Hybrid Diodes & MOSETs for Three Phase Half Wave Controlled Rectifier

Abstract

Power electronics is an application that is used to control and convert electrical power from one form to another using electronic components, for example three-phase half-wave-controlled rectifier, generally uses SCRs, its output voltage can be controlled by adjusting the delay angles of SCRs. In this research, SCRs can be replaced with hybrid silicon diodes and MOSFETs, its control system is designed by using electronic components such as op-amps, AND gates, and several other basic electronics components, and used low voltage so that three-phase input voltage must be lowered by using transformer in a star connection and then connected to three phase half wave rectifier circuit. To compare the output of a three-phase half-wave rectifier with Vref is needed comparator 1, this circuit aims to get the starting point of the triangular wave that is produced from the triangle wave circuit exactly at the cross-over point of the three-phase voltage wave, to control the MOSFET S1 delay angle can be done by adjusting the Vangles on the comparator 2, while the Sa, Sb, and Sc are activated by the comparator 3 and the AND gate circuit. Based on the simulation results by using a computer, this hybrid circuit output voltage approximates to the SCRs circuit with a resistive load, thus this proposed circuit can be an alternative to a replacement conventional circuit that uses SCRs.

Keywords: Three-phase controlled rectifier, SCR, Hybrid Silicon Diodes and MOSFETs, Op-Amp, delay angles