Practical Research On Fault Location In Distribution Networks

To automate fault location in distribution networks and reduce line inspection workload and blackout period, a method for single-phase to ground fault in distribution network is brought out. There are two steps in this method. The first step is fault distance determination. Based on the theory of C-type traveling-wave fault location, and via injecting a signal with high voltage and narrow pulse, waveforms back from the lines are monitored. After comparing the normal and fault waveforms extracted by adaptive filter and differencing, the interval between the beginning end and the fault point is determined. Thus the fault distance can be calculated. The second step is fault branch determination. The definition of feature-waveform in traveling-wave and a method to confirm the structure of simple distribution network is brought out. Fault branch is fixed after analysis to the feature-wave of fault waveform. The results of the two steps make fault location accurately. After theory, ATP simulation, experiments both in lab and on spot, and effectively data analysis, this method is proved correct, as well as its practicality.