An Improved Single Phase Transformerless H5 Inverter with Minimized Leakage Current

This paper, presents an improved single phase transformerless H5 inverter with significantly eliminated leakage current and more effective features where common mode voltage clamping method is used to eliminate the leakage current and super-junction MOSFET are applied to the switches to improve its efficiency. In order to alleviate the AC output current distortion, unipolar PWM technique without any dead time is adopted to the proposed inverter. Around 9.67 mA (RMS) leakage current and 97.78% efficiency have been recorded as optimum performances of the inverter. Moreover, the grid current THD of this enhanced inverter is found 0.68% using conventional LCL filter which is better than existing H5 topology. Hence, the proposed inverter offers superior performances from all aspect over the conventional H5 inverter. The performances of the proposed inverter with theoretical results are verified by simulation carried out in MATLAB/Simulink.