ASYMETRICALLY PULSE-WIDTH MODULATED AC CHOPPERS

An asymmetrical PWM control technique is proposed which can improve the input power factor of ac chopper and also suppress its harmonic contents of currents at both its input and load sides. The ideal switching function for the proposed technique is derived and hence converted into asymmetrical PWM pattern for practical implementation of ac voltage regulator. The theoretical characteristics of the proposed PWM technique are investigated by digital simulation and also compared with those of the conventional PWM one.