中文摘要：

分析了托克托电厂阻塞滤波器（blocking filter,BF）引发机组异步自励磁的机理,探讨了兼顾抑制异步自励磁和扭振互作用（torsional interaction,TI）的BF改进设计方法。首先分析了BF参数对异步自励磁和TI模态的影响关系,发现增大电抗支路电阻或降低其品质因数有利于降低异步自励磁风险,但同时会在一定程度上削弱BF阻塞TI和暂态扭矩的效果;进而提出了BF改进设计的多目标参数优化思路,并基于特征值分析和优化搜索获得所有方式下能避免自励磁模态发散的最小增补电阻;最后通过串补输电系统的机网联合试验对改进BF进行检验,结果表明：改进BF能有效避免异步自励磁风险,并在正常情况下防止出现TI发散现象,同时验证了现场实测与仿真分析的一致性,为托克托串补和BF的安全投运创造了条件。

英文摘要：

The mechanism of unit asynchronous self-excitation（ASE） caused by blocking filter（BF） installed in Tuoketuo power plant is analyzed,and a method to design improved parameters of BF to suppress ASE and torsional interaction（TI） is researched.Firstly,the influences of BF parameters on ASE and TI modes are analyzed and it is found that increasing resistance in reactance branch of BF or decreasing quality factor of BF reactor is favorable to reduce the risk of ASE,however it will weaken the effect of BF on blocking TI and transient torque to some extent;secondly,a thinking of multi-objective parameter optimization for the improved design of BF is proposed,and based on eigenvalue analysis and optimal search algorithm,by which the divergence of ASE modes under all possible operating conditions can be avoided,the minimum additive resistance is obtained;finally,through field test of a transmission system with series capacitor the improved BF is validated.Test results show that using the improved BF the risk of ASE can be effectively avoided,and under normal conditions the divergence of TI can be prevented,in addition,the consistency between field measurement and simulation analysis is also verified,thus a solid foundation for the secure operation of BF installed in Tuoketuo power plant and series-compensated transmission system is laid.