Design of 5-level reduced switches count Η-bridge multilevel inverter

Abstract

In comparison with conventional two-level inverter, multilevel inverter provides more than two levels of voltage to achieve high power, smoother and less distorted alternating voltage by using several semiconductor switches and lower level DC voltages as input. Among the available types of multilevel inverter topologies, the H-bridge multilevel inverter requires less number of power switching components, has higher efficiency and has simpler circuit layout. However, it is still limited by switching and conduction losses which mainly occur in main switching devices, and using more than one DC source for more than three voltage levels. To demonstrate an alternative way to reduce the losses without disputing advantageous features of H-bridge inverter, this paper presents a five-level multilevel inverter with reduced switching count, discussing its design features which contribute to less switching losses and Total Harmonic Distortion for motor drives. A computer based model of five levels single phase multilevel inverter was constructed and phase shifted sinusoidal pulse width modulation has been adopted based on 6-kHz switching frequency. The PSIM software environment is used to simulate the results.