避免电网连锁解列的全局协调控制策略

Globally coordinated control for preventing cascading split of power system

从解列面和解列时机两方面考虑,提出一种全局协调的解列控制策略。首先通过无故障情况下的在线慢同调分析,掌握系统中发电机群的关联特性;在扰动发生后,利用平均数充分性(MIA)同调识别法获取具体的发电机摇摆分群模式;在发电机的分群模式约束下,把电网中节点间关系表达为拓扑距离,并按照该距离关系完成系统节点的K-Medoids聚类,最终得到满足孤岛功率平衡约束的解列面;为避免电网连锁解列和提前解列,对全网线路运用"激活-闭锁"的策略,使参与解列的线路在检测到可靠的失步信号后,同步速动完成解列。采用IEEE 118节点仿真系统,结果表明在扰动导致系统发生区间振荡时,所提策略成功地将系统解列为满足发电机动态平衡和静态功率平衡的孤网,且决策时间不足0.1 s。

From the aspects of split section and time,a globally coordinated control of power system split is proposed. The correlation among generator groups in system is obtained by the online slow coherency analysis during non-faulty period;the actual grouping pattern of generator swing is detected during faulty period by the MIA（Mean Index Adequacy） coherency identification ;in the constraint of grouping pattern,the relationship among buses is expressed as the topological distance and the K-Medoids clustering of system buses is carried out according to the distance to obtain the split section meeting the constraint of islanding power balance;in order to avoid the cascading split and premature split,the ＂activation-blocking＂ strategy is applied to all lines in system to quickly and simultaneously split all participated power lines after the out-of-step signal of generator is detected. Simulation is carried out for IEEE ll8-bus system and result shows that,when the inter-area oscillation caused by disturbance occurs in system,the proposed strategy successfully islands the system within 0.1 s, satisfying both dynamic and static power balance of generators.