Current programmed control of a single phase two-switch buck-boost power factor correction circuit

This paper presents a new current programmed control (CPC) technique for the cascaded two switch buck-boost converter suitable as a low-cost power factor correction (PFC) rectifier in a variable speed motor drive. This new CPC technique, which is an extension of the conventional CPC method, enables variable output DC-voltage and is therefore suitable in a pulse amplitude modulated (PAM) motor drive or as a universal input power supply. The CPC method is very simple and requires only a constant current reference without any changes at the transition between boost and buck operating mode and the line current is practically unaffected by the topology mode shift. The presented control technique is verified by simulations and experimental results and compliance with IEC 61000-3-2 class A is achieved. The experimental setup is based on a commercial CPC IC for DC-DC converters.