Cross Connected Source based Reduced Switch Count Multilevel Inverter Topology with Fault Tolerance

In this paper, topology of a Cross Connected Source based Reduced Switch Count (CCS-RSC) Multilevel Inverter (MLI) has been analyzed with fault tolerance for a 7-level fed `R' load. The proposed CCS-RSC MLI generates higher voltage levels with optimum number of power switches. The configuration results in an improved power quality by due to reduction in the harmonic content, compared to traditional Multilevel Inverters (MLIs). The CCS-RSC MLI requires only `m+1' power switches for `m' levels, whereas the traditional MLIs require `(2m-1)' switches. Therefore, CCS-RSC inverter requires only eight power switches and three DC sources to generate 7-levels in the output voltage. The redundant switch combinations get limited due to the decrease in power switches. Consequently, the possibility of fault tolerant capability gets effected for a few particular faulty switches. The proposed inverter is analyzed by reconfiguring the switching tables for fault tolerant procedure for an open circuited single switch. Also, the proposed inverter with sine wave reference and inverted sine carrier modulation strategy has a lower %Voltage THD compared to traditional MLI. The effective performance of the suggested topology for a 7-level single-phase CCS-RSC inverter with fault tolerance is validated with MATLAB/SIMULINK for open circuit fault on each of the power switches.