Research and Simulation of SCR Soft-Start Asynchronous Motor

Abstract

Direct starting method of asynchronous motor does a lot harm such as current surge and mechanical shock, etc . In order to reduce the harmful influence of direct starting method and improve the starting performance of asynchronous motor, a scheme of asynchronous motor soft starting system based on antiparallel SCR is designed in this paper. Firstly, it analyzes the starting performance of asynchronous motor. Secondly, based on the performance results above, the scheme of three-phase asynchronous motor soft starting system is established. It regulates stator voltage of the motor by SCR regulating system, transformers the synchronous phase voltage to wide pulse wave by trigger module and obtains thyristor gate signal by integrator, so as to achieve the soft-start of asynchronous motor. Finally, by comparing and analyzing the simulation results of direct starting system and soft starting system, it shows that the feasibility and advantages of the SCR type's asynchronous motor soft starting system.