• Smitha Joseph

This paper presents a comprehensive review of H-Bridge, H5, and H6 inverter topologies for transformerless grid-connected photovoltaic (PV) systems. Transformerless inverters have gained significant attention due to their higher efficiency, reduced size, lower cost, and improved power density compared to transformer-based counterparts. However, the absence of galvanic isolation introduces challenges related to common-mode voltage (CMV) fluctuations and leakage currents, which pose safety hazards and can affect system performance. This review systematically analyzes and compares the H4 (conventional full-bridge), H5, and H6 topologies in terms of efficiency, leakage current suppression, total harmonic distortion (THD), component count, and control complexity. The paper also discusses various modulation strategies, safety standards compliance (VDE 0126-1-1, IEEE 1547), and the impact of wide-bandgap semiconductor devices on inverter performance. Research gaps and future directions, including AI-based optimization and wide-bandgap integration, are identified to guide future research efforts in this domain.

Transformerless inverter, H5 topology, H6 topology, common-mode voltage, leakage current, photovoltaic systems, grid-connected inverter

"Performance Comparison of H-Bridge, H5, and H6 Inverter Topologies for Transformerless Grid-Connected Photovoltaic Systems: A Comprehensive Review", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.13, Issue 1, page no.g895-g904, January-2026, Available :http://www.jetir.org/papers/JETIR2411697.pdf

"Performance Comparison of H-Bridge, H5, and H6 Inverter Topologies for Transformerless Grid-Connected Photovoltaic Systems: A Comprehensive Review", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.13, Issue 1, page no. ppg895-g904, January-2026, Available at : http://www.jetir.org/papers/JETIR2411697.pdf