Position Sensorless Control Method of Permanent Magnet Motor Based on Mixed Random Signal Injection

Abstract

A hybrid random signal injection-based position sensorless control method of a permanent-magnet motor belongs to the field of position sensorless control of the permanent-magnet motor. Aiming at the problems that a rotor position is acquired by a method of injecting a high-frequency voltage signal between a low speed and zero speed of existing motor running to cause electromagnetic interference and generate relatively large noise, a high-frequency voltage square wave sequence injected to a motor is obtained by a random mode, a phase and a frequency of a voltage signal in the sequence can be acquired by combination after random selection, the sequence is injected to the motor, a response current is extracted, signal processing and extraction is performed on the response current by a high-frequency random demodulation signal to obtain a high-frequency random response current envelope signal comprising position information, and the envelop signal is finally processed to obtain position and rotational speed information. The high-frequency response current obtained by the method is relatively wide in spectrum distribution range, and noise suppression is achieved.

Description

technical field [0001] The invention relates to a position sensorless control method of a permanent magnet motor based on mixed random signal injection, and belongs to the field of position sensorless control of a permanent magnet motor. Background technique [0002] Accurate rotor position information and rotational speed information is the key to realize high-performance vector control of permanent magnet synchronous motor. In traditional permanent magnet motor vector control systems, mechanical position sensors such as encoders are usually used to measure rotor position and speed information for feedback and calculation. However, the existence of the position sensor not only increases the system cost, makes the system structure more complex, but also greatly reduces the reliability of the system operation. At the same time, the use of some high-precision position sensor equipment is easily affected by environmental factors such as atmospheric temperature and moisture con...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the low-speed and zero-speed intervals of the existing motor operation, the method of injecting high-frequency voltage signals to obtain the rotor position will generate electromagnetic interference and generate relatively large noise problems. The present invention provides a permanent Magnetic motor position sensorless control method

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