DC/DC Full-Bridge Converter for Cathodic Protection Application with Phase-Shift Control Method and No Auxiliary Circuit

Cathodic protection (CP) DC/DC converters are the external power sources used in CP applications in which the fix DC voltage converts to variable output DC voltage and bring about variable output current as well. In low to medium output voltages, where the duty cycle is less than 30%, zero voltage switching (ZVS) is unattainable. Therefore, a switching control method which is the combination of ZVS and variable frequency pulse width modulation (VFPWM) is suggested in the article. By using this hybrid control method, the DC/DC full bridge structure operates under an extended range of voltage up to 75V in the output and the output current from 0 to 25A with high efficiency. Simulation results demonstrate the accuracy of this method.