非接触式低压线缆漏电故障定位技术

Non-contact technology of low-voltage cable leakage fault location

低压配电线路漏电故障点定位对提高人身安全、避免电气火灾意义重大,但暗敷线缆故障查找困难,亟须解决。提出一种基于信号寻迹原理的非接触式漏电故障定位方法,在剩余电流动作保护器动作后离线状态下,通过对故障线缆施加特定频率的电流信号,利用磁棒线圈传感器采集线缆周围磁场,获取电流信号,并根据电流突变特征判断故障点位置。给出了信号发生装置及信号采集装置的软硬件设计方案,并对注入信号的频率、幅值以及传感器频率特性等关键参数进行了优化配置。通过现场试验,验证了该方法和装置的有效性。

The location of leakage fault point of low-voltage distribution line is of great significance to improve personal safety and avoid electrical fire,but it is difficult to find the concealed cable fault,which needs to be solved urgently.In this paper,a non-contact leakage fault location method based on the signal tracing principle is proposed.In the off-line state after the residual current device acts,the current signal of specific frequency is applied to the faulty cable,the magnetic field around the cable is collected by the magnetic rod coil sensor,the current signal is obtained,and the position of the fault point is judged according to the characteristics of current mutation.The software and hardware design schemes of signal generating device and signal acquisition device are given,the key parameters such as frequency,amplitude of injection signal and frequency characteristics of sensor are optimally configured.The effectiveness of the method and device is verified by field tests.