A novel adaptive switching method to reduce DC-Link capacitor ripple in PV based grid-connected inverter

In this paper, the developed switching method has been developed to generate trigger signals for the voltage source inverter (VSI) to reduce the current harmonics on the DC-link capacitor. In the novel switching method, at the durations where the DC link capacitor current is greatest, the waveform of the input current of the inverter and the waveform of the output current of the DC side are approximated. The main contribution is to provide a low harmonic content capacitor current with the same capacitor size, thereby increasing the power delivered to the grid. In order to examine the performance of the developed switching method, the spectrum of DC link current obtained by Fast Fourier Transform (FFT) in MATLAB/Simulink. Simulation results have been evaluated according to the value of the harmonic amplitude at the switching frequency. It shows novel switching strategy is more effective in reducing current ripples than the carrier-based Sinusoidal Pulse Width Modulation (SPWM) method which is used as a reference strategy.