用于线路差动保护的电流互感器饱和判据

高压、超高压输电线路由于短路容量大，在短线路等特殊情况下区外故障会引起电流互感器饱和，使电流差动保护误动作，采用提高差动门槛及比例制动系数的方法会降低差动保护的灵敏度，增加保护的动作时间。介绍了一种短数据窗与分段积分法相结合的电流互感器饱和识别方法，该方法使电流差动保护能在区外故障，电流互感器饱和时不误动作；在区内故障时可靠动作，快速切除故障。目前，该方法已成功应用于基于32位DSP的数字式光纤电流差动保护装置。

Transformer saturation criterion for line differential protection

CT(Current Transformer) saturation at external fault of short line and other special con-ditions will cause misoperation of line current differential protection for EHV / HV transmission line. Some preventive measures such as increasing setting threshold and enhancing restraint factor will reduce the protection sensitivity and delay the protective action. A CT saturation detection method is introduced,which combines short data window with distinguishing wave distortion. It ensures both sensitivity for internal faults and reliability for external faults,which is successfully applied in digital fiber current differential protection with 32 - bit DSP.