Permanent-magnet synchronous electrical machine torque control method

Abstract

The invention provides a permanent-magnet synchronous electrical machine torque control method. When an electrical machine is in a low speed segment, an open loop torque control method is employed to control electrical machine torque, and a corresponding relation between given torque and Q axis currents is obtained via a calibration method and fitted into a curve; the Q axis currents can be directly obtained based on the given torque; when the electrical machine is in a high speed and low intensity magnetic zone, a closed loop torque control method is adopted for estimating output power of a controller via D and Q axis currents and voltage, the output power divided by electrical machine rotating speed is feedback torque, a PI regulator is formed between the feedback torque and the given torque, and output value of the PI regulator is a given Q axis current. The method is not dependent on nominal parameters of the electrical machine; based on operation work conditions of the electrical machine, D and Q axis currents and voltage of the electrical machine can be collected in real time, the output power of the electrical machine controller can be estimated, and a problem that essential electrical machine parameters cannot be accurately reflected via inductance parameters in rated working conditions can be prevented. Via the method, the collected D and Q axis voltage is subjected to time-delay compensation and dead zone compensation, accurate D and Q axis voltage can be obtained, and accurate power estimation can be realized.

Description

technical field [0001] The invention relates to the field of automation control, in particular to a method for controlling the torque of a permanent magnet synchronous motor. Background technique [0002] In recent years, with the rapid development of power electronics technology, microelectronics technology, new motor control theory and rare earth permanent magnet materials, permanent magnet synchronous motors have been rapidly popularized and applied. Compared with the traditional electric excitation synchronous motor, the permanent magnet synchronous motor, especially the rare earth permanent magnet synchronous motor has the advantages of less loss, high efficiency and obvious power saving effect. The permanent magnet synchronous motor provides excitation with permanent magnets, which makes the structure of the motor relatively simple, reduces the cost of processing and assembly, and saves the collector ring and brush that are prone to problems, which improves the reliabi...

AI Technical Summary

Problems solved by technology

In other words, the inductance parameter of the permanent magnet synchronous motor is not constant, but changes with the change of the operating condition of the motor. The inductance parameter at the rated working condition cannot accurately reflect the essence of the motor parameter.

[0004] Starting from the torque equation of a synchronous machine, accurate inductance parameters must be obtained in order to achieve precise torque control, which is difficult to achieve in practical applications

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