A Comprehensive Analysis of DC-DC Converters for EV Application by Southern California Edison (SCE)

Electric Vehicles (EVs) are rapidly increasing along with traditional vehicles in the transportation domain. All EV battery chargers require an ac-dc and a dc-dc converter. The prime focus of this paper is on the dc-dc converter, and a pugh chart method is applied to narrow down the selection of current dc-dc converter topologies. Power loss in the semiconductor devices is calculated to evaluate the efficiency of the selected converters. Afterward, a detailed circuit is developed to determine the temperature rise and cost of the converter components. It has been found that the power loss of a flyback converter is 20% less than a push-pull converter; thus, it exhibited a 2% higher efficiency than the push-pull converter. Three of the push-pull converter components exceeded the maximum allowable 90 degrees C temperate, while flyback converter components remained within the limit. The cost is also 16% lower for a flyback converter than the push-pull converter. It has been concluded that a flyback converter would be an optimum choice for the EV battery charger application.