Method and device for controlling torque change rate of permanent magnet synchronous motor

Abstract

The invention discloses a method for controlling the torque change rate of a permanent magnet synchronous motor. The method comprises the following steps of a detecting step: detecting the three-phase current and rotary speed of an armature of the motor during operation in real time; a converting step: converting the detected armature three-phase current into a motor alternating-direct axle current based on Clark-Park conversion and calculating a corresponding alternating-direct axle voltage; a torque adjusting step: calculating a modulation factor Mindex based on the alternating-direct current and voltage obtained in the conversion step and adjusting the outputted torques at different torque change rates in a sectional mode according to the range of the modulation factor Mindex value. According to the method and device for controlling the torque change rate of the permanent magnet synchronous motor, a relatively faster torque responding speed is adopted during the control of the maximum torque current ratio, and a relatively smoother torque responding speed is adopted during flux weakening control. The motor is stable in torque outputting, strong in antijamming capacity and fast in accelerated speed and the system is high in brake efficiency. Current impact of the system during high speed can be effectively prevented and the motor in flux weakening control is prevented from being out of control.

Description

technical field [0001] The invention relates to the technical field of motor control, in particular to a method and device for controlling the rate of change of torque of a permanent magnet synchronous motor. Background technique [0002] When designing the permanent magnet synchronous motor (Permanent Magnet Synchronous Motor, PMSM for short) drive system, the torque change rate of the system can be controlled according to the linear curve and the nonlinear curve. Usually, most of the linear curves are selected, and the linear curve is generally a function of setting the torque change rate as a time, such as figure 1 shown. The linear function relationship is relatively simple to deal with, but the acceleration of the system is slow, and it is difficult to meet the requirements of fast start, fast acceleration and effective energy feedback for electric vehicles. There are many types of nonlinear curves, but most of them are complicated to process and the amount of calcula...

AI Technical Summary

Problems solved by technology

However, the current method of using the above-mentioned control strategy to control the torque change rate is not ideal in terms of both dynamic response and stability of the system.

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