Compensation method and compensation device for permanent magnet motor

Abstract

The invention provides a compensation method and a compensation device for a permanent magnet motor. The compensation method includes S1, detecting response current of the permanent motor, and counting rotor speeds and load signals of the permanent motor according to the response current; S2, detecting torque cycles of the permanent motor if the rotor speeds are lower than preset speeds; S3, counting loading torque fluctuation ranges in the torque cycles according to the load signals; and S4, when deviation values of the loading torque fluctuation ranges and rotor motor torque fluctuation ranges exceed preset threshold values, counting compensating voltage for a rotor Q axle according to the deviation values of the average values and the actual values of the loading torque fluctuation ranges, and adding the compensating voltage into each torque cycle. According to torque change rules of the permanent motor load in each mechanical rotation cycle, torque compensating signals are fed forwardly to a torque ring, so that torque changes can be adjusted timely, speed is stabled and vibration is reduced.

Description

technical field [0001] The invention relates to a low-speed compensation method and device for a permanent magnet motor, in particular to a low-speed compensation method and device for a permanent magnet motor used in a compressor. Background technique [0002] Due to the advantages of high power density and high efficiency, permanent magnet motors are widely used in many occasions, such as refrigerator compressors. [0003] When the compressor is running, the torque of the permanent magnet motor always changes due to the different loads of the compression process and the release process of each compression cycle. The traditional control method is to adjust after the torque changes, so the torque control always lags behind the load change, which will cause the compressor speed to fluctuate and produce mechanical vibration. Contents of the invention [0004] In order to solve the above technical problems, the object of the present invention is to provide a low-speed compen...

AI Technical Summary

Problems solved by technology

The traditional control method is to adjust after the torque changes, so the torque control always lags behind the load change, which will cause the compressor speed to fluctuate and produce mechanical vibration

Images