A Low Complexity Algorithm for Efficiency Optimization of Dual Active Bridge Converters

Abstract

This paper proposes a triple phase shift modulation (TPS) with an optimization technique that aims at maximizing the efficiency of the dual active bridge converter. Such a converter is often used to interface renewable or energy storage systems in smart dc power systems, where loss minimization via TPS is crucial, especially at light-load conditions. In this paper, favorable modulation parameters are found first, aiming at minimum rms currents and zero voltage switching, by considering only some fundamental converter parameters, namely, the input and output voltages, the transformer ratio, and the leakage inductance. Then, on the basis of the closed-form analytical description of the converter behavior over the determined modulation patterns, trajectories in the modulation planes that are capable of improving the total efficiency are identified. It is shown that such trajectories lead to close-to-optimal efficiency operation, which can be exploited to implement fast perturb-and-observe methods requiring just minimal converter parameters knowledge. The results are verified experimentally on a 1.5-kW prototype. It is shown that the proposed approach achieves close-to-optimal efficiency operation under different input voltages, being the error with respect to the measured optimal points obtained by a brute-force approach lower than about 0.2%. Index Terms-Dual active bridge (DAB), light-load operation, maximum efficiency point identification, TPS optimization, zero voltage switching (ZVS).

An Optimal Control Strategy for the DAB-Based Partial Power Converter Based on Extended-Phase-Shift Control

“…Extended-Phase-Shift Control performance [19]- [20], and minimizing root-mean-square (RMS) current [21]- [22]. Under the condition of high frequency, the effects of the output capacitors of switches can be amplified because the charging and discharging process of output capacitors are hard to be ignored due to short switching period.…”

Design and Implementation of a Two-Stage Resonant Converter for Wide Output Range Operation

“…7c, red lines highlight those points where ZVS is achieved for all the switches with minimum inductor rms current, which relates to the minimum phase-shift values to achieve ZVS. Such an inductor current computed as in (7) is shown in Fig. 7b and Fig.…”

“…Among these, the dual-active-bridge (DAB) and the resonant LLC converter are often considered for their several merits [2], [6]. The DAB converter offers straight-forward voltage regulation and its voltage step-up/down capability is convenient in many applications, such as for the connection of renewable sources to dc distribution busses operating at different voltage levels in stationary microgrids [7] as well as for battery chargers This work has been created in the context of the PROGRESSUS project. This project has received funding from the Electronic Components and Systems for European Leadership Joint Undertaking under grant agreement No 876868.…”

Design Space Analysis of the Dual-Active-Bridge Converter for More Electric Aircraft

“…The analysis of the design space has been widely utilized in the literature to optimize the power density of magnetic components, such as inductors [23] and/or power transformers [24], improving the resulting efficiency of these components. Moreover, many optimization routines are found for DAB based topologies in different applications [25,26].…”