Method of reducing errors in estimating position and rotating speed of permanent magnet synchronous motor rotor

Abstract

The invention discloses a method of reducing errors in estimating position and rotating speed of a permanent magnet synchronous motor rotor. In sensorless control of a permanent magnet synchronous motor, because various non-ideal factors such as time delay and dead zone function, discrete control of a digital controller and motor parameter asymmetry in switching on and switching off a switch tube of an inverter exist, some periodically changing error components exist in estimating the position and the rotating speed of the rotor, and the errors cause sensorless control performance reduction. Even when the error is relatively large, a system cannot operate normally. The invention provides an error suppression module which is composed of a proportioning link and two integration links. At least one error suppression module is utilized for reducing errors in estimating the position and the rotating speed of the rotor in a permanent magnet synchronous motor sensorless control system based on a fluctuating high-frequency voltage injection method. An estimation error can be remarkably reduced just through low calculation amount. The method improves control performance of the system and furthermore has relatively high application value.

Description

technical field [0001] The invention relates to the field of motor control, in particular to a method for reducing the estimation error of the rotor position and rotational speed of a permanent magnet synchronous motor. Background technique [0002] The position sensorless control of permanent magnet synchronous motor can significantly reduce the volume weight and cost of the system because it does not contain a mechanical position sensor, and many scholars have studied it. [0003] J.H.Jang, S.K.Sul, J.I.Ha, "Sensorless Drive of Surface-Mounted Permanent-Magnet Motor by High-Frequency Signal Injection Based on Magnetic Saliency," IEEE Transactions on Industry Applications, vol.39, no.4, pp.1031-1039, 2003. Proposed the pulse-vibration high-frequency voltage injection method for the first time and applied it to the position sensorless control of surface-mounted permanent magnet synchronous motors. This research injected pulse-vibration high-frequency voltage signals on the d...

AI Technical Summary

Problems solved by technology

This method is less affected by the motor parameters and is simple to implement, but affected by various non-ideal factors, there are certain errors in the estimated position and speed obtained by this method

[0004] At present, there are few related studies on reducing the rotor position and speed estimation errors in the position sensorless control of permanent magnet synchronous motors. Liu Haidong, Zhou Bo, Guo Honghao, Liu Bing, etc. Error Analysis of Pulse Vibration High Frequency Signal Injection Method[J].Electrical Technology Journal of the Chinese Academy of Sciences, 2015, 30(6):38-44. The influence of various parameters of the permanent magnet synchronous motor system on the position estimation error of the pulse vibration high-frequency signal injection method was analyzed, but no specific method for reducing the error was given

In fact, in the position sensorless control of the permanent magnet synchronous motor, due to the existence of various non-ideal factors such as the on-off delay and dead zone of the inverter switch tube, the discrete control of the digital controller, and the asymmetry of the motor parameters, There are some periodically changing error components in the estimated rotor position and estimated speed, these errors make the performance of position sensorless control worse, even when the error is large, the system cannot operate normally

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