变压器差动保护中电流互感器饱和的综合判据

针对电流互感器(TA)饱和对变压器差动保护造成的不利影响，总结分析了常用的谐波制动法、时差法和附加制动区法这3种TA饱和识别方法的优缺点，在时差法或附加制动区法作为主判据的基础上，以谐波制动法的判别结果作为必要条件提出了变压器差动保护中TA饱和的综合判据。该判据提高了TA饱和的识别率，且在TA饱和延时闭锁差动保护期间可以对变压器区内故障做出快速反应。作者还提出了在静模试验中校验TA饱和判据的新方法，可以不依赖于动态模型进行程序调试，最后通过动模试验验证了该判据的可行性。

Study on Comprehensive TA Saturation Criterion for Transformer Differential Protection

To remedy the adverse impact of TA saturation on transformer differential protection, the advantages and disadvantages of three commonly used methods to identify TA saturation, i.e., harmonic restraint method, time difference method and additional restraint region method, are analyzed. On the basis of taking time difference method and additiona restraint region method as principal criteria, a comprehensive criterion for saturation of TA in transformer differential protection is proposed in which the identification result of harmonic restraint method is regarded as necessary condition The proposed criterion improves the reliability of TA saturatior identification and can quickly react to the internal fault while the time-delay blocking of transformer differential protection occurs due to TA saturation. The authors also put forward a new approach to verify the criterion for TA saturation during static simulation test, by which the program debugging is independenl on dynamic model. The feasibility of proposed criterion for TA saturation is validated by dynamic simulation.