同步电机静止变频软起动及其电枢电流谐波分析

Static frequency soft start of synchronous motor and analysis of armature current harmonics

同步电机软起动是由静止变频器(Static Frequency Converter,SFC)将同步电机从静止逐渐拖动至额定转速。但SFC短时和频繁起动会造成大量谐波,该谐波施加在同步电机电枢绕组对同步电机造成不可逆的危害。本文首先图解分析了同步电机软起动低速和高速阶段的换相过程,由此推导出各阶段电枢电流模型,从而分析得出电枢电流谐波特性。最后,搭建出同步电机软起动的Matlab/Simulink模型,验证本文推导的准确性。

Synchronous motor soft start is achieved by gradually dragging the synchronous motor from stationary to rated speed using a Static Frequency Converter(SFC).However,short-term and frequent starting of SFC can cause a large number of harmonics,which are applied to the armature winding of the synchronous motor and cause irreversible harm to the motor.This article first illustrates and analyzes the commutation process in the low-speed and high-speed stages of synchronous motor soft start,and derives the armature current models for each stage,thereby analyzing the harmonic characteristics of the armature current.Finally,a Matlab/Simulink model for soft starting of synchronous motors was constructed to verify the accuracy of the derivation in this paper.