配电网输电线路反时限过流保护探讨

讨论了传统的反时限过电流保护的实现方法 ,如分区查表法 ,插值方法的实现方式及其误差特性 ;提出了适用于配电网的过电流保护的冷备用方案 ;论述了一种用DSP技术实现反时限特性曲线的新技术 ,提出了在DSP技术下计算动作时限的新方法。该方案能够根据故障电流的大小实时计算出过电流保护的动作时限 ,所需要的内存较小 ,且计算速度快 ,在配电网的自动化技术中 ,具有较强的实用性

Discussion of inverse overcurrent protection for transmission line in distribution system

The traditional implementation methods of inverse overcurrent protection such as zonal table lookup method,interpolation method and their error characteristic are discussed. On this basis,Cold pick up scheme of the inverse overcurrent protection suitable for the distribution system was proposed.We make full use of DSP technology to implement the inverse curve and propose a new method to calculate the operation time of the protection on the base of DSP.This method can in real time calculate the operation time of the overcurrent protection according to the fault current.The EPROM needed is small;calculation is fast and accurate.This scheme is very practicable in automation technology of distribution system.