CN-121098187-B - Self-adaptive speed control method for single-inverter double-parallel permanent magnet synchronous motor

CN121098187BCN 121098187 BCN121098187 BCN 121098187BCN-121098187-B

Abstract

The invention provides a self-adaptive speed control method for a single-inverter double-parallel permanent magnet synchronous motor, which aims to improve the stability and the anti-interference performance of a single-inverter double-parallel motor driving system. Firstly, establishing an equivalent mathematical model of the system through nonsingular coordinate transformation, and revealing the coupling relation between the output voltage of the inverter and a system control target. On the basis, a basic control framework of the double-parallel motor driving system is constructed by combining the design thought of the back-step controller. Based on a deterministic equivalence principle, the self-adaptive average speed controller is designed, and the robustness of the system to parameter mismatch and load disturbance is remarkably enhanced. The self-adaptive differential speed controller is designed by combining a gradient search method, and the instability risk caused by the singular point of the system is effectively avoided by correcting the online gradient of the gain of the controller.

Inventors

LIN JIANHENG
SUN YAO
YU ZHAOKAI
LI GUI
WANG HAOHAO
PENG GUOBIN
ZHONG MINGSHENG
DAN HANBING
SU MEI

Assignees

中南大学
广东美的暖通设备有限公司

Dates

Publication Date: 20260505
Application Date: 20250820

Claims (1)

1. The self-adaptive speed control method for the single-inverter double-parallel permanent magnet synchronous motor is characterized by comprising the following steps of: Step 1, establishing an equivalent mathematical model of a system through nonsingular coordinate transformation, and revealing a coupling relation between the output voltage of an inverter and a system control target; The mathematical model of the double parallel permanent magnet synchronous motor with the same parameters under the dq rotating coordinate system is as follows: ; Wherein the method comprises the steps of , And Respectively represent the first Complex vector representation of stator current and stator voltage for the dq axis of the table motor; Representing the units of an imaginary number, , And Respectively representing the inductance, resistance and moment of inertia of the parallel motor; And Respectively representing the pole pair number and the flux linkage of the parallel motor; , And Respectively representing the mechanical rotor position, the mechanical rotation speed and the load torque of the kth motor; Defining an average coordinate system And a differential coordinate system The method comprises the following steps: ; The mathematical model of the motor 1 is subjected to coordinate transformation The mathematical model of the motor 2 is subjected to coordinate transformation The equivalent mathematical model of the parallel motor is obtained as follows: ; Wherein the subscript And Representing an average variable and a differential variable, respectively, defined as: ; Variables representing general terms; step 2, combining the design thought of the backstepping controller, constructing a basic control frame of the double parallel motor driving system; From the equivalent model (3-3) of the double parallel motor, the inverter output voltage can only control the average current of the dq axis Based on the design idea of the back-step controller and combining the equivalent models (3-2) and (3-5), the current can be known And Can be used as virtual control input of the average speed loop and the differential speed loop respectively; Step 3, based on a deterministic equivalence principle, a self-adaptive average speed controller is designed, and the robustness of the system to parameter mismatch and load disturbance is improved; the double parallel motor equivalent model (3-2) is rewritten into the form of a state space equation: ; Wherein the method comprises the steps of Is the average speed , Representation of , Representation of , Representation of , Representing the average current on the q-axis , Representing d-axis differential current ; Defining average velocity tracking error ; Wherein the method comprises the steps of Representing an average speed reference value; According to Average velocity tracking error can be obtained The dynamic equation of (2) is: ; Wherein the method comprises the steps of Represented as , Represented as ; Based on the adaptive control deterministic equivalence principle, the average speed controller is designed to: ; Wherein the method comprises the steps of Representation of Is used to determine the adaptive term estimate of (1), Representation of The specific expression of the adaptive term estimation value is as follows: ; Wherein the method comprises the steps of And Respectively representing the adaptive term gains; step 4, designing a self-adaptive differential speed controller by combining a gradient search method, and effectively avoiding the instability risk caused by system singular points through on-line gradient correction of the gain of the controller; The double parallel motor equivalent model (3-5) is rewritten into the form of a state space equation: ; Wherein the method comprises the steps of Is the average speed , Representation of , Representing the d-axis average current , Representing q-axis differential current ; Defining differential velocity tracking error ; Wherein the method comprises the steps of Representing an average speed reference value; According to Differential velocity tracking error can be obtained The dynamic equation of (2) is: ; Wherein the method comprises the steps of Represented as , Represented as ; In combination with the gradient search method, the differential speed controller can be designed as: ; Wherein the method comprises the steps of Indicating the gain of the controller and, And Indicating the gain of the PI controller.

Description

Self-adaptive speed control method for single-inverter double-parallel permanent magnet synchronous motor Technical Field The invention relates to the field of permanent magnet motor drive control, in particular to a self-adaptive speed control method for a single-inverter double-parallel permanent magnet synchronous motor. Background The double parallel motor is widely applied in the fields of double-rotor conveyor belts, industrial robots, rail transit and the like. As a multi-motor driving scheme with compact structure and low cost, a single-inverter-driven double-parallel permanent magnet synchronous motor system gradually becomes a hot spot for multi-motor cooperative control research. However, such systems are susceptible to load disturbances, parameter uncertainties and motor-to-motor coupling effects during operation, resulting in reduced system dynamic performance and possibly even stability problems. Especially when facing to high-performance control requirements, the traditional fixed parameter control method is difficult to consider both the robustness and the dynamic response characteristic of the system, and lacks the self-adaptive adjustment capability for the change of the running state of the system. Furthermore, when the system operates close to the singular point, the control performance is extremely liable to deteriorate, and even the system is unstable in severe cases. Therefore, it is needed to design a dual parallel motor control strategy with control gain adaptive adjustment capability to improve the stability and anti-disturbance performance of the system under complex working conditions. Disclosure of Invention The invention provides a self-adaptive speed control method of a single-inverter double-parallel permanent magnet synchronous motor, which aims to improve the anti-interference performance of a double-parallel motor driving system under the influence of uncertain factors such as load disturbance, parameter mismatch and the like. Meanwhile, the method solves the problem of potential instability caused by system singular points by carrying out online gradient correction on the gain of the controller. In order to achieve the above purpose, the invention provides a self-adaptive speed control method of a single inverter double parallel permanent magnet synchronous motor, comprising the following steps: Step 1, establishing an equivalent mathematical model of a system through nonsingular coordinate transformation, and revealing a coupling relation between the output voltage of an inverter and a system control target; step 2, combining the design thought of the backstepping controller, constructing a basic control frame of the double parallel motor driving system; Step 3, based on a deterministic equivalence principle, a self-adaptive average speed controller is designed, and the robustness of the system to parameter mismatch and load disturbance is improved; And 4, designing a self-adaptive differential speed controller by combining a gradient search method, and effectively avoiding the instability risk caused by system singular points through on-line gradient correction of the gain of the controller. Further, the mathematical model of the double parallel permanent magnet synchronous motor with the same parameters under the dq rotating coordinate system is as follows: ; Wherein the method comprises the steps of ,AndRespectively represent the firstComplex vector representation of stator current and stator voltage for the dq axis of the table motor; Representing the units of an imaginary number, ,AndRespectively representing the inductance, resistance and moment of inertia of the parallel motor; And Respectively representing the pole pair number and the flux linkage of the parallel motor;, And Respectively representing the mechanical rotor position, the mechanical rotation speed and the load torque of the kth motor; Defining an average coordinate system And a differential coordinate systemThe method comprises the following steps: ; The mathematical model of the motor 1 is subjected to coordinate transformation The mathematical model of the motor 2 is subjected to coordinate transformationThe equivalent mathematical model of the parallel motor is obtained as follows: ; Wherein the subscript AndRepresenting an average variable and a differential variable, respectively, defined as: ; Representing a variable that is broadly referred to. Further, as can be seen from the equivalent model (3-3) of the double parallel motor, the inverter output voltage can control only the average current of the dq axisBased on the design idea of the back-step controller and combining the equivalent models (3-2) and (3-5), the current can be knownAndCan be used as virtual control inputs for the average speed loop and the differential speed loop, respectively. Further, the double parallel motor equivalent model (3-2) is rewritten into the form of a state space equation: ; Wherein the method comprises the st