first preset algorithm is as follows:

Y_n＝(X_n-X_n-1+Y_n-1)/(1+T_s*ω_c1)

wherein, Y_nFor the AC component in the present direct current, X_nCalculating a value, X, for said current direct axis current_n-1Calculating a value for said historical direct axis current, Y_n-1For the intersection in the historical direct-axis currentFlow component, T_sCalculating a period, ω, for said samples_c1Is the first cut-off angle frequency;

a second calculating submodule, configured to substitute an alternating current component in the sampling calculation period, the first cut-off angle frequency, the current quadrature axis current calculation value, the historical quadrature axis current calculation value, and the historical quadrature axis current into a second preset algorithm to calculate an alternating current component in the current quadrature axis current corresponding to the permanent magnet synchronous motor, where the second preset algorithm is as follows:

Y_n＝(X_n-X_n-1+Y_n-1)/(1+T_s*ω_c1)

Optionally, the second processing module includes:

the second acquisition submodule is used for acquiring the pole pair number, the current revolution number, the same-frequency component of historical direct-axis current and the same-frequency component of historical quadrature-axis current corresponding to the permanent magnet synchronous motor;

a third calculating submodule, configured to substitute the first cut-off angular frequency, the pole pair number, and the current rotation number into a third preset algorithm to calculate a second cut-off angular frequency corresponding to the permanent magnet synchronous motor, where the third preset algorithm is as follows:

ω_c2＝ω_e ²/ω_c1ω_e＝(2π*P*n)/60

a fourth calculation submodule, configured to substitute the sampling calculation period, the second cut-off angular frequency, the alternating current component in the current direct-axis current, and the same-frequency component of the historical direct-axis current into a fourth preset algorithm, so as to calculate the same-frequency component of the current direct-axis current corresponding to the permanent magnet synchronous motor, where the fourth preset algorithm is as follows:

Y_n＝(T_s*ω_c2*X_n)/(1+T_s*ω_c2)+Y_n-1/(1+T_s*ω_c2)

a fifth calculating submodule, configured to substitute the sampling calculation period, the second cut-off angle frequency, the alternating current component in the current quadrature axis current, and the same-frequency component of the historical quadrature axis current into a fifth preset algorithm, so as to calculate the same-frequency component of the current quadrature axis current corresponding to the permanent magnet synchronous motor, where the fifth preset algorithm is as follows:

Y_n＝(T_s*ω_c2*X_n)/(1+T_s*ω_c2)+Y_n-1/(1+T_s*ω_c2)

Optionally, the first computing unit includes:

and the input module is used for inputting the current direct-axis current calculated value and the current quadrature-axis current calculated value into a preset proportional-integral regulator so as to obtain a quadrature-axis voltage instruction and a direct-axis voltage instruction corresponding to the permanent magnet synchronous motor.

Optionally, the conversion unit includes:

the acquisition module is used for acquiring a current rotor position signal corresponding to the permanent magnet synchronous motor;

a first conversion module for converting the current three-phase current value into the current direct-axis current calculation value and the current quadrature-axis current calculation value using the current rotor position signal, a clark transformation formula, and a park transformation formula.

Optionally, the control unit includes:

the second calculation module is used for substituting the target direct axis voltage command and the target quadrature axis voltage command into an SVPWM (Space Vector Pulse Width Modulation) algorithm to calculate a duty ratio corresponding to the permanent magnet synchronous motor;

the second conversion module is used for converting the current direct-current bus voltage corresponding to the permanent magnet synchronous motor into a target three-phase alternating-current voltage according to the duty ratio;

and the control module is used for controlling the permanent magnet synchronous motor by using the target three-phase alternating current voltage.

In a third aspect, an embodiment of the present invention provides a storage medium, where the storage medium includes a stored program, and when the program runs, the apparatus on which the storage medium is controlled to execute the method for suppressing three-phase current imbalance according to the first aspect.

In a fourth aspect, embodiments of the present invention provide an apparatus for suppressing three-phase current imbalance, the apparatus including a storage medium; and one or more processors, the storage medium coupled with the processors, the processors configured to execute program instructions stored in the storage medium; the program instructions when executed perform the method of suppressing three-phase current imbalance of the first aspect.

By the technical scheme, the technical scheme provided by the invention at least has the following advantages:

the invention provides a method and a device for inhibiting three-phase current unbalance, which can convert a current three-phase current value corresponding to a permanent magnet synchronous motor into a current direct axis current calculated value and a current quadrature axis current calculated value by a motor controller after the current three-phase current value is obtained by the motor controller through a current sensor, calculate a direct axis voltage instruction and a quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the current direct axis current calculated value and the current quadrature axis current calculated value, calculate a direct axis voltage compensation quantity and a quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to the current direct axis current calculated value and the current quadrature axis current calculated value, and calculate a target direct axis voltage instruction and a target quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the direct axis voltage instruction, the quadrature axis voltage instruction, the direct axis voltage compensation quantity and the quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor, and finally, controlling the current output of the permanent magnet synchronous motor according to a target direct axis voltage instruction and a target quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor. The motor controller calculates the direct-axis voltage compensation quantity and the quadrature-axis voltage compensation quantity according to the current direct-axis current calculation value and the current quadrature-axis current calculation value corresponding to the permanent magnet synchronous motor, then compensates the direct-axis voltage command by using the direct-axis voltage compensation quantity to obtain the target direct-axis voltage command, compensates the quadrature-axis voltage command by using the quadrature-axis voltage compensation quantity to obtain the target quadrature-axis voltage command, and finally controls the current output of the permanent magnet synchronous motor according to the target direct-axis voltage command and the target quadrature-axis voltage command.

The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

fig. 1 is a schematic diagram illustrating a three-phase current imbalance of a permanent magnet synchronous motor according to an embodiment of the present invention;

FIG. 2 is a flow chart illustrating a method for suppressing three-phase current imbalance according to an embodiment of the present invention;

FIG. 3 is a flow chart illustrating another method for suppressing three-phase current imbalance according to an embodiment of the present invention;

fig. 4 is a block diagram illustrating a device for suppressing imbalance of three-phase currents according to an embodiment of the present invention;

fig. 5 is a block diagram illustrating another apparatus for suppressing three-phase current imbalance according to an embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

An embodiment of the present invention provides a method for suppressing imbalance of three-phase currents, as shown in fig. 2, where the method includes:

101. and acquiring a current three-phase current value corresponding to the permanent magnet synchronous motor, and converting the current three-phase current value into a current direct axis current calculated value and a current quadrature axis current calculated value.

In the embodiment of the present invention, the main execution body in each step is a Motor Controller (MCU) in an electric vehicle. In order to suppress the occurrence of the phenomenon of unbalanced three-phase current of the permanent magnet synchronous motor due to the temperature drift phenomenon of the current sensor and the production and assembly precision of the rotary transformer, the motor controller firstly needs to obtain a current three-phase current value corresponding to the permanent magnet synchronous motor through the current sensor, convert the current three-phase current value into a current direct axis current calculated value and a current quadrature axis current calculated value, so as to calculate a target direct axis voltage instruction (i.e. a compensated direct axis voltage instruction) and a target quadrature axis voltage instruction (i.e. a compensated quadrature axis voltage instruction) corresponding to the permanent magnet synchronous motor based on the current direct axis current calculated value and the current quadrature axis current calculated value corresponding to the permanent magnet synchronous motor, and control the current output of the permanent magnet synchronous motor according to the target direct axis voltage instruction and the target quadrature axis voltage instruction obtained through calculation.

Specifically, in this step, the motor controller may convert the current three-phase current value corresponding to the permanent magnet synchronous motor into the current direct-axis current calculated value and the current quadrature-axis current calculated value by the following method: firstly, acquiring a current rotor position signal corresponding to the permanent magnet synchronous motor through a rotary transformer; then, the current three-phase current value is converted into a current direct-axis current calculation value and a current quadrature-axis current calculation value by using the current rotor position signal, the clark transformation formula and the park transformation formula, that is, the current rotor position signal and the current three-phase current value are substituted into the clark transformation formula to obtain an intermediate calculation result by calculation, and the intermediate calculation result is substituted into the park transformation formula to obtain the current direct-axis current calculation value and the current quadrature-axis current calculation value by calculation, but not limited thereto.

102. And calculating a direct axis voltage instruction and a quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the current direct axis current calculated value and the current quadrature axis current calculated value, and calculating a direct axis voltage compensation amount and a quadrature axis voltage compensation amount corresponding to the permanent magnet synchronous motor according to the current direct axis current calculated value and the current quadrature axis current calculated value.

In the embodiment of the invention, after converting the current three-phase current value corresponding to the permanent magnet synchronous motor into the current direct axis current calculated value and the current quadrature axis current calculated value, the motor controller can calculate the direct axis voltage command and the quadrature axis voltage command corresponding to the permanent magnet synchronous motor according to the current direct axis current calculated value and the current quadrature axis current calculated value corresponding to the permanent magnet synchronous motor, and calculate the direct axis voltage compensation quantity and the quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to the current direct axis current calculated value and the current quadrature axis current calculated value corresponding to the permanent magnet synchronous motor, so as to compensate the direct axis voltage command by using the direct axis voltage compensation quantity corresponding to the permanent magnet synchronous motor subsequently, thereby obtaining the target direct axis voltage command corresponding to the permanent magnet synchronous motor, and compensate the quadrature axis voltage command by using the quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor, and therefore, a target quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor is obtained.

Specifically, in this step, the motor controller may calculate the direct axis voltage command and the quadrature axis voltage command corresponding to the permanent magnet synchronous motor according to the current direct axis current calculated value and the current quadrature axis current calculated value corresponding to the permanent magnet synchronous motor by using the following method: the current direct-axis current calculated value and the current quadrature-axis current calculated value corresponding to the permanent magnet synchronous motor are input into a preset proportional-integral regulator, the preset proportional-integral regulator calculates a direct-axis voltage instruction and a quadrature-axis voltage instruction corresponding to the permanent magnet synchronous motor according to the received current direct-axis current calculated value and the received current quadrature-axis current calculated value, and outputs the calculated direct-axis voltage instruction and quadrature-axis voltage instruction, at the moment, the motor controller can obtain the direct-axis voltage instruction and the quadrature-axis voltage instruction corresponding to the permanent magnet synchronous motor, but the method is not limited to this.

103. And calculating a target direct axis voltage instruction and a target quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the direct axis voltage instruction, the quadrature axis voltage instruction, the direct axis voltage compensation quantity and the quadrature axis voltage compensation quantity.

In the embodiment of the invention, after the motor controller calculates and obtains the direct axis voltage command, the quadrature axis voltage command, the direct axis voltage compensation quantity and the quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to the current direct axis current calculated value and the current quadrature axis current calculated value corresponding to the permanent magnet synchronous motor, the target direct axis voltage command and the target quadrature axis voltage command corresponding to the permanent magnet synchronous motor can be calculated according to the direct axis voltage command, the quadrature axis voltage command, the direct axis voltage compensation quantity and the quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor, namely, the direct axis voltage instruction and the direct axis voltage compensation quantity corresponding to the permanent magnet synchronous motor are summed and calculated, so as to obtain a target direct axis voltage instruction corresponding to the permanent magnet synchronous motor, and summing the quadrature axis voltage command and the quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor to obtain a target quadrature axis voltage command corresponding to the permanent magnet synchronous motor.

104. And controlling the permanent magnet synchronous motor according to the target direct axis voltage instruction and the target quadrature axis voltage instruction.

In the embodiment of the invention, after the motor controller calculates and obtains the target direct axis voltage command and the target quadrature axis voltage command corresponding to the permanent magnet synchronous motor according to the direct axis voltage command, the quadrature axis voltage command, the direct axis voltage compensation quantity and the quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor, the current output of the permanent magnet synchronous motor can be controlled according to the target direct axis voltage command and the target quadrature axis voltage command corresponding to the permanent magnet synchronous motor. Because the motor controller calculates the direct axis voltage command, the quadrature axis voltage command, the direct axis voltage compensation quantity and the quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to the current direct axis current calculation value and the current quadrature axis current calculation value corresponding to the permanent magnet synchronous motor; compensating the direct axis voltage command by using the direct axis voltage compensation quantity corresponding to the permanent magnet synchronous motor to obtain a target direct axis voltage command corresponding to the permanent magnet synchronous motor, and compensating the quadrature axis voltage command by using the quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor to obtain a target quadrature axis voltage command corresponding to the permanent magnet synchronous motor; and finally, controlling the current output of the permanent magnet synchronous motor according to the target direct axis voltage instruction and the target quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor, so that the phenomenon of unbalanced three-phase current of the permanent magnet synchronous motor caused by the temperature drift phenomenon of a current sensor and the production and assembly precision of a rotary transformer can be effectively inhibited.

The embodiment of the invention provides a method for inhibiting three-phase current unbalance, which can convert a current three-phase current value into a current direct-axis current calculated value and a current quadrature-axis current calculated value by a motor controller after the current three-phase current value corresponding to a permanent magnet synchronous motor is obtained by the motor controller through a current sensor, calculate a direct-axis voltage command and a quadrature-axis voltage command corresponding to the permanent magnet synchronous motor according to the current direct-axis current calculated value and the current quadrature-axis current calculated value, calculate a direct-axis voltage compensation quantity and a quadrature-axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to the current direct-axis current calculated value and the current quadrature-axis current calculated value, and calculate a target direct-axis voltage command and a target quadrature-axis voltage command corresponding to the permanent magnet synchronous motor according to the direct-axis voltage command, the quadrature-axis voltage command, the direct-axis voltage compensation quantity and the quadrature-axis voltage compensation quantity corresponding to the permanent magnet synchronous motor, and finally, controlling the current output of the permanent magnet synchronous motor according to a target direct axis voltage instruction and a target quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor. The motor controller calculates the direct-axis voltage compensation quantity and the quadrature-axis voltage compensation quantity according to the current direct-axis current calculation value and the current quadrature-axis current calculation value corresponding to the permanent magnet synchronous motor, then compensates the direct-axis voltage command by using the direct-axis voltage compensation quantity to obtain the target direct-axis voltage command, compensates the quadrature-axis voltage command by using the quadrature-axis voltage compensation quantity to obtain the target quadrature-axis voltage command, and finally controls the current output of the permanent magnet synchronous motor according to the target direct-axis voltage command and the target quadrature-axis voltage command.

For purposes of more detailed description, another method for suppressing three-phase current imbalance is provided in the embodiments of the present invention, and as shown in fig. 3 in particular, the method includes:

201. and acquiring a current three-phase current value corresponding to the permanent magnet synchronous motor, and converting the current three-phase current value into a current direct axis current calculated value and a current quadrature axis current calculated value.

In step 201, the current three-phase current value corresponding to the permanent magnet synchronous motor is obtained, and the current three-phase current value is converted into the current direct axis current calculated value and the current quadrature axis current calculated value, which may refer to the description of the corresponding part in fig. 2, and the embodiment of the present invention will not be described again here.

202. And calculating a direct axis voltage instruction and a quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the current direct axis current calculated value and the current quadrature axis current calculated value.

In step 202, a direct-axis voltage command and a quadrature-axis voltage command corresponding to the permanent magnet synchronous motor are calculated according to the current calculated value of the direct-axis current and the current calculated value of the quadrature-axis current, which may refer to the description of the corresponding parts in fig. 2, and will not be described again in this embodiment of the present invention.

203. And calculating the direct axis voltage compensation quantity and the quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to the current direct axis current calculation value and the current quadrature axis current calculation value.

In the embodiment of the invention, after converting the current three-phase current value corresponding to the permanent magnet synchronous motor into the current direct axis current calculated value and the current quadrature axis current calculated value, the motor controller can calculate the direct axis voltage compensation quantity and the quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to the current direct axis current calculated value and the current quadrature axis current calculated value corresponding to the permanent magnet synchronous motor. The following will describe in detail how the motor controller calculates the dc-axis voltage compensation amount and the quadrature-axis voltage compensation amount corresponding to the permanent magnet synchronous motor according to the current calculated value of the dc current and the current calculated value of the quadrature-axis current corresponding to the permanent magnet synchronous motor.

(1) And carrying out high-pass filtering processing on the current direct-axis current calculated value and the current quadrature-axis current calculated value to obtain an alternating current component in the current direct-axis current and an alternating current component in the current quadrature-axis current corresponding to the permanent magnet synchronous motor.

In the embodiment of the invention, after converting the current three-phase current value corresponding to the permanent magnet synchronous motor into the current direct axis current calculated value and the current quadrature axis current calculated value, the motor controller can perform high-pass filtering processing on the current direct axis current calculated value and the current quadrature axis current calculated value corresponding to the permanent magnet synchronous motor, so as to obtain the alternating current component in the current direct axis current and the alternating current component in the current quadrature axis current corresponding to the permanent magnet synchronous motor.

Specifically, in this step, the motor controller may perform high-pass filtering processing on the current direct-axis current calculated value and the current quadrature-axis current calculated value corresponding to the permanent magnet synchronous motor in the following manner, so as to obtain an alternating current component in the current direct-axis current and an alternating current component in the current quadrature-axis current corresponding to the permanent magnet synchronous motor:

firstly, acquiring a sampling calculation period, a first cut-off angle frequency corresponding to the permanent magnet synchronous motor, a historical direct axis current calculation value, a historical quadrature axis current calculation value, an alternating current component in the historical direct axis current and an alternating current component in the historical quadrature axis current.

The sampling calculation period is a time preset by a worker and lasting in each sampling calculation process, and the sampling calculation period may be, but is not limited to: 0.5s, 1s, 3s, 5s, etc.; the first cut-off angle frequency corresponding to the permanent magnet synchronous motor is preset by a worker. The current direct-axis current calculation value and the current quadrature-axis current calculation value corresponding to the permanent magnet synchronous motor are obtained by the motor controller in the sampling calculation process; the historical direct-axis current calculation value and the historical quadrature-axis current calculation value corresponding to the permanent magnet synchronous motor are obtained by the motor controller in the last sampling calculation process; and the alternating current component in the historical direct-axis current and the alternating current component in the historical quadrature-axis current corresponding to the permanent magnet synchronous motor are obtained by the motor controller in the last sampling calculation process.

Then, substituting the sampling calculation period, the first cut-off angle frequency corresponding to the permanent magnet synchronous motor, the current direct axis current calculation value, the historical direct axis current calculation value and the alternating current component in the historical direct axis current into a first preset algorithm, so as to calculate the alternating current component in the current direct axis current corresponding to the permanent magnet synchronous motor, wherein the first preset algorithm specifically comprises the following steps:

Y_n＝(X_n-X_n-1+Y_n-1)/(1+T_s*ω_c1)

wherein, Y_nIs the AC component, X, in the current direct-axis current corresponding to the permanent magnet synchronous motor_nThe current direct axis current calculated value, X, corresponding to the permanent magnet synchronous motor_n-1Calculating a value, Y, for a historical direct-axis current corresponding to a PMSM_n-1Alternating current component in historical direct-axis current corresponding to permanent magnet synchronous motor，T_sCalculating the period, ω, for the samples_c1The first cut-off angle frequency is corresponding to the permanent magnet synchronous motor.

And finally, substituting the sampling calculation period, the first cut-off angle frequency corresponding to the permanent magnet synchronous motor, the current quadrature axis current calculation value, the historical quadrature axis current calculation value and the alternating current component in the historical quadrature axis current into a second preset algorithm so as to calculate the alternating current component in the current quadrature axis current corresponding to the permanent magnet synchronous motor, wherein the second preset algorithm is as follows:

Y_n＝(X_n-X_n-1+Y_n-1)/(1+T_s*ω_c1)

wherein, Y_nIs the AC component, X, in the present quadrature-axis current corresponding to the PMSM_nThe current quadrature axis current calculated value, X, corresponding to the permanent magnet synchronous motor_n-1Calculating a value, Y, for a historical quadrature axis current corresponding to a PMSM_n-1Is an alternating current component, T, in the historical quadrature axis current corresponding to the permanent magnet synchronous motor_sCalculating the period, ω, for the samples_c1The first cut-off angle frequency is corresponding to the permanent magnet synchronous motor.

(2) And carrying out phase compensation processing on the alternating current component in the current direct-axis current and the alternating current component in the current quadrature-axis current so as to obtain the same-frequency component of the current direct-axis current and the same-frequency component of the current quadrature-axis current corresponding to the permanent magnet synchronous motor.

In the embodiment of the invention, after the motor controller performs high-pass filtering processing on the current direct-axis current calculated value and the current quadrature-axis current calculated value corresponding to the permanent magnet synchronous motor so as to obtain the alternating current component in the current direct-axis current and the alternating current component in the current quadrature-axis current corresponding to the permanent magnet synchronous motor, the motor controller can perform phase compensation processing on the alternating current component in the current direct-axis current and the alternating current component in the current quadrature-axis current corresponding to the permanent magnet synchronous motor so as to obtain the same-frequency component of the current direct-axis current and the same-frequency component of the current quadrature-axis current corresponding to the permanent magnet synchronous motor.

Specifically, in this step, the motor controller may perform phase compensation processing on the ac component in the current direct-axis current and the ac component in the current quadrature-axis current corresponding to the permanent magnet synchronous motor in the following manner, so as to obtain the same-frequency component of the current direct-axis current and the same-frequency component of the current quadrature-axis current corresponding to the permanent magnet synchronous motor:

firstly, acquiring the pole pair number, the current revolution number, the same-frequency component of historical direct-axis current and the same-frequency component of historical quadrature-axis current corresponding to the permanent magnet synchronous motor. The number of pole pairs corresponding to the permanent magnet synchronous motor is a parameter of the permanent magnet synchronous motor. The same-frequency components of the historical direct-axis current and the historical quadrature-axis current corresponding to the permanent magnet synchronous motor are obtained by the motor controller in the last sampling calculation process.

Then, substituting the first cut-off angle frequency, the pole pair number and the current revolution number corresponding to the permanent magnet synchronous motor into a third preset algorithm, so as to calculate a second cut-off angle frequency corresponding to the permanent magnet synchronous motor, wherein the third preset algorithm specifically comprises the following steps:

ω_c2＝ω_e ²/ω_c1ω_e＝(2π*P*n)/60

wherein, ω is_c2Second cut-off angular frequency, omega, for a permanent magnet synchronous machine_c1The first cutoff angular frequency is corresponding to the permanent magnet synchronous motor, P is the number of pole pairs corresponding to the permanent magnet synchronous motor, and n is the current revolution corresponding to the permanent magnet synchronous motor.

Secondly, substituting the sampling calculation period, a second cut-off angular frequency corresponding to the permanent magnet synchronous motor, an alternating current component in the current direct-axis current and a same-frequency component of the historical direct-axis current into a fourth preset algorithm, and calculating the same-frequency component of the current direct-axis current corresponding to the permanent magnet synchronous motor, wherein the fourth preset algorithm is as follows:

Y_n＝(T_s*ω_c2*X_n)/(1+T_s*ω_c2)+Y_n-1/(1+T_s*ω_c2)

wherein, Y_nIs the same frequency component, X, of the current direct axis current corresponding to the permanent magnet synchronous motor_nFor permanent magnet synchronous motorOf the present direct axis current, Y_n-1Is the same frequency component, T, of the historical direct axis current corresponding to the permanent magnet synchronous motor_sCalculating the period, ω, for the samples_c2And the second cut-off angular frequency corresponds to the permanent magnet synchronous motor.

And finally, substituting the sampling calculation period, the second cut-off angular frequency corresponding to the permanent magnet synchronous motor, the alternating current component in the current quadrature axis current and the same-frequency component of the historical quadrature axis current into a fifth preset algorithm, so as to calculate the same-frequency component of the current quadrature axis current corresponding to the permanent magnet synchronous motor, wherein the fifth preset algorithm is specifically as follows:

Y_n＝(T_s*ω_c2*X_n)/(1+T_s*ω_c2)+Y_n-1/(1+T_s*ω_c2)

wherein, Y_nIs the same frequency component, X, of the current quadrature axis current corresponding to the permanent magnet synchronous motor_nIs the AC component, Y, in the present quadrature-axis current corresponding to the PMSM_n-1Is the same frequency component, T, of the historical quadrature axis current corresponding to the permanent magnet synchronous motor_sCalculating the period, ω, for the samples_c2And the second cut-off angular frequency corresponds to the permanent magnet synchronous motor.

(3) And calculating quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to the first preset proportionality coefficient and the same-frequency component of the current direct axis current, and calculating direct axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to the second preset proportionality coefficient and the same-frequency component of the current quadrature axis current.

In the embodiment of the present invention, the magnitude of the first preset proportionality coefficient and the magnitude of the second preset proportionality coefficient are not specifically limited.

In the embodiment of the invention, after the motor controller performs phase compensation processing on an alternating current component in the current direct-axis current and an alternating current component in the current quadrature-axis current corresponding to the permanent magnet synchronous motor so as to obtain a same-frequency component of the current direct-axis current and a same-frequency component of the current quadrature-axis current corresponding to the permanent magnet synchronous motor, a quadrature-axis voltage compensation quantity corresponding to the permanent magnet synchronous motor can be calculated according to a first preset proportionality coefficient and the same-frequency component of the current direct-axis current corresponding to the permanent magnet synchronous motor, namely, the first preset proportionality coefficient and the same-frequency component of the current direct-axis current corresponding to the permanent magnet synchronous motor are subjected to quadrature calculation so as to obtain a quadrature-axis voltage compensation quantity corresponding to the permanent magnet synchronous motor; and calculating the direct-axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to the second preset proportionality coefficient and the same-frequency component of the current quadrature-axis current corresponding to the permanent magnet synchronous motor, namely performing product calculation on the second preset proportionality coefficient and the same-frequency component of the current quadrature-axis current corresponding to the permanent magnet synchronous motor, so as to obtain the direct-axis voltage compensation quantity corresponding to the permanent magnet synchronous motor.

204. And calculating a target direct axis voltage instruction and a target quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the direct axis voltage instruction, the quadrature axis voltage instruction, the direct axis voltage compensation quantity and the quadrature axis voltage compensation quantity.

In step 204, a target direct-axis voltage command and a target quadrature-axis voltage command corresponding to the permanent magnet synchronous motor are calculated according to the direct-axis voltage command, the quadrature-axis voltage command, the direct-axis voltage compensation amount, and the quadrature-axis voltage compensation amount, which may refer to the description of the corresponding part in fig. 2, and will not be described herein again in the embodiments of the present invention.

205. And controlling the permanent magnet synchronous motor according to the target direct axis voltage instruction and the target quadrature axis voltage instruction.

In step 205, the permanent magnet synchronous motor is controlled according to the target direct-axis voltage command and the target quadrature-axis voltage command, which may refer to the description of the corresponding part in fig. 2, and will not be described again in this embodiment of the present invention.

Further, in the embodiment of the present invention, the motor controller may control the permanent magnet synchronous motor according to the target direct axis voltage command and the target quadrature axis voltage command corresponding to the permanent magnet synchronous motor by using the following method: firstly, substituting a target direct axis voltage instruction and a target quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor into an SVPWM (Space Vector Pulse width modulation) algorithm, so as to calculate the duty ratio corresponding to the permanent magnet synchronous motor; then, chopping current direct-current bus voltage corresponding to the permanent magnet synchronous motor according to the duty ratio corresponding to the permanent magnet synchronous motor, so that the current direct-current bus voltage corresponding to the permanent magnet synchronous motor is converted into target three-phase alternating-current voltage; and finally, controlling the current output of the permanent magnet synchronous motor by using the target three-phase alternating current voltage corresponding to the permanent magnet synchronous motor.

Further, as an implementation of the method shown in fig. 2 and 3, another embodiment of the present invention further provides an apparatus for suppressing imbalance of three-phase currents. The embodiment of the apparatus corresponds to the embodiment of the method, and for convenience of reading, details in the embodiment of the apparatus are not repeated one by one, but it should be clear that the apparatus in the embodiment can correspondingly implement all the contents in the embodiment of the method. The device is applied to restraining the phenomenon of unbalanced three-phase current of the permanent magnet synchronous motor caused by the temperature drift phenomenon of a current sensor and the production and assembly precision of a rotary transformer, and particularly as shown in figure 4, the device comprises:

the acquiring unit 31 is configured to acquire a current three-phase current value corresponding to the permanent magnet synchronous motor;

a conversion unit 32 for converting the current three-phase current value into a current direct-axis current calculation value and a current quadrature-axis current calculation value;

a first calculating unit 33, configured to calculate a direct axis voltage instruction and a quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the current calculated direct axis current value and the current calculated quadrature axis current value, and calculate a direct axis voltage compensation amount and a quadrature axis voltage compensation amount corresponding to the permanent magnet synchronous motor according to the current calculated direct axis current value and the current calculated quadrature axis current value;

a second calculating unit 34, configured to calculate a target direct axis voltage instruction and a target quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the direct axis voltage instruction, the quadrature axis voltage instruction, the direct axis voltage compensation amount, and the quadrature axis voltage compensation amount;

and the control unit 35 is configured to control the permanent magnet synchronous motor according to the target direct axis voltage instruction and the target quadrature axis voltage instruction.

Further, as shown in fig. 5, the first calculation unit 33 includes:

the first processing module 331 is configured to perform high-pass filtering processing on the current direct-axis current calculated value and the current quadrature-axis current calculated value to obtain an alternating current component in the current direct-axis current and an alternating current component in the current quadrature-axis current corresponding to the permanent magnet synchronous motor;

a second processing module 332, configured to perform phase compensation processing on the alternating current component in the current direct-axis current and the alternating current component in the current quadrature-axis current, so as to obtain a same-frequency component of the current direct-axis current and a same-frequency component of the current quadrature-axis current, which correspond to the permanent magnet synchronous motor;

the first calculating module 333 is configured to calculate a quadrature axis voltage compensation amount corresponding to the permanent magnet synchronous motor according to a first preset proportionality coefficient and a same-frequency component of the current quadrature axis current, and calculate a direct axis voltage compensation amount corresponding to the permanent magnet synchronous motor according to a second preset proportionality coefficient and a same-frequency component of the current quadrature axis current.

Further, as shown in fig. 5, the first processing module 331 includes:

the first obtaining submodule 3311 is configured to obtain a sampling calculation period, a first cut-off angle frequency corresponding to the permanent magnet synchronous motor, a historical direct-axis current calculation value, a historical quadrature-axis current calculation value, an alternating current component in the historical direct-axis current, and an alternating current component in the historical quadrature-axis current;

a first calculating submodule 3312, configured to substitute alternating current components in the sampling calculation period, the first cut-off angle frequency, the current direct-axis current calculation value, the historical direct-axis current calculation value, and the historical direct-axis current into a first preset algorithm to calculate an alternating current component in the current direct-axis current corresponding to the permanent magnet synchronous motor, where the first preset algorithm is as follows:

Y_n＝(X_n-X_n-1+Y_n-1)/(1+T_s*ω_c1)

a second calculating submodule 3313, configured to substitute alternating current components in the sampling calculation period, the first cut-off angle frequency, the current quadrature axis current calculation value, the historical quadrature axis current calculation value, and the historical quadrature axis current into a second preset algorithm to calculate an alternating current component in the current quadrature axis current corresponding to the permanent magnet synchronous motor, where the second preset algorithm is as follows:

Y_n＝(X_n-X_n-1+Y_n-1)/(1+T_s*ω_c1)

Further, as shown in fig. 5, the second processing module 332 includes:

the second obtaining submodule 3321 is configured to obtain the number of pole pairs, the current revolution, the same-frequency component of the historical direct-axis current, and the same-frequency component of the historical quadrature-axis current corresponding to the permanent magnet synchronous motor;

a third calculating submodule 3322, configured to substitute the first cut-off angular frequency, the pole pair number, and the current rotation number into a third preset algorithm to calculate a second cut-off angular frequency corresponding to the permanent magnet synchronous motor, where the third preset algorithm is as follows:

ω_c2＝ω_e ²/ω_c1ω_e＝(2π*P*n)/60

a fourth calculating submodule 3323, configured to substitute the sampling calculation period, the second cut-off angle frequency, the alternating current component in the current direct-axis current, and the same-frequency component of the historical direct-axis current into a fourth preset algorithm, so as to calculate the same-frequency component of the current direct-axis current corresponding to the permanent magnet synchronous motor, where the fourth preset algorithm is as follows:

Y_n＝(T_s*ω_c2*X_n)/(1+T_s*ω_c2)+Y_n-1/(1+T_s*ω_c2)

a fifth calculating submodule 3324, configured to substitute the sampling calculation period, the second cut-off angle frequency, the alternating current component in the current quadrature axis current, and the same-frequency component of the historical quadrature axis current into a fifth preset algorithm, so as to calculate the same-frequency component of the current quadrature axis current corresponding to the permanent magnet synchronous motor, where the fifth preset algorithm is as follows:

Y_n＝(T_s*ω_c2*X_n)/(1+T_s*ω_c2)+Y_n-1/(1+T_s*ω_c2)

Further, as shown in fig. 5, the first calculation unit 33 includes:

an input module 334, configured to input the current calculated value of the direct axis current and the current calculated value of the quadrature axis current into a preset proportional-integral regulator, so as to obtain a quadrature axis voltage instruction and a direct axis voltage instruction corresponding to the permanent magnet synchronous motor.

Further, as shown in fig. 5, the conversion unit 32 includes:

an obtaining module 321, configured to obtain a current rotor position signal corresponding to the permanent magnet synchronous motor;

a first conversion module 322, configured to convert the current three-phase current value into the current direct-axis current calculated value and the current quadrature-axis current calculated value using the current rotor position signal, the clark transformation formula, and the park transformation formula.

Further, as shown in fig. 5, the control unit 35 includes:

the second calculating module 351 is configured to substitute the target direct-axis voltage command and the target quadrature-axis voltage command into an SVPWM (Space Vector Pulse Width Modulation) algorithm to calculate a duty ratio corresponding to the permanent magnet synchronous motor;

a second conversion module 352, configured to convert a current dc bus voltage corresponding to the permanent magnet synchronous motor into a target three-phase ac voltage according to the duty ratio;

and the control module 353 is used for controlling the permanent magnet synchronous motor by using the target three-phase alternating current voltage.

The embodiment of the invention provides a method and a device for inhibiting three-phase current unbalance, which can convert a current three-phase current value corresponding to a permanent magnet synchronous motor into a current direct axis current calculated value and a current quadrature axis current calculated value by a motor controller after the current three-phase current value is obtained by the motor controller through a current sensor, calculate a direct axis voltage instruction and a quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the current direct axis current calculated value and the current quadrature axis current calculated value, calculate a direct axis voltage compensation quantity and a quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to the current direct axis current calculated value and the current quadrature axis current calculated value, and calculate a target direct axis voltage instruction and a target quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the direct axis voltage instruction, the quadrature axis voltage instruction, the direct axis voltage compensation quantity and the quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor, and finally, controlling the current output of the permanent magnet synchronous motor according to a target direct axis voltage instruction and a target quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor. The motor controller calculates the direct-axis voltage compensation quantity and the quadrature-axis voltage compensation quantity according to the current direct-axis current calculation value and the current quadrature-axis current calculation value corresponding to the permanent magnet synchronous motor, then compensates the direct-axis voltage command by using the direct-axis voltage compensation quantity to obtain the target direct-axis voltage command, compensates the quadrature-axis voltage command by using the quadrature-axis voltage compensation quantity to obtain the target quadrature-axis voltage command, and finally controls the current output of the permanent magnet synchronous motor according to the target direct-axis voltage command and the target quadrature-axis voltage command.

The device for restraining the unbalance of the three-phase currents comprises a processor and a memory, wherein the acquiring unit, the converting unit, the first calculating unit, the second calculating unit, the control unit and the like are stored in the memory as program units, and the processor executes the program units stored in the memory to realize corresponding functions.

The processor comprises a kernel, and the kernel calls the corresponding program unit from the memory. One or more than one inner core can be arranged, and the phenomenon of unbalanced three-phase current of the permanent magnet synchronous motor caused by the temperature drift phenomenon of the current sensor and the production and assembly precision of the rotary transformer is inhibited by adjusting the parameters of the inner cores.

The embodiment of the invention provides a storage medium, which comprises a stored program, wherein when the program runs, a device where the storage medium is located is controlled to execute the method for restraining the unbalance of the three-phase current.

The storage medium may include volatile memory in a computer readable medium, Random Access Memory (RAM) and/or nonvolatile memory such as Read Only Memory (ROM) or flash memory (flash RAM), and the memory includes at least one memory chip.

The embodiment of the invention also provides a device for inhibiting the unbalance of three-phase current, which comprises a storage medium; and one or more processors, the storage medium coupled with the processors, the processors configured to execute program instructions stored in the storage medium; the program instructions when running execute the above method for suppressing three-phase current imbalance.

The embodiment of the invention provides equipment, which comprises a processor, a memory and a program which is stored on the memory and can run on the processor, wherein the processor executes the program and realizes the following steps:

Further, the calculating a direct axis voltage compensation amount and a quadrature axis voltage compensation amount corresponding to the permanent magnet synchronous motor according to the current direct axis current calculation value and the current quadrature axis current calculation value includes:

Further, the performing high-pass filtering processing on the current direct-axis current calculated value and the current quadrature-axis current calculated value to obtain an alternating current component in the current direct-axis current and an alternating current component in the current quadrature-axis current corresponding to the permanent magnet synchronous motor includes:

Y_n＝(X_n-X_n-1+Y_n-1)/(1+T_s*ω_c1)

Further, the performing phase compensation processing on the alternating current component in the current direct-axis current and the alternating current component in the current quadrature-axis current to obtain a same-frequency component of the current direct-axis current and a same-frequency component of the current quadrature-axis current corresponding to the permanent magnet synchronous motor includes:

ω_c2＝ω_e ²/ω_c1ω_e＝(2π*P*n)/60

Y_n＝(T_s*ω_c2*X_n)/(1+T_s*ω_c2)+Y_n-1/(1+T_s*ω_c2)

Further, the calculating a direct axis voltage instruction and a quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the current direct axis current calculation value and the current quadrature axis current calculation value includes:

Further, the converting the current three-phase current value into a current direct-axis current calculated value and a current quadrature-axis current calculated value includes:

Further, the controlling the permanent magnet synchronous motor according to the target direct axis voltage command and the target quadrature axis voltage command includes:

The present application further provides a computer program product adapted to perform program code for initializing the following method steps when executed on a data processing device: acquiring a current three-phase current value corresponding to the permanent magnet synchronous motor, and converting the current three-phase current value into a current direct axis current calculated value and a current quadrature axis current calculated value; calculating a direct axis voltage instruction and a quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the current direct axis current calculated value and the current quadrature axis current calculated value, and calculating a direct axis voltage compensation quantity and a quadrature axis voltage compensation quantity corresponding to the permanent magnet synchronous motor according to the current direct axis current calculated value and the current quadrature axis current calculated value; calculating a target direct axis voltage instruction and a target quadrature axis voltage instruction corresponding to the permanent magnet synchronous motor according to the direct axis voltage instruction, the quadrature axis voltage instruction, the direct axis voltage compensation quantity and the quadrature axis voltage compensation quantity; and controlling the permanent magnet synchronous motor according to the target direct axis voltage instruction and the target quadrature axis voltage instruction.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In a typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include forms of volatile memory in a computer readable medium, Random Access Memory (RAM) and/or non-volatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). The memory is an example of a computer-readable medium.

Computer-readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer readable medium does not include a transitory computer readable medium such as a modulated data signal and a carrier wave.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in the process, method, article, or apparatus that comprises the element.

The above are merely examples of the present application and are not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A method of suppressing a three-phase current imbalance, comprising:

2. The method of claim 1, wherein the calculating the compensation amount of the direct-axis voltage and the compensation amount of the quadrature-axis voltage corresponding to the permanent magnet synchronous motor according to the calculated value of the current direct-axis current and the calculated value of the current quadrature-axis current comprises:

3. The method according to claim 2, wherein the high-pass filtering the calculated current direct-axis current value and the calculated current quadrature-axis current value to obtain an alternating-current component in the current direct-axis current and an alternating-current component in the quadrature-axis current corresponding to the permanent magnet synchronous motor comprises:

Y_n＝(X_n-X_n-1+Y_n-1)/(1+T_s*ω_c1)

4. The method according to claim 3, wherein the performing phase compensation processing on the alternating current component in the present direct-axis current and the alternating current component in the present quadrature-axis current to obtain a co-frequency component of the present direct-axis current and a co-frequency component of the present quadrature-axis current corresponding to the permanent magnet synchronous motor comprises:

ω_c2＝ω_e ²/ω_c1ω_e＝(2π*P*n)/60

wherein, ω is_c2Is the firstAngular frequency of two cut-offs, omega_c1The first cutoff angular frequency is defined as P, the number of pole pairs and n, the current number of revolutions;

Y_n＝(T_s*ω_c2*X_n)/(1+T_s*ω_c2)+Y_n-1/(1+T_s*ω_c2)

5. The method of claim 1, wherein calculating the direct-axis voltage command and the quadrature-axis voltage command corresponding to the permanent magnet synchronous motor according to the calculated current direct-axis current value and the calculated current quadrature-axis current value comprises:

6. The method of claim 1, wherein converting the current three-phase current values into current direct-axis current calculated values and current quadrature-axis current calculated values comprises:

7. The method of claim 1, wherein said controlling the permanent magnet synchronous machine according to the target direct axis voltage command and the target quadrature axis voltage command comprises:

substituting the target direct axis voltage command and the target quadrature axis voltage command into an SVPWM (Space vector pulse width modulation) algorithm to calculate the corresponding duty ratio of the permanent magnet synchronous motor;

8. An apparatus for suppressing imbalance in three phase currents, comprising:

9. The apparatus of claim 8, wherein the first computing unit comprises:

10. The apparatus of claim 9, wherein the first processing module comprises:

Y_n＝(X_n-X_n-1+Y_n-1)/(1+T_s*ω_c1)

wherein, Y_nFor the AC component in the present quadrature-axis current, X_nCalculating a value, X, for said current quadrature axis current_n-1Calculating a value for said historical quadrature axis current, Y_n-1For the alternating component in the historical quadrature-axis current, T_sCalculating a period, ω, for said samples_c1For the first cut-off angular frequencyAnd (4) rate.

11. The apparatus of claim 10, wherein the second processing module comprises:

ω_c2＝ω_e ²/ω_c1ω_e＝(2π*P*n)/60

Y_n＝(T_s*ω_c2*X_n)/(1+T_s*ω_c2)+Y_n-1/(1+T_s*ω_c2)

12. The apparatus of claim 8, wherein the first computing unit comprises:

13. The apparatus of claim 8, wherein the conversion unit comprises:

14. A storage medium, characterized in that the storage medium comprises a stored program, wherein when the program is run, the storage medium is controlled to execute the method for suppressing the imbalance of three-phase currents according to any one of claims 1 to 7.

15. An apparatus for suppressing imbalance of three phase currents, said apparatus comprising a storage medium; and one or more processors, the storage medium coupled with the processors, the processors configured to execute program instructions stored in the storage medium; the program instructions when executed perform the method of suppressing a three-phase current imbalance of any one of claims 1 to 7.