International Journal of Advanced Technology and Engineering Exploration ISSN (Print): 2394-5443    ISSN (Online): 2394-7454 Volume-13 Issue-140 July-2026
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  2. 2.8
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Mitigation of zero-crossing transients in H5 transformerless photovoltaic inverters using RC snubber integration

Aina Suhailah Mohd Azhar1, Maaspaliza Azri1, Wahidah Abd Halim1, Azrita Alias1 and Md Liton Hossain2

Faculty of Electrical Technology and Engineering (FTKE),Universiti Teknikal Malaysia Melaka,Melaka,Malaysia1
Centre for New Energy Transition Research,Federation University Australia, Mt Helen Campus, University,Dr, Mount Helen VIC 3350,Australia2
Corresponding Author : Maaspaliza Azri

Recieved : 12-September-2025; Revised : 14-May-2026; Accepted : 16-May-2026

Abstract

Transformerless photovoltaic (PV) inverters are widely used in residential and commercial applications due to their reduced size, weight, and cost. However, the absence of galvanic isolation introduces leakage current through the parasitic PV-to-ground capacitance (Cp). The H5 topology mitigates this issue by maintaining the common-mode voltage (CMV) at half of the direct current (DC)-link voltage. Nevertheless, transient leakage current spikes still occur at zero-crossing instants due to high dv/dt switching events that excite device and parasitic capacitances. This paper proposes a snubber-integrated H5 inverter in which resistor–capacitor (RC) snubber circuits are incorporated as a hardware-based solution to suppress zero-crossing transients without modifying the original topology or modulation scheme. Experimental results show that both the conventional and modified inverters preserve a three-level output waveform and stable CMV characteristics. However, the inclusion of RC snubbers significantly reduces the root-mean-square (RMS) leakage current from 2.2 mA to 0.91 mA. These results demonstrate that RC snubber integration provides a simple and effective approach for mitigating zero-crossing leakage current while maintaining the inherent advantages of the H5 inverter.

Keywords

Transformerless photovoltaic inverter, H5 inverter topology, Leakage current suppression, RC snubber circuit, Common-mode voltage, Zero-crossing transients.

Cite this article

Azhar ASM, Azri M, Halim WA, Alias A, Hossain ML. Mitigation of zero-crossing transients in H5 transformerless photovoltaic inverters using RC snubber integration. International Journal of Advanced Technology and Engineering Exploration. 2026;13(140):159-169. DOI : 10.19101/IJATEE.2025.121221278

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