IMPLEMENTATION OF LEVEL SHIFTED MCPWM TECHNIQUE AND OCFT CAPABILITY IN MULTILEVEL INVERTER

Abstract

 five level single phase multilevel inverter is advanced in this paper which remarkably lessens the number of semiconductor devices used, particularly for large number of voltage levels along with open circuit fault tolerance capability. This topology is proposed by using MCPWM technique. When it comes to comparison with other topologies this topology  has reduced number of devices . This topology resembles by some means with CHB (cascaded hybrid bridge). The topology is consist of two DC sources ( each of E1=E2=24V) in such a way that the higher potential side of one DC source  is connected to the lower potential side of another DC source and vice versa. In reduced device count multilevel inverters the redundant states are significantly lowered which influences the fault tolerant ability of multilevel inverters. This study has been done in order to convey fault tolerant quality to reduced device count multilevel inverters. In this paper the OCFT is based on ASSOF (any single switch open circuit fault). Therefore an extra switch is added in order to overcome the fault. The overall topology is simulated and verified through calculated and experimental  results using  software.