减缓配电网冲击的超级电容储能站充电技术

Charging Technology of Supercapacitor Storage Station for Mitigating Power Impact on Distribution Network

基于超级电容预储能的城市公交电车充电站可以有效减缓充电站对配电网的冲击。对充电站的超级电容组充电策略进行研究,提出了适用于不同容量和SOC(荷电状态)、特别是在不平衡电网条件下的充电策略。为实现对三相四线制PWM(脉冲宽度调制)整流装置在不平衡电网下输出电压二倍频的抑制及单位功率因数控制,研究了正负序电流解耦控制算法;为保证PWM整流装置输出电容电压均衡,研究了电容电压均衡控制策略;为实现不同负载下超级电容组充电电流的连续性,研究了三电平DC/DC变换器电流闭环控制策略,提出基于超级电容组SOC的充电策略。通过Simulink仿真,验证了超级电容组充电策略的正确性和有效性。

The urban bus charging station based on supercapacitor pre-storage technology can effectively mitigate the power impact of charging station on the distribution network. The charging strategy of supercapacitor bank in the charging station is studied, and a charging strategy under different capacities, SOC(state of charge) and especially under unbalanced power grid is realized. In order to realize the frequency doubling output voltage suppression which is caused by positive and negative sequence components in unbalanced power grid and unit power factor rectifier of the three-phase four-wire PWM rectifier under unbalanced power grid, the decoupling control algorithm of positive and negative sequence current is studied;in order to ensure continuity of charging current of supercapacitor under different loads, the closed-loop current control strategy of the three-level DC/DC converter is studied, and a charging strategy based on SOC of supercapacitor bank is proposed. The correctness and effectiveness of the charging strategy is verified by Simulink simulation.