Leakage Current Mitigation in Transformer-less Photovoltaic Inverter Systems for Mining Equipment

Challenging task of leakage current in photovoltaic converter is dealt for the application of portable mining electrical equipment. Inductive load and earth leakage causes distortion in the performance of the equipment in the transformer-less photovoltaic inverter systems. This leakage current introduce electromagnetic interference with neighboring circuits. The basic six device B6 type voltage source inverter is widely used for photovoltaic inverter systems, but leakage current is not addressed. H7 and H8 with additional switching device topologies reduces the leakage current problem and control strategy detects zero voltage states for reduction in switching losses. The proposed concept minimizes the leakage current due to inductance of RL loads, in general and specifically for mining equipment. Simulations study was carried out using MATLAB simulation software. Experimental were also carried out in real time, results showed that, reduced leakage current and total harmonic distortion in the output voltage and current waveforms. The elimination of the transformer and loading effects were analyzed for mining equipment having 1 kW Photovoltaic inverter system.