Weight-coefficient-free prediction torque control method for permanent magnet synchronous motor

Abstract

The invention provides a weight-coefficient-free prediction torque control method for a permanent magnet synchronous motor, and the method comprises the following steps: sampling a three-phase current, angular velocity and a rotor position angle of the permanent magnet synchronous motor at a moment k, and obtaining an output current and an equivalent counter electromotive force through coordinatetransformation; calculating the outputted voltage vector and stator voltage according to the switching state of a voltage source inverter, and predicting the output current, the stator flux linkage and the stator flux linkage amplitude and torque at a moment k+1 according to the stator voltage; calculating a torque objective function and a stator flux linkage objective function by using the statorflux linkage amplitude and the torque so as to obtain a new objective function; and finally, comparing the values of the objective functions, and using the voltage vector corresponding to the minimumobjective function to control the permanent magnet synchronous motor. The torque and flux linkage objective function is subjected to two-norm standardization, the method achieves the weight-coefficient-free prediction torque control of the permanent magnet synchronous motor, can reduce the system complexity, reduces torque ripples, and improves the torque control precision.

Description

technical field [0001] The invention relates to the field of power electronics, in particular to a non-weight coefficient predictive torque control method for a permanent magnet synchronous motor. Background technique [0002] In recent years, in order to cope with the energy crisis, new energy electric vehicle technology has been vigorously developed. Compared with asynchronous motors, permanent magnet synchronous motors (Permanent Magnet Synchronous Motor, PMSM) have been widely used in the field of electric vehicles because of their high efficiency, high power density and many other advantages. In order to improve the torque dynamic control characteristics of permanent magnet synchronous motors, model predictive control is widely used in the drive control of permanent magnet synchronous motors. However, the conventional predictive torque control method of permanent magnet synchronous motor has the disadvantage of needing to design weight coefficients. Although the liter...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the technical problem of complicated calculation amount existing in the existing permanent magnet synchronous motor torque prediction control method, the present invention proposes a permanent magnet synchronous motor torque prediction control method without weight coefficient, and establishes two parameters of torque and flux linkage. objective function, and a new objective function without weight coefficient was obtained through two-norm standardization, so that the predictive torque control without weight coefficient of permanent magnet synchronous motor was finally realized, which simplified the algorithm complexity and reduced the torque ripple

Images