FFT analysis of the composite PWM voltage source inverter

This paper describes a FFT analysis of the composite PWM voltage source inverter (VSI). The VSI has the normal single-phase bridge circuit and an additional arm. The composite PWM method contributes to reduce the ripple in the AC output current. The VSI has a LC series-resonance circuit tuned to twice the utility frequency connected in parallel with the smoothing capacitor Also, the smoothing capacitor is drastically reduced The smooth DC current is obtained by using the resonance circuit tuned to twice the AC source frequency.