Trapezoidal Inverted Sine PWM Techniques for Fundamental Fortification in PV Fed Multilevel Inverters

Renewable energy sources, especially solar photovoltaic systems (PV) are gaining popularity as the demand for electrical energy is increasing day by day. They can act as a voltage source feeding the power circuit. This work aims in utilising the PV system as a voltage source for a cascaded five level inverter. Further the performance of the PV panel fed cascaded multilevel inverter is analysed by applying trapezoidal inverted sine PWM schemes. Many pulse width modulation (PWM) techniques were proposed and reported in literature with the aim of reducing the total harmonic distortion and enhancing the fundamental output voltage. Trapezoidal PWM scheme is one such scheme which is found to enhance the fundamental output voltage than the commonly used sine PWM scheme. This paper proposes a new PWM technique where gating pulses are produced by comparing a trapezoidal reference with multiple high frequency inverted sine carriers. Perturb and Observe (P&O) maximum power point tracking (MPPT) algorithm is used to extract the maximum power form PV panel. Keywords— PV, MPPT, P&O, PWM, TISC PWM, TTC PWM, MLI,THD