Novel High Efficiency H-Bridge Transformerless Inverter for Grid-Connected Single-Phase Photovoltaic Systems

Abstract

This paper proposes a new H-bridge type transformerless inverter for grid-connected photovoltaic (PV) application. The proposed H-bridge zero voltage switch controlled rectifier (HB-ZVSCR) inverter uses additional switches and diodes at the AC side with voltage clamping feature to the DC midpoint. Main characteristics of the proposed inverter are the high conversion efficiency and low leakage current, which make it a suitable candidate for grid-connected PV applications. The analysis and operating principles of the proposed inverter are discussed in details. This theoretical findings has been simulated using PLECS software to verify the common mode voltage (CMV) and leakage current behaviors and the results are compared with similar existing midpoint voltage clamping inverter topologies (i.e. HB-ZVR and HB-ZVR-D). Furthermore, power loss and efficiency of the proposed inverter have been evaluated and compared with existing topologies.

A novel five-level switched capacitor type inverter topology for grid-tied photovoltaic application

“…Therefore, many topologies have been proposed to focus on single source with less required semiconductor devices and overcome this pressing issue [8]- [9]. Topologies with common-ground terminal significantly reduce the number of power devices, whilst nullifying the leakage current to the grid [2], [10]. Similarly, multilevel converters, which clamp the common mode voltage (CMV) during the freewheeling period, have received more attention in the recent time for medium power PV applications as they adopt the concept of common ground for effective elimination of leakage current.…”