IEEE Transactions on Power Electronics | 2021
Variable Output Voltage Switching Rectifier for Cathodic Protection Applications With DC–DC Variable Frequency and Duty-Cycle Full-Bridge Converter
Abstract
Rectifiers used in cathodic protection (CP) applications convert ac voltage to variable dc output. This article proposes a switching converter for CP, mostly to enhance the efficiency in low to medium output powers, where the duty cycle is less than 30%. This device is composed of two parts, an ac–dc converter and a dc–dc full-bridge converter. The ac–dc converter is a single-phase boost-type power factor correction converter with emphasis on high efficiency, thus resulting in an almost unity power factor and fixed dc output voltage. The dc–dc full-bridge converter operates under pulsewidth modulation with the simultaneous change of frequency and duty-cycle (SCFD) control method responding to the user output power demand. The SCFD control strategy, in this converter, increases overall efficiency of the proposed rectifier. Finally, a 1875\xa0W prototype is implemented and tested to verify the nearly fixed high efficiency for the converter in a wide operating range of the output power.