Analysis of an IGBT Based AC Chopper Driving RL Load for Oscillation Free Output Voltage

This paper presents detailed analysis of an IGBT based AC chopper for RL load to get oscillation free output along with comparative analysis with conventional chopper. Conventional AC chopper controls power flow through one IGBT without mitigating oscillation of the output. The AC chopper with auxiliary circuit comprises of two IGBTs; one as main to control the output power and another one as auxiliary to remove the oscillating portion from the output. Basic operations of both the choppers are presented. Simulations of the chopper circuits are carried out in MATLAB/Simulink to conform the validation of theoretical analysis. The simulation results are in good agreement with the theoretical expectations. Chopper with auxiliary circuit shows better voltage wave shapes and less THD at the output than conventional one.