基于超导磁储能系统的微电网频率暂态稳定控制策略

微电网作为智能电网的重要组成部分,具有并网运行和孤网运行两种运行模式。由于微电网的惯性很小,模式切换过程或孤网下大的负荷投切都会对微电网的频率稳定性造成影响。针对这两种情形,研究超导磁储能系统(SMES)在微电网频率暂态稳定控制中的应用。首先对比分析了超级电容与SMES的性能参数,明确两种储能装置的差别,然后设计了基于虚拟惯量的SMES控制策略、基于模糊控制的超导磁体电流调整策略与SMES容量配置策略。SMES作为微电网的能量缓冲器改善微电网频率的暂态稳定特性。同时,优化调整超导磁体的电流水平,使SMES能够处于最佳的能量/功率水平。仿真算例结果验证了所设计控制策略、电流调整策略与容量配置策略的有效性。

Transient stability control strategy of microgrid frequency based on SMES

Micro-grid, as an important part of smart grid, has two operation modes:grid-connected and isolated. Since the inertia of micro-grid is very small, the transient frequency characteristic of micro-grid will be greatly affected when operation modes switch or high load switches under isolated mode. For these two cases, this paper gives the application of Superconducting Magnetic Energy Storage (SMES) in micro-grid for transient stability control of micro-grid frequency. Firstly, the comparison of super-capacitor and SMES is conducted and the differences of them are clarified, then SMES control strategy based on virtual inertia, current regulation strategy of superconducting (SC) magnet based on fuzzy control and capacity allocation strategy of SMES are designed. SMES, as an energy buffer, can help to improve the transient stability of micro-grid frequency and make SC magnet current at an optimized energy/power level. Simulation results have validated the effectiveness of the proposed control strategy, current regulation strategy and capacity allocation strategy of SMES. This work is supported by Program of State Grid Shandong Electric Power Company (No. 520626160010).