Performance of a Dual port Asymmetrical MLI with Solar and Battery using Vertical Shift SPWM

Abstract

In this work, a dual port T-type Asymmetrical multilevel inverter (DP-AMI) is used with two sources namely the PV and the battery is considered. It is assumed that the low voltage level is obtained from battery and high voltage level is obtained from a PV based Boost converter output. Two switches with an antiparallel diode are used to modulate the low voltage level and a conventional VSI is used to obtain a high voltage level in the power circuit. A vertical shifted SPWM is used specifically for this power circuit for obtaining the switching mechanism of the DP-AMI circuit. The analytical study DP-AMI is interfaced between the low level input voltage sources solar and/or battery with the AC load or AC grid. The stepped input solar voltage together with the battery voltage will be converted to an ac source with the help of LC-filter. Using the control mechanism, it is found that the circuit offers improved conversion efficiency compared to the classic H-bridge inverter. It also helps in reducing size of the output filter which is cost effective and also results in less harmonic distortion. The simulation and observation is done for 5 kW load with different power factor’s and also with different modulation indexes.