Single-phase, wide line voltage range, buck power factor corrector with lower harmonic contents in compliance with IEC standard 61000-3-2

This paper focuses on a new single-phase AC-DC buck converter which has ability to operate with wide line voltage range at near unity power factor. This converter is composed of two controllable power switches and fast switching diodes. This converter is operated at constant switching frequency with variable duty cycle, using a very simple control scheme in voltage follower mode. Neither an analog multiplier nor an input voltage sensor is needed to achieve sinusoidal line current waveform. The control strategy uses only sensing of output voltage and it also eliminates the sensing of line current. The output voltage is kept constant irrespective of variations in the line voltage. The converter is simulated along with control scheme to check the validity. It has been observed that, the line current drawn by the converter is almost sinusoidal and follows the line voltage. The line current harmonics are within the class A and class D limits imposed by international standard IEC 61000-3-2. This converter has potential applications in battery charging. A laboratory prototype is built and tested to verify the proposed converter.