Diode-rectifier clamped half-bridge single-phase optimized transformerless inverter Conference Paper uri icon

abstract

  • This paper discusses the proposal of a single-phase inverter to deal with the leakage ground current problem in transformerless photovoltaic systems. The high efficiency and low cost allow non-isolated inverters to widespread their applications in the grid connected photovoltaic energy market. The removal of the low or high frequency transformer in a photovoltaic system let a ground path for the circulating leakage current produced by voltage variations in the stray capacitance formed between the photovoltaic panel surface and its grounded frame. To deal with this issue, a single-phase inverter and its modulation strategy is discussed in this paper. The topology is based in the conventional single-phase half-bridge inverter plus a single-phase full-bridge rectifier connected to a single switch. A conventional sinusoidal based pulse with modulation is proposed to improve the topology performance regarding leakage current. Finally, silicon carbide diodes are used in the diode bridge to significantly improve the overall inverter efficiency. Numerical results show that the proposed PV inverter modulated with the proposed modulation strategy complies with the transformerless norms and regulations and operates with high efficiency, being this suitable for applications of grid-connected transformerless PV energy generators. © 2016 IEEE.

publication date

  • 2016-01-01