Performance comparison between HERIC and Z-source single-phase transformerless inverters

Nowadays, transformerless photovoltaic (PV) inverter systems are becoming to be used widely to achieve high efficiency, and the research level of PV systems is widespread continuously. However, main problems of PV inverter systems are the leakage currents, electromagnetic emissions, and losses in system. This paper introduces the buck-boost-based three-switch three-state Z-source inverter for using with grid-connected PV system, and it can provide dual grounding for suppression problems of PV inverter system and provide boost capability. Moreover, this paper presents the performance comparison between the buck-boost-based three-switch three-state Z-source grid-connected PV inverter and highly efficient and reliable inverter concept (HERIC) grid-connected PV inverter with boost converter. The detailed designs are validated by the simulation results.