Field weakening control system and method for permanent magnet synchronous motor

Abstract

The invention provides a field weakening control system and a field weakening control method for a permanent magnet synchronous motor. The invention relates to the technical field of motor speed regulation control. The invention is characterized in that the method comprises the steps of obtaining related motor parameters, analyzing and calculating a flux-weakening current prediction value in advance through a permanent magnet synchronous motor formula, continuously obtaining the current output voltage, comparing the current output voltage with a voltage limit value, carrying out weak magneticcurrent iterative correction to obtain a weak magnetic current correction value, and outputting a comprehensive weak magnetic current given value according to the correction value, the prediction value and a direct-axis current given value, thereby realizing field weakening control of the permanent magnet synchronous motor. According to the invention, the field weakening control response is fast,the stability is high, the instability of the control system is reduced, the parameter modulation difficulty in the field weakening control is avoided, and the efficiency of the field weakening control is improved.

Description

technical field [0001] The invention relates to the technical field of motor speed regulation control, in particular to a field weakening control system and a control method for a permanent magnet synchronous motor. Background technique [0002] With the development of the motor speed control industry, permanent magnet synchronous motors are being used more and more due to their advantages such as high power density and high efficiency. In the occasions that require high-speed operation of the motor, the field-weakening speed regulation performance of the permanent magnet synchronous motor has also received more and more attention. [0003] At present, there are two common field weakening control methods for permanent magnet synchronous motors. One is through the engineering calibration method, which is to carry out detailed calibration of the torque, speed and current data of the field weakening operation area of ​​the permanent magnet motor, and obtain the current given ac...

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Problems solved by technology

[0003] At present, there are two common field weakening control methods for permanent magnet synchronous motors. One is through the engineering calibration method, which is to carry out detailed calibration of the torque, speed and current data of the field weakening operation area of ​​the permanent magnet motor, and obtain the current given according to the calibration data. Fixed interpolation table to obtain given value of field weakening current and torque current. This way of field weakening calibration has a large workload, and the calibration data can only be used to calibrate the motor, which has poor versatility.

Another way is to adjust the error between the current loop control output value and the system output voltage limit, and adjust the output value as the given value of the field-weakening current. This method does not depend on the calibration data and has good versatility. However, the parameters of the field-weakening regulator It is not easy to choose, and the torque and speed dynamic adaptability to control operation in the field weakening area is relatively poor, and the system is prone to stability problems

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