风电基本不参与系统调频,送出线路因故障断开后,形成含风电的孤网带负荷独立运行。由于盈余功率的存在,孤岛系统的频率、电压等很快失稳,造成孤岛检同期重合失败。基于此,建立了孤网侧最大重合频率及重合时间的表达式,结合含风电孤网送出线的输送功率,基于等面积法则提出了满足重合要求的边界条件。结合风电场电气特性,提出风电场采用高周切机策略以增加孤网维持暂稳的时间,送出线采用基于最大合闸频率的准同期重合策略。最后构建了含风电的孤网模型,通过仿真验证重合策略的正确性,表明该方法可有效提高重合成功率。
Because wind power usually cannot participate in frequency regulation, island system with wind power operates with loadindependentlyafter outgoing lines disconnected. Frequency and voltage in island system affected by surplus power will lose stability soon,resulting in synchronous reclosing failure. Expressions of calculating maximum reclosing frequency and reclosing time are set up. Combining with transmission power of outgoing lines in island system and based on equal area principle, boundary condition meetingreclosing requirement is proposed. Combining with characteristics of wind power,a reasonable strategy is put forward that wind farm adopts high-frequency cutting machine to increase temporarystability time of island system and outgoing line adopts quasi-synchronization reclosing based on maximum reclosing frequency.A model of island system with wind power is established, and simulationverifies validity of the strategy. The new strategy can improve success rate of reclosing.