Power factor correction method and device

Abstract

A power factor correction method and the controller thereof, applied to a boost-type converter, are provided. First, the power factor correction method uses the input and output voltages to generate a reference switching signal. Next, a voltage control circuit uses the difference between the output voltage and a voltage command to get a duty phase. Then, the switching control signal is determined by shifting the phase of the reference switching signal according to the duty phase. Finally, a comparator compares the switching control signal with a triangle waveform signal to determine the switching signal. A power factor controller, which utilizes this method, uses only a single voltage control circuit to get the switching signal to regulate the output voltage and shape the current waveform without sensing current and a current control circuit, so that the complexity of the invented control circuit for the power factor correction is reduced dramatically.