阅读说明：本技术 一种永磁电机的控制方法 (Control method of permanent magnet motor ) 是由 吴立建 方攸同 李卓航 陈泽开 朱亮 于 2019-12-25 设计创作，主要内容包括：一种永磁电机的控制方法,包含了电机不平衡状态判断模块,坐标变换数学模型,和不平衡谐波电流抑制模块,不平衡谐波电流模块完成后,电机运行状态再次输入电极不平衡状态判断模块中。本发明的优点在于：能够针对所有双三相电机进行不平衡状态判断,获得不平衡运行参数,有效抑制不平衡电流成分,减小不平衡运行状态下的转矩脉动。(A control method of a permanent magnet motor comprises a motor unbalance state judgment module, a coordinate transformation mathematical model and an unbalance harmonic current suppression module, wherein after the unbalance harmonic current module is completed, the running state of the motor is input into the electrode unbalance state judgment module again. The invention has the advantages that: the method can judge the unbalanced state of all the double three-phase motors to obtain unbalanced operation parameters, effectively inhibit unbalanced current components and reduce torque pulsation in the unbalanced operation state.)

1. A control method of a permanent magnet motor comprises a motor unbalance state judgment module, a coordinate transformation mathematical model and an unbalance harmonic current suppression module, wherein after the unbalance harmonic current module is finished, the running state of the motor is input into the electrode unbalance state judgment module again;

the unbalance state judging module distinguishes the unbalance state of the motor, wherein the unbalance state comprises an unbalance operation state after single-phase circuit breaking, an unbalance operation state when only one set of windings operates, and asymmetric resistance and inductance parameters; the coordinate transformation mathematical model comprises a double dq0 transformation unit, a vector decoupling transformation unit and an improved vector decoupling transformation unit; when the motor is in an unbalanced operation state when only one set of windings operates, the double dq0 conversion unit is adopted to carry out coordinate conversion on the operation parameters of the motor; when the motor is in an unbalanced operation state after single-phase circuit break or the parameters of resistance and inductance are asymmetric, the unbalanced operation information of the motor, including the magnitude of harmonic current and the current difference value between two windings, is obtained by adopting VSD or improved vector decoupling transformation.

2. The control method of a permanent magnet motor according to claim 1, characterized in that: the transformation matrix of the VSD unit is:

wherein, theta represents the included angle of the electrical angle between the d axis of the rotating coordinate system and the A axis of the static coordinate system.

3. The control method of a permanent magnet motor according to claim 1, characterized in that: the improved vector decoupling transformation matrix is:

4. the control method of a permanent magnet motor according to claim 1, characterized in that: the unbalanced harmonic current suppression module is a proportional-integral resonance controller and/or a harmonic voltage feedforward algorithm, and when the proportional-integral resonance controller and the harmonic voltage feedforward algorithm are adopted for mixed suppression, the proportional-integral resonance controller and the harmonic voltage feedforward algorithm are used in parallel.

5. The control method of a permanent magnet motor according to claim 1, characterized in that: the coordinate transformation mathematical model is loaded or integrated in the motor controller as a calculation module, or the coordinate transformation mathematical model is integrated in a remote controller or calculation resources of the motor as a calculation module; and or, the coordinate transformation mathematical model comprises a model calling unit, and the model calling unit calls the corresponding mathematical model to calculate according to the judgment result of the unbalance state.

6. A control method of a permanent magnet motor performs the following operations: identifying the unbalanced state of the motor and classifying the unbalanced state, wherein the unbalanced state comprises an unbalanced running state after single-phase circuit break, an unbalanced running state when only one set of winding runs, and asymmetric resistance and inductance parameters; carrying out coordinate transformation on the motor operation parameters to obtain unbalanced specific parameters, such as unbalanced current components, unbalanced current harmonics and the like; the coordinate transformation mathematical model comprises double dq0 transformation, vector space decoupling transformation and an improved vector decoupling transformation matrix, and when the motor is in an unbalanced running state when only one set of windings run, the double dq0 transformation is adopted to carry out coordinate transformation on the running parameters of the motor; when the motor is in an unbalanced operation state after single-phase circuit break or the parameters of resistance and inductance are asymmetric, coordinate transformation is carried out by adopting VSD or an improved vector decoupling transformation matrix, and the unbalanced operation information of the motor is obtained by coordinate transformation; inputting unbalanced operation information into an unbalanced harmonic current suppression module, and inputting the current operation state of the motor into an electrode unbalanced state judgment module again after the unbalanced harmonic current suppression module finishes suppression; the unbalance state determination, the coordinate transformation, and the unbalance harmonic current suppression are repeatedly performed.

Technical Field

The invention belongs to the field of motor control, and relates to a control method under the condition of unbalance of a double three-phase permanent magnet synchronous motor.

Background

A permanent magnet synchronous motor is a synchronous rotating motor excited by permanent magnets. It has the advantages of high power density, high efficiency, various structures and the like. The multiphase permanent magnet synchronous motor is widely applied to the fields of ship electric power, aviation electric power, wind power generation and the like due to the characteristics of fault-tolerant operation, high reliability and the like.

The double three-phase permanent magnet synchronous motor with two sets of windings is mainly divided into a double-winding motor with 30-degree phase shift and a double-winding motor without phase shift. Each set of windings of the double-winding motor with the phase shift of 30 degrees is completely symmetrical in space structure. Each set of windings of the phase-shift-free double-winding motor may not be completely symmetrical in space structure, which may result in asymmetric mutual inductance. Under the condition of phase-loss fault operation (namely when one set of windings is cut off due to faults and does not operate any more, only one set of windings operates normally), the motor structure can have unbalanced operation condition. Meanwhile, the problems of motor manufacturing process, non-linear characteristic of a driver and long-term running aging can cause the electrical parameter matrix of the motor to be asymmetric, and the motor has unbalanced running condition.

The double three-phase motor operates under the unbalanced condition, vibration noise can be increased, and the service life of the motor is influenced. Therefore, how to restrain the unbalanced operation of the motor and reduce the torque pulsation has important significance.

At present, researches for inhibiting unbalanced operation of a motor mainly aim at a double-winding motor with a phase shift of 30 degrees, and no scheme for judging and inhibiting unbalanced operation of the double-winding motor without the phase shift is published.

Disclosure of Invention

The invention aims to provide a double three-phase permanent magnet synchronous motor unbalance control system and method which can judge the unbalance state of all double three-phase motors, obtain unbalance operation parameters, effectively inhibit unbalance current components and reduce torque pulsation in the unbalance operation state.

A double three-phase permanent magnet synchronous motor unbalance control system comprises a motor unbalance state judgment module, a coordinate transformation mathematical model and an unbalance harmonic current suppression module, wherein after the unbalance harmonic current module is finished, the running state of a motor is input into an electrode unbalance state judgment module again;

the unbalance state judging module distinguishes the unbalance state of the motor, wherein the unbalance state comprises an unbalance operation state after single-phase circuit breaking, an unbalance operation state when only one set of windings operates, and asymmetric resistance and inductance parameters; the coordinate transformation mathematical model comprises double dq0 transformation units, VSD (vector space decoupling transformation) units and a modified vector decoupling transformation matrix; when the motor is in an unbalanced operation state when only one set of windings operates, the double dq0 conversion unit is adopted to carry out coordinate conversion on the operation parameters of the motor; and when the motor is in an unbalanced operation state after single-phase circuit break or the parameters of the resistance and the inductance are asymmetric, performing coordinate transformation by adopting the VSD or the improved vector decoupling transformation matrix, and obtaining unbalanced operation information of the motor through coordinate transformation.

The unbalanced operation information includes harmonic currents and a current difference value between the two phase windings.

Preferably, the transformation matrix of the VSD unit is:

，

wherein, theta represents the included angle of the electrical angle between the d axis of the rotating coordinate system and the A axis of the static coordinate system.

As a preferred scheme, the improved vector decoupling transformation matrix is:

preferably, the unbalanced harmonic current suppression module is a proportional-integral resonance controller (PIR) and/or a harmonic voltage feedforward algorithm, and when the proportional-integral resonance controller (PIR) and the harmonic voltage feedforward algorithm are adopted for hybrid suppression, the proportional-integral resonance controller (PIR) and the harmonic voltage feedforward algorithm are used in parallel.

Preferably, the coordinate transformation mathematical model is loaded or integrated in the motor controller as a calculation module, or the coordinate transformation mathematical model is integrated in a remote controller or a calculation resource of the motor as a calculation module; and or, the coordinate transformation mathematical model comprises a model calling unit, and the model calling unit calls the corresponding mathematical model to calculate according to the judgment result of the unbalance state.

A double three-phase permanent magnet synchronous motor unbalance control method executes the following operations: identifying the unbalanced state of the motor and classifying the unbalanced state, wherein the unbalanced state comprises an unbalanced running state after single-phase circuit break, an unbalanced running state when only one set of winding runs, and asymmetric resistance and inductance parameters;

carrying out coordinate transformation on the motor operation parameters to obtain unbalanced specific parameters, such as unbalanced current components, unbalanced current harmonics and the like; the coordinate transformation mathematical model comprises a double dq0 transformation unit, a VSD (vector space decoupling transformation) unit and an improved vector decoupling transformation matrix, and when the motor is in an unbalanced operation state when only one set of windings operate, the double dq0 transformation unit is adopted to carry out coordinate transformation on the operation parameters of the motor; when the motor is in an unbalanced operation state after single-phase circuit break or the parameters of resistance and inductance are asymmetric, VSD is adopted or coordinate transformation is carried out, and the unbalanced operation information of the motor is obtained through the coordinate transformation;

inputting unbalanced operation information into an unbalanced harmonic current suppression module, and inputting the current operation state of the motor into an electrode unbalanced state judgment module again after the unbalanced harmonic current suppression module finishes suppression; the unbalance state determination, the coordinate transformation, and the unbalance harmonic current suppression are repeatedly performed.

The unbalanced operation information comprises harmonic current of the two-phase winding and parameter difference values of the two-phase winding when the two-phase winding is unbalanced.

The technical concept of the invention is as follows: firstly, the motor unbalance state judging module judges which type of unbalance operation problem exists in the current circuit by detecting current circuit current, voltage, power device fault signals and other data. Then, based on the problem of unbalanced operation, an appropriate coordinate transformation mathematical model is selected. And finally, suppressing the unbalanced harmonic current in the double three-phase motor by adopting a proportional integral resonance controller (PIR), harmonic voltage feedforward or a mixed control algorithm of the proportional integral resonance controller and the harmonic voltage feedforward.

The unbalanced operation reasons of the double-winding permanent magnet synchronous motor are as follows: 1. when the motor body is designed, the spatial structure of a single set of windings is asymmetric, so that the mutual inductance of each set of windings is unbalanced; 2. parameters such as resistance, inductance and the like of the motor are asymmetric due to the motor manufacturing process, the nonlinear characteristic of a driver, the long-term operation aging problem and the like. Therefore, the motor unbalance state judgment module can classify the following three unbalance states: 1. an unbalanced operating state after single-phase disconnection; 2. an unbalanced state when only one set of three-phase windings is running; 3. the parameters of resistance and inductance in the double three-phase motor are asymmetric. The first unbalanced state is caused by single-phase short circuit, open circuit and other faults, and after the short-circuit fault phase or the open circuit fault phase is cut off, the fault can be regarded as open circuit fault, and the rest phases continue to operate. In order to ensure that the resultant magnetic field generated by the current is constant in the magnetic flux linkage circle of the space, the current of the excision phase is shared by the rest phases. If the motor winding structure is asymmetric, a negative-sequence current will occur in this case. The second unbalanced condition is that a single phase or multiple phases in one set of windings are in fault, and after the whole set of windings are cut off, the other set of three-phase windings continue to operate. If the motor winding structure is asymmetric, negative-sequence currents will also occur in this case. The third unbalanced state is that the motor parameter matrix is asymmetric and negative sequence current occurs when rated operation is performed due to different resistance and inductance parameters of each phase of motor.

The mathematical model of coordinate transformation used in motor control can use the traditional double dq0 transformation, and also: 1. a vector space decoupling transform (VSD); 2. a new vector decoupling transformation matrix; 3. a double dq0 transform. The first coordinate transformation model, VSD, is suitable for the neutral point connection or the isolated double three-phase motor of neutral point, regard the double three-phase motor as the six-phase motor, through the decoupling transformation matrix of vector space to vary the six-phase parameter into the six-phase orthogonal decoupling parameter, wherein two-phase parameters form the space vector of fundamental wave sub-plane, two-phase parameters form the space vector of harmonic sub-plane, two-phase parameters form the space vector of zero sequence sub-plane. The second kind of coordinate transformation model, new vector decoupling transformation matrix, is to transform the six variables of the double three-phase motor into four unbalanced components of the dq axis component and the zero sequence plane of the fundamental plane, the dq axis component controls the electromechanical transformation of the motor, and the unbalanced component controls the unbalance of each phase between two windings of the motor. And a third coordinate transformation model, namely double dq0 transformation, is suitable for a double-winding motor with isolated neutral points, two sets of windings are regarded as vector composition of two three-phase motor subsystems, and Clarke-Park coordinate transformation is respectively carried out on each set of windings.

When the motor runs in an unbalanced state, a proportional integral resonant controller (PIR), a harmonic voltage feedforward algorithm or a mixed control algorithm of the PIR and the harmonic voltage are adopted to restrain unbalanced components in current. The unbalanced component in the current is dominated by the negative sequence current (double frequency harmonic current) component caused by the asymmetry of the electrical parameters.

In the first method, a PI controller is connected in parallel with a resonance controller, the PI controller can track a direct current component in a current, and the resonance controller is used for suppressing a harmonic current of a specific frequency by generating a harmonic component of the frequency in a high-gain tracking current of the frequency. The second method, harmonic voltage feedforward, calculates the harmonic voltage component Δ of the suppressed harmonic current based on the determined motor parameter imbalance componentU _d 、ΔU _q Is injected intoU _d 、U _q In the method, harmonic current suppression is rapidly realized. In a third method, the PIR controller is used in combination with a harmonic voltage feed forward algorithm while suppressing unbalanced currents in the circuit. The harmonic voltage feedforward can ensure the current to be quickly restrained and improve the restrained dynamic response. If the unbalanced component of the motor parameter can be accurately measured, the compensation harmonic voltage component can be accurately injected, and the harmonic current can be completely inhibited. A resonance term in the PIR controller is provided with an integrator, so that the harmonic current in the current under a steady state can be controlled to be 0, and the complete inhibition on the harmonic current is realized under the condition that the measurement of the unbalanced component of the motor parameter is inaccurate. Therefore, the PIR and harmonic voltage feedforward hybrid algorithm can realize the rapid and complete suppression of the unbalanced harmonic current.

The motor unbalance state judgment module is used for positioning the unbalance problem, and a proper coordinate transformation mathematical model and an unbalance current suppression method are selected, so that the suppression of the unbalance current component in the motor system is realized. Because the double three-phase permanent magnet synchronous motor has various winding arrangement structures, the unbalance problem is more, and the invention can judge various unbalance conditions and solve the unbalance problem in a targeted manner. Compared with a traditional double three-phase motor coordinate transformation mathematical model, the invention provides a new coordinate transformation model. Compared with the traditional PIR controller and harmonic voltage feedforward hybrid algorithm, the invention adopts the PIR and harmonic voltage feedforward hybrid algorithm, and can improve the dynamic and steady-state performance of the unbalanced current suppression algorithm.

Drawings

FIG. 1 is a flow chart of the operation of the present invention.

Fig. 2 is a winding distribution structure diagram of two double-winding three-phase motors, wherein a is a winding distribution structure diagram with a phase shift of 30 degrees, and b is a winding distribution structure diagram without a phase shift.

Fig. 3 is a schematic diagram of three types of classification for imbalance determination.

FIG. 4 is a control block diagram for coordinate transformation using a modified vector decoupling transformation matrix with PIR suppression of unbalanced current harmonics.

Fig. 5 is a graph comparing current waveforms in the motor before and after the control strategy of fig. 4 is applied.

FIG. 6 is a control block diagram for hybrid suppression of unbalanced current harmonics using PIR and harmonic voltage feedforward algorithms using dual dq0 for coordinate transformation.

FIG. 7 is a graph comparing current waveforms in the motor before and after the control strategy of FIG. 6 is employed.

Fig. 8 is a control block diagram for performing coordinate conversion using the VSD and suppressing an unbalanced current harmonic using the PIR.

FIG. 9 is a graph comparing current waveforms in the motor before and after the control strategy of FIG. 8 is employed.

Fig. 10 is a schematic diagram of the directional component of the current vector in the flux linkage vector.

FIG. 11 is a schematic of a current vector decomposition to the dq axis.

FIG. 12 is a schematic diagram of six-phase current values in an alpha-beta coordinate system.

FIG. 13 is a schematic diagram of the integration of dq coordinate system into alpha-beta coordinate system.

FIG. 14 is a schematic diagram showing the integration of the dq coordinate system into the alpha-beta coordinate system when the alpha axis and the d axis coincide with each other.

Detailed Description

The invention is further illustrated by the following figures and examples.

The embodiment and the attached drawings illustrate a motor unbalance state judgment module, three coordinate transformation mathematical models and a proportional integral resonant controller (PIR) and harmonic voltage feedforward mixed suppression method. The invention is also suitable for multi-phase and multi-set winding motors, and the control principle is the same.

Fig. 1 is a block diagram illustrating an implementation flow of a control strategy under unbalanced operation. The double-winding motor has the problems of unbalanced operation condition, unbalanced negative sequence current and increased torque pulsation due to the problems of structural design, manufacturing process, operation failure, aging and the like of the motor body.

Fig. 2 shows two main winding arrangements of a double three-phase permanent magnet synchronous machine, (a) the winding arrangement 1 is phase-shifted by 30 ° and (b) the winding arrangement 2 is phase-shifted. In the winding distribution structure 2, each set of windings cannot be completely symmetrical in space, so that an inductance matrix of each set of windings is asymmetrical, and unbalanced current can occur under the condition that currents of two sets of windings are not completely consistent.

As shown in fig. 1, a method for controlling imbalance of a dual three-phase permanent magnet synchronous motor performs the following operations: identifying the unbalanced state of the motor and classifying the unbalanced state, wherein the unbalanced state comprises an unbalanced running state after single-phase circuit break, an unbalanced running state when only one set of winding runs, and asymmetric resistance and inductance parameters;

carrying out coordinate transformation on the motor operation parameters to obtain unbalanced specific parameters, such as unbalanced current components, unbalanced current harmonics and the like; the coordinate transformation mathematical model comprises a double dq0 transformation unit, a VSD (vector space decoupling transformation) unit and an improved vector decoupling transformation matrix, and when the motor is in an unbalanced operation state when only one set of windings operate, the double dq0 transformation unit is adopted to carry out coordinate transformation on the operation parameters of the motor; when the motor is in an unbalanced operation state after single-phase circuit break or the parameters of resistance and inductance are asymmetric, VSD is adopted or coordinate transformation is carried out, and the unbalanced operation information of the motor is obtained through the coordinate transformation;

inputting unbalanced operation information into an unbalanced harmonic current suppression module, and inputting the current operation state of the motor into an electrode unbalanced state judgment module again after the unbalanced harmonic current suppression module finishes suppression; the unbalance state determination, the coordinate transformation, and the unbalance harmonic current suppression are repeatedly performed.

As shown in fig. 2, the motor imbalance state determination module takes the 6-phase current, the 6-phase end voltage, and the fault signal of each bridge arm of the driving module of the dual three-phase motor as input. If the IGBT driving module has a bridge arm fault, the problems of phase short circuit, open circuit and the like are judged, and the fault phase is cut off. And if only one phase is cut off, performing a single-phase open circuit control strategy. And if two phases are cut off and the two phases are the same set of winding, carrying out a single set of three-phase winding control strategy. And if the IGBT driving module has no bridge arm fault signal and obvious negative sequence current component appears in the 6-phase current, carrying out asymmetric control on the resistance and the inductance.