A Novel Transformerless Single-Phase Three-Level Photovoltaic Inverter

摘要

Single-phase transformerless inverter is widely used in low-power photovoltaic (PV) grid-connected systems due to its small size, high efficiency and low cost. This paper proposes a novel high efficiency transformerless single-phase three-level-based photovoltaic inverter. The topology is simulated and experimentally validated in a 1.2-kW prototype and a comparison with three-level diode clamped inverter is performed. The results show that the proposed topology retains the positive characteristics of the three-level diode clamped inverter; namely, the nongeneration of variable total common-mode voltage, the reduced current ripple, and the high efficiency. The advantage of the proposed topology is that it reduces the input voltage by half compared with the three-level diode clamped inverter.