一种新型可旁路变频软启动器的切换控制方法

摘要

A new type of variable frequency soft starter based on DC switch capacitor and its bypass switching control method were discussed.Large capacity electrolytic capacitor in the main circuit of the traditional frequency converter was replaced by a small capacitor and a small capacitor with switch control,and the problem of energy feedback was solved at the same time of realizing the frequency control.When the inverter was used as soft starter,the rectifier output voltage was directly connected with the inverter side because of the filtering effect of the small capacitance was very small,so as to constitute the circuit condition of the bypass for the variable frequency soft starter,which not only could be applied to the field of motor frequency control but also the field of soft starting,and to achieve the function of variable frequency soft starter bypass exit after motor starting complete.The working principle and by-pass switching method of the new-type of frequency converter are anylyzed,and the feasibility is verified by the MATLAB simulation.%讨论了一种基于直流开关电容的新型变频软启动器及其旁路切换控制方法.将传统变频器主电路中的大容量电解电容用一个小电容和一个带开关控制的小电容代替,在实现变频调速的同时解决了能量回馈问题.当变频器作软启动器使用时,由于使用了滤波作用很小的小电容,使整流输出电压与逆变侧直接相通,从而构成了旁路变频软启动器的电路条件,既可以应用于电机变频调速领域又可以应用于软起动领域,并且在电机起动完成之后实现变频软启动器的旁路退出功能.对新型结构变频器的工作原理以及旁路切换方法进行了研究,并利用MATLAB系统仿真验证了方法的可行性.