Work

Impact of Switching Timing on Voltage Rise and Output Ripple in GaN-Based High-Frequency DAB Converters

Year: 2026

Type: article

Abstract: High-frequency operation enabled by GaN power devices is a promising approach for achieving high power density in dual-active-bridge DC-DC converters. However, as the switching frequency increases, the influence of switching timing parameters on voltage quality becomes critical. While abnormal voltage plateau phenomena have been observed in various DAB platforms, a systematic analysis specifically addressing this phenomenon in GaN-based DAB converters has not been clearly reported. This paper identifies and characterizes a distinct abnormal voltage plateau at the transformer windings in a high-frequency GaN DAB converter, distinguished from conventional transient overshoot. The formation mechanism is clarified: incomplete current commutation within the dead-time interval, combined with phase-shift mismatch between the two bridges, excites parasitic LC resonance that sustains the voltage at an abnormal level. Experimental results on a 100 kHz/1 kW GaN DAB prototype demonstrate that reducing dead time from 400 ns to 50 ns suppresses the abnormal voltage plateau from +75 V to negligible levels and reduces output voltage AC ripple from 2.1 V to 0.5 V. Furthermore, it is shown that the triple-phase-shift control strategy combined with optimized dead-time selection effectively suppresses the formation conditions of the abnormal voltage plateau, as verified by experiments. Compared to single-phase-shift control, TPS achieves superior suppression by actively scheduling current commutation within the dead-time window. These findings establish a quantitative relationship between switching timing parameters and voltage quality in high-frequency GaN DAB converters, providing a foundation for optimized modulation design.

Source: World Electric Vehicle Journal

DOI: 10.3390/wevj17100515

Authors: Yipu Xu, Yuli Lv, Zhonglin Liu, Chaoyang Zhang, Chengsong Li

Institution: Yibin University

Language: English

Topic: Advanced DC-DC Converters

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,689

Funder: Yibin University