Controller Circuitry Design for a Voltage Dropping Type Power Factor Corrector

This research focuses on the development of a controller circuitry for a voltage dropping type power factor corrector. The circuit is designed to control a voltage dropping converter, enabling it to effectively perform power factor correction. By employing an inductance current critical intermittent control technique, the on-time of a switching tube in a Buck circuit is modulated to align with the power frequency period and the increase in input voltage. Furthermore, the critical intermittent working mode of inductance current is controlled, allowing for resonance between the junction capacitance of the switching tube and the inductance when the inductance current is greater than zero. The switching tube is then connected when the voltage resonance of the junction capacitance reaches the volley bottom. The proposed controller circuitry offers the following characteristics: high power factors throughout the entire input voltage range, compliance with the harmonic requirements of IEC 61000-3-2 Class C and Class D, and high overall efficiency.