基于模块化多电平换流器的超级电容储能系统高效仿真方法

Efficient simulation method for modular multilevel converter with embedded super capacitor energy storage system

基于模块化多电平换流器的超级电容储能系统(MMC-SCES)半导体开关器件数量众多,仿真规模庞大,给电磁暂态仿真效率带来了巨大的挑战。针对此问题,基于桥臂戴维南等效电路提出了一种高效的MMC-SCES电磁暂态仿真方法。该仿真运用嵌套快速求解方法对MMC-SCES进行建模,不仅可以大幅降低仿真耗时和保持仿真精度,还可以保留换流器的所有动态变量。搭建了双端MMC-SCES仿真系统,对所提出的高效仿真方法进行了验证。结果表明:相比于基于平均值模型的仿真方法,所提出的高效仿真方法具有更高的精度,能够拟合子模块内部动态变量;相比基于详细开关模型的仿真方法,所提出的高效仿真方法的仿真速度最高可提升约518倍,而仿真的绝对误差标幺化积分则控制在1%以内。

There are a large number of semiconductor switching devices in the modular multilevel converter with embedded super capacitor energy storage system(MMC-SCES),and the simulation scale of MMC-SCES pose a huge challenge to the efficiency of electromagnetic transient simulation.To overcome this issue,it is proposed an efficient MMC-SCES electromagnetic transient simulation method by constructing the Thevenin equivalent circuit of the bridge arm.This method significantly reduces simulation time and maintains simulation accuracy while preserving all dynamic variables of the converter.A dual-ending MMC-SCES simulation system is built in PSCAD/EMTDC to validate the proposed efficient simulation method.The results show that compared with the simulation methods based on the average value model,the proposed efficient simulation method has higher accuracy and can fit the dynamic variables inside the submodules,compared with the simulation methods based on detailed switching model,the proposed efficient simulation method can increase the simulation speed by about 518 times,while the normalized integral of absolute error is controlled within 1%.