CN-119945232-B - Maximum torque current ratio control method and system for double three-phase permanent magnet synchronous motor based on virtual signal injection

Abstract

The invention discloses a control method and a control system for the maximum torque current ratio of a double three-phase permanent magnet synchronous motor based on virtual signal injection, which are characterized in that bipolar square wave signals are injected into current vector angles, and d-q axis currents after the bipolar square wave signals are injected are calculated by using the current vector angles of the bipolar square wave signals; substituting d-q axis current injected with bipolar square wave signals into a corrected torque equation, calculating positive polarity torque T e up and negative polarity torque T e down of the double three-phase permanent magnet synchronous motor, expanding according to the Taylor series, when the difference between T e up and T e down of the Taylor series expansion is equal to 0, superposing the difference between T e up and T e down with an initial current vector angle beta after passing through a PI controller to obtain a current optimal current vector angle, and calculating d-q axis reference current required by the double three-phase permanent magnet synchronous motor. The invention realizes the accurate control of the maximum torque current ratio.

Inventors

• ZHAO WENXIANG
• WANG JIANYE
• JI JINGHUA
• TAO TAO
• KANG MEI
• LING JINCHENG
• CHEN YIFAN

Assignees

• 江苏大学

Dates

Publication Date

20260512

Application Date

20250115

Claims (5)

1. 1. A control method for the maximum torque current ratio of a double three-phase permanent magnet synchronous motor based on virtual signal injection is characterized by comprising the following steps: Injecting a bipolar square wave signal into a current vector angle; Calculating d-q axis current after the bipolar square wave signal is injected by using a current vector angle of the bipolar square wave signal; Substituting d-q axis voltage, d-q axis current before bipolar square wave signal is injected, d-q axis current after bipolar square wave signal is injected and electric angular velocity omega e into a corrected torque equation, calculating positive polarity torque T e up and negative polarity torque T e down of the double three-phase permanent magnet synchronous motor, and expanding according to Taylor series, wherein the difference between T e up and T e down of Taylor series expansion is used as a judging condition of the maximum torque current ratio, when the difference between T e up and T e down of Taylor series expansion is equal to 0, the difference between T e up and T e down is overlapped with an initial current vector angle beta after passing through a PI controller to obtain a current optimal current vector angle, and calculating d-q axis reference current required by the double three-phase permanent magnet synchronous motor, thereby realizing integral closed-loop control; The bipolar square wave signal is: wherein, delta represents the amplitude of the injected signal, T s represents one signal period, and N represents a natural number set; the current vector angle after the bipolar square wave signal is injected is as follows: the d-q axis current after the bipolar square wave signal is injected is as follows: Wherein I s represents the stator current amplitude; The corrected torque equation is obtained by correcting the torque equation by using a double three-phase permanent magnet synchronous motor mathematical model, and specifically comprises the following steps: Wherein i d up 、i q up represents d-axis current and q-axis current after positive polarity square wave signal injection, i d down 、i q down represents d-axis current and q-axis current after negative polarity square wave signal injection, n p represents motor pole pair number, u d and u q represent d-axis voltage and q-axis voltage, i d and i q represent d-axis current and q-axis current before bipolar square wave signal injection, R is stator resistance, ω e is electrical angular velocity, L d represents d-axis stator inductance, and δ represents amplitude of injection signal.
2. 2. The method for controlling the maximum torque-to-current ratio of a double three-phase permanent magnet synchronous motor according to claim 1, wherein the difference between the positive polarity torque and the negative polarity torque of the taylor series expansion is 。
3. 3. The method for controlling the maximum torque current ratio of the double three-phase permanent magnet synchronous motor according to claim 1, wherein the d-q axis reference current required by the double three-phase permanent magnet synchronous motor is: where β' is the optimal current vector angle.
4. 4. The method for controlling the maximum torque current ratio of the double three-phase permanent magnet synchronous motor according to claim 1, wherein the bipolar square wave signal comprises a positive polarity square wave and a negative polarity square wave, and the duty ratio of the positive polarity square wave and the negative polarity square wave is 50%.
5. 5. A system for implementing the method for controlling the maximum torque-to-current ratio of a double three-phase permanent magnet synchronous motor according to any one of claims 1 to 4, comprising: the virtual signal injection module is used for realizing bipolar virtual square wave signal injection; The signal demodulation module is used for obtaining an optimal current vector angle; and the rotating speed controller is used for acquiring d-q axis reference current required by the double three-phase permanent magnet synchronous motor.

Description

Maximum torque current ratio control method and system for double three-phase permanent magnet synchronous motor based on virtual signal injection Technical Field The invention belongs to the field of multiphase permanent magnet synchronous motor drive control application, and particularly relates to a method and a system for controlling the maximum torque current ratio of a double three-phase permanent magnet synchronous motor based on virtual signal injection. Background With the rapid development of high-end fields such as transportation, aerospace, national defense and military industry and the like, the motor and a control system thereof are used as core components of equipment, and the operation performance requirement is further improved. The multiphase permanent magnet synchronous motor consists of two key components, namely a multi-polarization permanent magnet rotor and a stator with windings. Because of the advantages of high efficiency, large torque, small volume and the like, the device plays an important role in the operation control in the industrial automation field. A significant feature of the built-in permanent magnet synchronous motor compared to a surface-mounted permanent magnet synchronous motor is that the inductance difference is large, i.e. the q-axis inductance is significantly larger than the d-axis inductance, and this difference between q-axis inductance and d-axis inductance contributes to the generation of additional torque, called reluctance torque. Therefore, the torque generated in the interior permanent magnet synchronous motor is composed of permanent magnet torque and reluctance torque from the permanent magnets. The maximum torque current ratio (MTPA) control method is a mode for realizing maximum utilization torque, and can be used for effectively reducing copper loss by having a current vector with minimum amplitude among various current vectors of specific torque. Chinese patent CN118842365A discloses an MTPA control method using an extremum searching algorithm, which searches for a proper motor direct axis current value by using a feedback current vector amplitude of a motor through the extremum searching algorithm, so that the current amplitude reaches a minimum value, and finally realizes MTPA control. Chinese patent CN118801747a discloses an improved MTPA control method, in which in the electromagnetic torque formula of a permanent magnet synchronous motor, the change rate of electromagnetic torque along with the current angle is zero by using the extremum principle, and the extremum point of electromagnetic torque is determined, and the corresponding current angle is the MTPA working point, so as to realize the control of the maximum torque current ratio. Chinese patent CN117978030a discloses a constant parameter MTPA control method, which increases an error term between a motor real-time running MTPA curve and a set MTPA curve value in an established cost function, and compared with the traditional piecewise solution, the method simplifies a calculation method, and simultaneously provides a system model for solving a permanent magnet synchronous motor model predictive cost function. However, these methods mainly consider the implementation of MTPA control, and do not further analyze the dynamic response capability and the current angle error. In order to further improve the control performance of the multiphase permanent magnet synchronous motor, the development of MTPA control with rapidity and accuracy is of great significance. Disclosure of Invention In view of the above, the invention provides a method and a system for controlling the maximum torque current ratio of a double three-phase permanent magnet synchronous motor based on virtual signal injection, which are different from the traditional method based on sinusoidal signal injection. The present invention achieves the above technical object by the following means. A control method for maximum torque current ratio of a double three-phase permanent magnet synchronous motor based on virtual signal injection comprises the following steps: Injecting a bipolar square wave signal into a current vector angle; Calculating d-q axis current after the bipolar square wave signal is injected by using a current vector angle of the bipolar square wave signal; substituting d-q axis voltage, d-q axis current before bipolar square wave signal is injected, d-q axis current after bipolar square wave signal is injected and electric angular velocity omega e into a corrected torque equation, calculating positive polarity torque T eup and negative polarity torque T edown of the double three-phase permanent magnet synchronous motor, expanding according to Taylor series, taking the difference between T eup and T edown of Taylor series expansion as a judgment condition of maximum torque current ratio, and when the difference between T eup and T edown of Taylor series expansion is equal to 0, superposing the difference between T