Practical experience with fault location in MV cable network

As the major cause of interruption time is a fault in the MV network, the Dutch grid operator Alliander puts effort in faster location of faults in these networks, which entirely consist of buried cables. After several pilots a fault location system was implemented in 10 substations equipped with the SASensor protection and control system. The SASensor system uses a high sampling rate and collects event recording data as soon as a set point for the current is exceeded. Therefore also events like inrush currents and transients due to self extinguishing single phase faults are recorded. The data processing routine in the substation is able to distinguish between a real fault and other events. The process is fully automated. All events are shown on a PC screen and, in case of a fault, printed on paper. The system performs according requirements on accuracy and processing time.