Two STW doctoral students, working with KEMA, Continuon and ENECO, have developed a device that continuously isolates weak sections of distribution cables. This will allow network managers to act preemptively to prevent short-circuits. This improves the reliability of the network
at less expense. Network managers try to replace weak sections of distribution cables before a short-circuit develops. This presently occurs by measuring the most important cables while they are out of service. This is both time consuming and expensive. Furthermore, many defects are not detected. Through the research of Jeroen Veen and Peter van der Wielen, many network companies will be able to monitor their cables in the future while they are in service and at lower cost. Their research has led to a working prototype that has since been put into development by a manufacturer. Short circuit
The insulation of electrical cables degrades with age. This degradation can lead to a short circuit. At the location wear the insulation exhibits deficiencies, high-frequency electrical charges develop. These charges generate current pulses that propagate to the ends of the cable. The new measurement system consists of two special sensors that measure these current pulses at both ends. The measurement results go to a special server that calculates if and where problems exist. Arrival time
To determine the exact location, the difference between the arrival time of two current pulses is measured. The researchers from Eindhoven developed a method by which the two measurement signals can be synchronized so that the time difference can be determined. This is the first measurement system that does this while the cable is in service. The first measurements are very promising. The electrical engineers were able to localize a defect in a 300-meter-long cable to within a half meter. It is expected that cables of up to 4 km in length can be measured.
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