A fuzzy controller for extending linearity of overmodulated PWM waveform

A fuzzy controller for generation of pulse width modulated gating signals for a single phase converter is developed. The fuzzy controller is used to establish feasibility of overmodulation with less distortion and an extended range of linear control of output voltage. The sinusoidal pulse width modulation waveform required for switching functions of an inverter has a linear range upto the modulating index of 1.0. An increased distortion is the result of overmodulation. In this paper, using a feedforward cascaded fuzzy controller, the fundamental component of output waveform is increased upto 1.135 p.u. linearly, without appreciably enhancing distortion. The implementation is confirmed through results.