Adaptive Control Technique for High Power Efficiency Dual Active Bridge DC-DC Converter with Wide Load Range

Abstract

Recently, energy network systems with energy storage such as batteries have been focused on using for electric vehicles and power grid systems. Therefore, the Dual Active Bridge (DAB) dc-dc converter has been focused on because it has some unique advantages, such as bi-directional power transmission and high efficiency by Zero-Voltage-Switching (ZVS). However, hard switching and surge current are critical issues at light load. For the improvement of this problem, “masked-switching control (MSC)” was reported previously. However, another hard switching and surge current has confirmed at medium load by MSC. In this paper, the adaptive control method is proposed that can reduce surge current and operate ZVS at medium load. By experimental results, 1.4% of maximum power efficiency improvement at the medium load is confirmed. From the results, it can be seen that the proposed control method can achieve ZVS and realization of high power efficiency with wide load range.