基于超级电容的双向DC-DC变换器控制研究

针对轨道交通1 500 V系统再生制动能量利用,研究了基于超级电容储能的输入串联多相并联双向DCDC变换器的控制及其系统能量管理策略。采用输入串联、多支路并联的拓扑结构降低了功率器件电压应力和电流应力及减小了无源滤波器件的体积,同时降低了1 500 V系统对储能元件超级电容的耐压及模组均压控制的要求,使得系统的可靠性更高。针对该拓扑结构的特点,结合工程实际应用,考虑超级电容容值参数差异性及大内阻的特点,以超级电容的能量利用最大化为优化目标,对其充放电过程中超级电容电荷状态误判及系统输入输出侧均压控制策略进行了优化设计。最后通过仿真和实验验证了所提控制策略的有效性。

Research on Control of Bidirectional DC-DC Converter Based on Super Capacitor

Aimed at the regenerative braking energy utilization of a 1 500 V rail transit system, the control of an input series multi-phase parallel bidirectional DC-DC converter based on super capacitor energy storage and its system energy management strategy are studied. The topology structure of input series and multi-branch parallel connection is used to realize the decrease in power device voltage and current stress and to reduce the volume of passive filter devices. At the same time, it reduces the requirements of the 1 500 V system for the withstand voltage of the super capacitor in the energy storage element and the voltage equalization control of modules, so that the reliability of the system is higher. In view of the characteristics of the proposed topology and the practical engineering applications, considering the difference in super capacitor capacitance parameters and the characteristics of large internal resistance, the maximal energy utilization of the super capacitor is taken as the optimization objective, and the misjudgment about the charge state of the super capacitor during charging and discharging and the voltage equalization control strategy on the input and output sides of the system are optimized. Finally, the effectiveness of the proposed control strategy was verified by simulation and experimental results.