Performance comparison between optimization algorithms for asymmetrical cascaded multilevel inverter control

Abstract

This paper discusses the hardware and control system design of the asymmetric cascade multilevel inverter. The asymmetric cascaded multilevel inverter structure is adopted to minimize bridges, gate drive circuits and DC power source number. Therefore, the proposed structure is able to generate higher voltage at higher speed with low switching losses and high efficiency. Selective Harmonic Elimination (SHE) based on Newton-Raphson (N-R) algorithm is developed to calculate a switching angle for a range of modulation index to control asymmetric cascade multilevel inverter. Simulation results prove that Newton-Raphson technique is more effective than genetic algorithm (G-A) and equal calculated switching angles method (ECSA). A comparison between the algorithm performance for 9-level asymmetric cascade H-bridge inverter control was evaluated and experimentally tested on FPGA-based prototypes