Abstract:
Modeling Dual-Active-Bridge (DAB) topologies in a real time simulator presents challenge due to the high switching frequency and the substantial number of submodules. This requires both the firing pulses’ precision and high-speed matrix computation. In this paper, an aggregated model is proposed for a typical Dual-Active-Bridge (DAB) circuit using the state-space circuit approach. It accurately implements the duty cycle of the firing pulses and consequently enhances accuracy. The two H- bridge converters and the ac transformer with the blocking capacitors are consolidated into a single-unit. To address scenarios involving multi-level cascaded DAB units with input series output parallel (ISOP), the multiple single-unit blocks are further packed into an aggregated model. Compared to using single-unit models for the cascaded topology, our developed aggregated model not only conserves electrical nodes, but also the calculation time for history terms, resulting in reduced hardware resources. The simulation timestep can be efficiently reduced, resulting in an outcome of better precise and the capability to model much higher switching frequencies. The proposed aggregated model can be widely applied in the real-time simulation of cascaded DAB topologies, accommodating switching frequency up to 100kHz.
Y. Qi, H. Ding, S. Shi, Y. Zhang and A. Gole, "High Efficiency Modeling of Multi-Layer Cascaded Dual-Active-Bridge (DAB) Units on Real-time Simulator," 2024 IEEE Power & Energy Society General Meeting (PESGM), Seattle, WA, USA, 2024, pp. 1-5
KEYWORDS: Dual-Active-Bridge (DAB), Electromagnetic Transient (EMT), Universal Converter Model (UCM), real-time simulation