A new APWM technique with harmonics elimination and power factor control in AC choppers

A novel asymmetrical pulsewidth modulated (APWM) control technique for AC choppers is proposed which can improve the input power factor and eliminate the harmonics of output voltage up to a specified order, and also enables linear control of the fundamental component of the output voltage. The PWM switching patterns at the specified phase angle are obtained by the Newton-Raphson method. By digital simulation several characteristics for an AC power circuit with the proposed AC chopper are investigated theoretically, and then compared with those of the conventional PWM and APWM techniques.<<ETX>>

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