Amended THD with modified phase-shifted PWM for micro-grid connected multilevel inverter

In this work, the phase shifted carrier pulse width modulation (PSC PWM) technique is applied as the most favorable modulation scheme for a photovoltaic (PV) fed cascaded multilevel-micro-grid connected inverter (CM-MGCI), with consideration of the total harmonic distortion (THD) of the output voltage. In addition to this, a modified PSC PWM method named as variable amplitude PSC-PWM (VA-PSC-PWM) is proposed. To verify the performance of proposed PSC PWM method, MATLAB/Simulink simulations are performed with nine-level CM-MGCI. To feed the CM-MGCI required voltage, a PV array is designed and a maximum power point tracking (MPPT) technique is demonstrated in MATLAB/Simulink environment. From the voltage profile of VA-PSC-PWM technique, it is observed that the proposed method gives better THD profile than classical PSC PWM method. Our proposed modified PSC-PWM also provides better THD profile compared to other recently proposed PSC-PWM technique.