A New Single Phase Single Stage High Frequency AC-DC Converter with Complex Programmable Logic Devices (CPLD) Controller

Abstract

A new single phase single stage high frequency AC-DC converter with Complex Programmable Logic Devices (CPLD) controller is presented. The digital controller is developed using CPLD. The proposed system utilizes a single-phase AC input supply. The power switching devices in the controlled bridge are controlled by the multiple-pulse Pulse Width Modulation (PWM) switching technique to minimize the low order harmonics present on the AC side of the converter. A low pass filter is incorporated in the circuit to filter out unwanted harmonics and provide a sinusoidal AC supply current. A high frequency transformer with 1:1 ratio is used in the design to provide galvanic isolation for better circuit performance and protection. The optimum operation of transformer core in four quadrant of B-H curve is also considered in the proposed converter topology. A laboratory prototype of the converter is developed and tested. Experimental results are compared with the simulation results to illustrate the effectiveness of the proposed technique.