An Improved Charge-Based Method Extended to Estimating Appropriate Dead Time for Zero-Voltage-Switching Analysis in Dual-Active-Bridge Converter

Abstract

This paper presents a comprehensive analysis of zero-voltage-switching (ZVS) realization with an improved charge-based method by considering both voltage dependency parasitic capacitance and dead time in dual-active-bridge (DAB) converters, when the voltage ratio between the primary and secondary sides does not match the turn ratio of the transformer. For this purpose, a unified equivalent circuit is proposed to represent the switching motions at all possible switching instances under the condition of one-leg manipulation. The combinations of switching cases can be presented in a table to build the corresponding equivalent circuit for ZVS analysis. Combined with the improved charge-based method, the common solutions of the minimum required switching current and the appropriate dead-time range for each equivalent circuit to realize ZVS are deduced. The allowable range of the dead time for ZVS as a function of the switching current is analyzed to determine the appropriate dead time. Once the switching current and dead-time range are derived, the model-based lowest switching current control method can be used to achieve ZVS by using the appropriate amount of both factors. Experiments using a 4 kW DAB prototype were conducted to verify the theoretical analyses.

Analysis of dual active bridge-based on-board battery charger for electric and hybrid vehicles

“…The method is easy to implement and shows excellent control performance, but the overall efficiency is not sufficient. The square voltages in a circuit that is modulated with this scheme will always have duty cycles of 50% of the switching period while the frequency stays constant [23]. Two square voltages 𝑉 𝑇1 and 𝑛𝑉 𝑇2 are generated on the primary and secondary side of the transformer by giving respective switching signals to the switches Q1 to Q8.…”

A Backflow Power Suppression Strategy for Dual Active Bridge Converter Based on Improved Lagrange Method

“…The DAB converter is commonly operated using phase-shift modulation [10], which can be further categorized into single-phase-shift (SPS) modulation [11], extended-phaseshift (EPS) modulation [12], dual-phase-shift (DPS) modulation [13], and triple-phase-shift (TPS) modulation [14]. SPS modulation is the easiest to implement, as it only requires a single control variable between bridges.…”