Investigation on pfc sepic converter based coupled Inductor system

Abstract

The switches in the converters need to operate at a very high frequency, it is forced to inject harmonics to the system which leads to reduction in the efficiency of the converter and increase in the power intake which leads to stress in the switches and reduction in the life of the operation of the switches, hence improvement of power factor is very vital to increase the power transfer capability of the power converter. Several converters are available for the Power factor control methods like boost converter, buck-boost converter, CUK Converter and SEPIC Converter. The main motivation is to develop a simple DC-DC Converter topology with low switch count, low cost, high gain and efficiency with power factor correction. A sepic is essentially a boost converter followed by an inverted buck-boost converter therefore it is similar to a Conventional buck boost converter but having the advantages of non-inverted output using a series capacitor to transfer the energy from input to output. The output of sepic is controlled by duty cycle. newlineThis thesis proposes the analytical modeling and controlling of modified bridgeless sepic converter topology for power factor correction. An auxiliary switch, coupled inductor, clamp capacitor and a feedback controller designed additionally compared to conventional Sepic converter. The contribution of the proposed converter topology is ripple free input current, enhanced voltage gain and efficiency. The steady state and dynamic performance of the proposed converter topology is verified in the MATLAB/Simulink environment. The power factor improvement of AC side envisaged through a SEPIC converter with zero voltage transition utilising a bidirectional switch and fast diodes are presented newline