Single-Phase Transformerless Dual Buck-Based Grid-Connected Inverter

This work proposes a novel single-phase transformerless dual buck-based grid-connected inverter. The proposal features only two power semiconductors in the current path at all operating stages and, thus, enables low conduction losses. The topology guarantees increased robustness since the dc-bus cannot be short-circuited by a shoot-through event. Since the inverter uses two inductors the use of coupled inductors is proposed to reduce the overall passive components volume and better use of the magnetic cores. Experimental results of a 2 kW prototype (+380 V to 220 V /60 Hz) are presented, which show that the proposed inverter is able to achieve high efficiency (> 98%) and low common-mode voltage when switching at 50 kHz.