基于燃料电池/电池/超级电容的交通电气化系统混合供电大信号稳定性分析与改进策略

Hybrid power supply systems (HPSSs), which integrate the dynamic properties of different power sources, are a promising solution for transportation electrification systems. However, extreme cases such as large variations of load like large step-changing load and high peak-to-average ratio pulsed power load are highly susceptible to power supply system destabilization, which is beyond the scope of small-signal analysis. In this article, a comprehensive large-signal stability analysis for HPSSs considering variation in virtual impedance droop parameters and proportional and integral (PI) regulators under extreme load switching conditions is conducted based on the region of attraction estimation (ROA). On this basis, the impact of system parameters and load power on the large-signal stability is elaborated. The stability of the system is greatly improved by the adoption of active capacitors to absorb the pulsed power. The effectiveness of the proposed large-signal stability analysis method and the correctness of the analyzing results are verified through experiment results.