Transformerless Single Phase Inverter Suitable for Grid Connected Application

Abstract

In Photovoltaic generation system Transformerless inverter has attracted more attention because of its high efficiency output and reduced cost. The transformerless inverter used for grid connected application in which leakage current is one of the main issues this leakage current has to be tackled properly to avoid EMI problem. Hence, the main aim of this paper is how to achieve common mode voltage constant to eliminate the leakage current. This is done by applying any one of the following SPWM strategy it can be: 1. Basic SPWM strategy 2. Bidirectional SPWM control strategy, Thus by applying any one of the strategy mentioned above the leakage current can be reduced by keeping common mode voltage constant, hence by achieving common mode voltage constant high reliability is obtained. By eliminating the dead time effect, low total harmonic distortion is reduced. Because of using three level output voltage the output filter inductance size is reduced this will lead to high efficiency and power density.