Novel Hybrid Neutral Point Clamped Inverter for Single-Phase Grid-Tied Transformerless Inverter

Abstract

The Grid-Tied inverter is one of the fast-evolving technology in the present era that aims to support the centralized power generation system with a distributed power generation system. The use of renewable energy resources makes it popular due to its ease of availability. The issues associated with Grid-Tied inverter are its size and cost. To reduce the size and cost of the inverter in grid-tied inverter it is required to replace the conventional inverter with a transformerless inverter that leads to leakage current generation between the grid and Photovoltaic Cell. This paper presents a discussion on the neutral point clamped inverter used in the Grid-Tied inverter system that aims to reduce the leakage current. This paper presents a novel hybrid neutral point clamped inverter topology for single-phase Grid–Tied inverter to reduce the leakage current by providing an additional freewheeling path. It is observed that the proposed topology ensures good common mode characteristics by keeping the leakage current to 8mA RMS, keeps the common-mode voltage constant, a current THD of 0.19% and an efficiency of 96.41% is achieved. The results are compared with existing topologies.