The project deals with the reduction of leakage current from Pulse width modulation(PWM). Leakage current reduction is crucial for the transformerless photovoltaic (PV) inverters. The conventional three-phase current source H6 (CH6) inverter suffers from the large leakage current, which restricts its application to transformerless PV systems .In order to overcome the limitations, a new quasi Z- source based three-phase current source H7 (CH7) inverter with is proposed in this paper.Only one additional IGBT is needed, but the leakage current can be effect ively suppressed with a Sine pulse width modulation.  Index Terms-Current source H7(CH7) inverter, current source inverter, leakage current, Pulse Width Modulation (PWM),space vector modulation(SVM)Quasi Z-source inverter.