Closed loop cuk topology based single phase high performance AC-DC converter

Abstract

Single phase rectifiers are commonly used in low and medium power application due to their low cost and ease of control. Rectifiers are non-linear in nature and draw non sinusoidal input current from the AC power sources. This causes a number of problems in sensitive electronics equipments and in the power distribution networks. Moreover it increases in reactive power drawn and reduce the input power factor. To reduce these problems switch mode regulated rectifiers are used. This thesis focuses on the study and digital implementation of a power factor correction (PFC) converter using close loop Ĉuk topology. This thesis work controls output voltage of a rectifier by inner current control based power factor correction (PFC). It provides high efficiency (more than 80%), less input current THD, nearly unity power factor and better output voltage regulation of AC-DC converter under variable input voltage, frequency and output load. Small signal model analysis is carried out through state space averaging technique and mathematical expression is developed for obtaining frequency response and checking the stability of the system. An algorithm is developed for digital implementation of proportional integral control. It presents a customized simulink model to represent the whole system and then an algorithm for digital implementation is developed. It also shows the real time simulation of simulink model through voltage sensor, current sensor and Digital signal controller. Finally real time C and assembly code for programming the Digital signal controller is presented.