In photovoltaic (PV) grid-connected energy conversion systems with no galvanic isolation, PV module parasitic capacitance introduces ground leakage current (common mode current (CMC)) which its amplitude depends on converter topology and pulsewidth modulation (PWM) technique. This paper analyzes and comparisons the performance characteristic of conventional PWM method, space vector PWM (SVPWM) and reduced common mode voltage (RCMV) PWM methods, AZSPWM, NSPWM and RSPWM. The number of switching per periods, voltage linearity, CMC, CMV, harmonic distortion factor (HDF), DC-Link ripple current of each modulation methods are thoroughly investigated by analytical methods and computer simulation. The main objective of this paper is to investigate optimal RCMV PWM methods with considering deadtime effect. This paper aids design engineer in selection of RCMV methods with respect to their applications.

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