An Optimized Selective Harmonic Minimization-PWM Scheme for Cascaded H-Bridge Inverter Fulfilling NRS 048-2:2003 Grid code

This paper presents, an optimized pulse width modulation (PWM) scheme for a five-level cascaded H-bridge (CHB) inverter that minimizes some selective harmonics to fulfill the grid code NRS 048-2:2003 for medium-voltage level three-phase applications. Moreover, this scheme has also been compared with the standard SHE-PWM scheme through simulation based on harmonics and %THD value up to 40^th order. Here, particle swarm optimization (PSO) technique has been used to find the solution of four variable switching instances and the equally variable DC voltage sources. Finally, simulation and experimental results have been obtained from a three-phase five-level CHB inverter to confirm the aforesaid claims.