Reduction of Common Mode Leakage Current in Three Phase Transformerless Photovoltaic Grid Connected System

The Photovoltaic (PV) based power generation systems are popular nowadays. In this PV based systems the voltage stress across the power devices and leakage current are the major issues in transformer-less grid connected photovoltaic system. To overcome the above drawbacks a Modified T-Source Inverter (MTSI) based single stage transformerless grid connected photovoltaic(PV) system is presented in this paper. MTSI has the advantages of low leakage current, reduced voltage stress, less passive components and no shoot through problem compared to other type transformers grid connected inverter system. The analytical model of leakage current of MTSI based grid connected PV system is derived and simulated using MATLAB Simulink. The simulated results are compared with Improved z-source inverter(IZSI) using modified space vector pulse width modulation scheme(MSVPWM).Finally the performance of MTSI based system experimentally verified; it shows the satisfactory operation in a grid connection mode.

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W artykule opisano zmodyfikowany przekształtnik umożliwiający redukcję prądu upływu w trójfazowym beztransformatorowym układzie fotowoltaicznym podłączonym do sieci. Przedstawiono model analityczny systemu oraz jego symulację. Właściwości układu zbadano tez eksperymentalnie.