PFC Interleaved Buck-Boost Converter for Telecom Power Application

At present, the field of power factor corrected (PFC) rectifiers are very much matured. Typically a single phase PFC converter requires measurements from three independent sensors i.e. input voltage, input current and output voltage. By considering a need of farther compact and more flexible in terms of input to output voltage gain, a new UPF rectifier with two buck-boost converter operating in interleaved condition with use of only one output voltage sensor is presented. The proposed control technique uses only integrator to compensate the error between measured voltage and reference voltage and it is very simple to implement. The proposed Buck-boost converter operates in Discontinuous Conduction Mode (DCM) to achieve UPF at AC input. The required buck-boost inductance in DCM operation is quite small. In contrast to this, the current ripple of buck-boost inductor is quite high. Interleaving is the viable option to reduce the inductor current ripple, component stress, input filter size and enhances the power density. To verify the feasibility of the proposed scheme, the proposed converter is repeatedly simulated in PSIM and in real time platform OP4510. A scaled down lab prototype is built and experimental results are presented to verify the suitability of the proposed converter for the practical application.