Control Techniques of the Auxiliary-Resonant Commutated Pole With Special Regards on the Dual-Active Bridge DC-DC Converter

Abstract

In this work, a dual-active bridge dc-dc converter with auxiliary-resonant commutated pole is presented. The paper focuses on the control strategies of the auxiliary-resonant commutated pole to allow soft turn on and soft turn off of the main switches, and thus increasing the efficiency of the converter. These strategies are developed for a high-power IGCT-based dual-active bridge dc-dc converter. Two boosting strategies, constant time magnetization and constant current boosting are presented and tested. Besides its main objective to reduce the switching losses, the ARCP also allows balancing of the dc-link voltages in case of imbalanced loads. Strategies for boost current control and active dc-link balancing are introduced, presented and experimentally verified on a small-scale laboratory setup.Index terms-DC-DC power converters, field programmable gate arrays, resonant inverters, soft-switching, zero-voltage switching. I. IntroductIon And motIvAtIonI N Fig. 1, the schematic of a dual-active bridge (DAB) dc-dc converter with auxiliary-resonant commutated pole (ARCP) is shown. In case one of the main devices is switched, the ARCP causes a resonance to allow a zero-voltage condition at the main devices which then results in soft switching. This soft-switching behavior can be supported by additional resonant capacitors C res . In case of using ARCP with IGCTs, it has been shown that the switching losses can be reduced to an eighth of the original amount [7]. Further details on the DAB can be found in [1] and [8] and on the ARCP in [2] and [9]. The presented control techniques for the ARCP are developed for a 5 MW DAB. Therefore, some presented hardware components are designed for 5 kV and fiber optical logic signals are used. The techniques are tested on a smallscale model (SS-DAB) rated for powers in the lower kW range to minimize risks.

A zero‐current‐transition soft‐switching technique for T‐type NPC three‐level inverter

“…Auxiliary resonant commutated pole (ARCP) is a typical topology of ZVT soft-switching [6,7]. The auxiliary resonant circuit includes auxiliary power switches, resonant inductors and resonant capacitors.…”