Transformerless DC–AC Inverter With Low Switch Count and Low Leakage Current

ABSTRACT This paper presents a novel transformerless, common‐grounded, grid‐connected inverter for photovoltaic (PV) systems. The proposed architecture integrates a single‐switch bipolar boost converter in the direct current (DC)–DC stage and a half‐bridge inverter for the DC–alternating current (AC) conversion. The main features include the use of a single active switch in the DC–DC stage, nonpulsating input current, and grounded bipolar DC bus, which effectively mitigates common‐mode leakage current. This configuration results in a simple and low‐complexity system suitable for applications in PV systems. To validate the theoretical analysis and performance of the proposed inverter, an experimental prototype with a nominal power of 1.5 kW, input voltage of 136 , DC bus of 800 , and output voltage of 220 was developed. The experimental results confirm the expected performance, with a maximum leakage current of only 0.117 mA and peak efficiency of 96.26% operating at 750 W.