利用测量电流互感器实现配电网故障电流检测的新方法

提出一种利用测量电流互感器（TA）进行过流故障，故障电流幅值及故障方向检测的新算法。故障检测利用了TA饱和时二次输出电流的间断角，而根据TA在上下半周饱和前的有效信息进行故障电流幅值和方向的计算，电流幅值的估算采用了最小二乘法，可以滤除衰减直流分量和谐波，方向的计算利用了电压，电流故障分量间的相位关系，同时了以上算法基于采样值的实现方法。

FAULT CURRENT DETECTION METHOD USING MEASUREMENT CURRENT TRANSFORMER FOR DISTRIBUTION AUTOMATION

Fault detection and isolation are key functions in distribution autom ation.A new fault detection and calculation algorithm using output data got from m easurem ent current transformer is presented.The fault is detected by measuring the interruption angle of secondary output waveform of current transformer. The fault current amplitude and direction are determ ined using waveform sam ples before current transformer saturation in each half cycle.The fault current amplitude is calculated using least square error method,and its direction is calculated according to the relationship between superim posed com ponents of voltage and current.Test results of a prototype device proved the proposed algorithm.