IEEE Power Engineering Review · 1989 · 17 citations · 0 references
EngineeringElectrical EngineeringBuilding DiagnosticsCircuit TheoryPower ElectronicsElectrical CharacterizationElectrical MeasurementElectrical MetrologyElectrical System DiagnosticsElectrical System TestingInsulation SystemsCable InsulationCondition Monitoring Of InsulationInsulation Degradation AssessmentInsulation Degradation DiagnosisInsulation DiagnosticsInsulation Fault DetectionInsulation Fault DiagnosisPolyethylene
Hot-line diagnosis is needed to avoid breakdowns of XLPE (cross-linked polyethylene) cables due to water trees. The authors superposed a low DC voltage on an AC commercial voltage, measured the DC component of the current which passed through the insulation, and discovered that the DC component had a close relationship with the degradation caused by water trees. A hot-line diagnostic measurement system based on this DC superposition method was developed. The old cables that were removed and cables now in use were measured with the system; the results are reported. >