基于瞬时值的自适应电流差动保护动作判据的研究

在分析和比较了两种典型的基于瞬时值的电流差动保护的动作判据的工作原理和动作性能的基础上，提出了基于全电流瞬时值和电流故障分量瞬时值结合的自适应判据，并针对瞬时值的特点，提出以时间为轴对判据的制动特性进行实时分析。讨论了该判据中制动系数和门槛电流如何随时间、运行方式和故障状态的变化进行自适应调整的策略，并通过仿真证实自适应判据在灵敏性、可靠性上存在更大优势。

Study on adaptive action criterion of current differential protection based on instantaneous values

After studying and comparing the principle and performance of two typical current differential protection criterions based on current instantaneous values, the adaptive criterion that combines the current instantaneous value with the current fault component instantaneous value is presented. According to the characteristics of instantaneous value, it is suggested that real-time analysis of the restrain characteristics of criterion be made on the time axis. By this method, the strategy that let the restrain coefficient and the threshold current in the adaptive criterion change adaptively with time, operation mode and fault situation is studied. Simulation results show that the adaptive criterion is superior in sensitivity and reliability.