Model prediction-direct torque control method for permanent magnet synchronous motor

Abstract

A model prediction-direct torque control method for a permanent magnet synchronous motor belongs to the technical field of control. The object of the invention is to complete the accurate estimation of torque and flux linkage in a system by using a reduced-order observer, and then to design the model prediction-direct torque control method for a permanent magnet synchronous motor of a hub motor drive system controller through a model prediction control algorithm. The steps include: selecting motor torque and flux linkage as state variables, selecting an objective function enabling the minimumerror between a predicted value and an expected value of torque and flux linkage, and obtaining three-phase voltage for controlling the motor to finish control over the PMSM. The model prediction control algorithm applied by the invention can effectively deal with the multi-input multi-output and multi-constraint optimization control problems, replaces a hysteresis loop comparator and a switch selection module of conventional direct torque control, avoids the upper and lower limit pulsation of the hysteresis loop and unnecessary switching losses, and effectively suppresses the torque pulsationof the drive motor.

Description

technical field [0001] The invention belongs to the technical field of control. Background technique [0002] With the improvement of people's quality of life and the rapid development of the automobile industry, the number of automobiles in my country has continued to increase in recent years, and the global non-renewable energy reserves have been continuously consumed, which has seriously threatened energy security, especially the use of a large number of traditional fuel vehicles. deterioration of the environment. Electric vehicles have the advantages of high energy efficiency, zero emissions, and low pollution, and have become the development trend of future automobiles. [0003] The electric vehicle driven by the in-wheel motor is a research hotspot in recent years. The biggest feature of this electric vehicle is that the motor is installed on the wheel of the electric vehicle. The driving torque generated by the motor acts directly on the wheel, which saves the complic...

AI Technical Summary

Problems solved by technology

[0006] 1. The mathematical model of the hub motor is complex, and there are problems such as current coupling and large dependence on motor parameters. The transformation of the current in different coordinate systems increases the amount of calculation of the control system, slows down the dynamic response, and affects the drive of the hub motor. The control effect of the system, especially in the case of sudden traffic changes, if the drive system cannot respond in time, it is easy to cause traffic accidents

[0007] 2. There is a problem of inaccurate estimation of flux linkage. When the control system needs to directly track and control torque and flux linkage, it cannot directly obtain the actual torque and flux linkage values ​​at the current moment through measurement, while torque and flux linkage The estimated deviation of will directly affect the control effect of the in-wheel motor drive system

[0008] 3. The effective control of the three-phase inverter plays a key role in improving the control performance of the motor drive system. Due to the dead time in the actual inverter, it will cause torque and flux linkage errors and increase losses. It may even cause the system to oscillate

Images