Analysis of Different Level Half-Bridge Modular Multilevel Inverter

Abstract

Inverter is a power electronics device which is used to convert DC power to AC power at required output voltage and frequency. It can be broadly classified as two level inverters and multilevel inverters. The multilevel inverters are mainly classified as Diode clamped, Flying capacitor inverter and cascaded multilevel inverter. The design and operation of cascaded half bridge modular multilevel inverter (MMC) was very easy.  Because, no clamping diode and flying capacitor in their structure. The simulation had been carried for single phase three, five and 11 level Half-bridge modular multilevel converter (MMC) by using sub modules. The main objective of this paper is to analyse operation of Half-bridge MMC for different level of voltage by using SPWM (Sinusoidal Pulse width Modulation) technique which reduces total harmonic distortion and enhances output voltage and current closer to sine wave without adding any complexity to the power circuit.

Keywords: Cascaded H-bridge MLI, half- bridge MMC, SPWM techniques, THD