Design and Implementation of Isolated 30 V, 500 A DC Power Supply using Synchronous Rectifier

Abstract

With advances in modern power electronics, low-voltage high-current DC power supply is used extensively in industrial applications like arc furnace, fusion technology, arc welding etc. Conventional techniques have many limitations like lower efficiency, higher weight and size. The main aim of this project is to meet design requirements for many industrial applications like isolation between source and load, minimize the switching loss, high conversion efficiency, lower output voltage and current ripple and compact the power supply in nature. Phase shifted full-bridge topology is best suited over other topologies for the high power applications. PWM (Pulse Width Modulation) technique along with ZVS (Zero Voltage Switching)/ZCS (Zero Current Switching) is selected to reduce switching losses and to improve the performance of the power supply. In low-voltage applications, conduction loss of the diode bridge rectifier contributes significant power losses in the power supply. So to overcome this limitation synchronous rectifier topology is adopted. Feed forward technique has been adapted to minimize the output ripple from the DC link. Simulation can be done in PSIM software to validate the performance of power supply with isolated phase shifted full bridge topology with synchronous rectifier. Hardware prototypes of 900 W, 6 kW, 15 kW open loop isolated DC power supply built with ferrite core were practically tested. The results were found acceptable.