Analysis and design of single stage dc dc sepic converter based power factor corrector using conventional and soft computing techniques

Abstract

Most of the electronic equipments used in industries and commercial applications are powered by utility supply and the power supply requirement is processed with the application of power converters. Due to an intensive need of power converters and also the use of non-linear loads by industry and consumers, a great care has to be taken to meet the standards in supplying good quality power. Specifically the presence of power electronic converters as an interfacing unit between the front end of DC-link power converters and AC line is more common in all sort of electronic appliances. But these components are generally found to be nonlinear in nature and consequently lead to generation of harmonic currents in the AC line power. This results in poor power factor, high percentage Total Harmonic Distortion (THD), decreased efficiency and poor voltage regulation. To address the aforementioned issues, active and passive Power Factor Correction (PFC) techniques are employed. Due to some limitations like bulkier components and high cost associated with passive PFC technique, active PFC using DCDC Single Ended Primary Inductance converter (SEPIC) has been proposed in this work. PFC circuit employed for shaping the input current is emulated as a resistor on the input side while maintaining a regulated voltage at the output side. For a sinusoidal line voltage, it is therefore necessary to generate newlinesinusoidal reference current which must be followed by the line current by the application of active PFC. Two approaches namely voltage mode control and current mode control have been used for the generation of PWM signal in PFC. To overcome few operating limitations of voltage mode control such as i) Less stability of feedback loop ii) Slow response to load transients, current mode control is preferred in this work for PFC. It is a modified voltage mode control, where it uses two loops to control the output voltage and correct the newlinePF of the source current effectively. newline newline