Junhua Luo

Partial Discharge Pattern Characteristic of HV Cable Joints with Typical Artificial Defect

Insulation failure of XLPE cable system, particularly in joints and terminations, mostly attributes to local defects resulted from inadequate manufacturing or poor installation workmanship. Since it is well-acknowledged that partial discharge (PD) has a relationship with the discharge source (fault or defect), PD detection and pattern recognition have been widely accepted as a means to provide information on both the type and severity of defects or potential failures, which is further expected to give advice on repair or replacement of cable accessories. This paper presents a laboratory experiment on HOkV XLPE cable joints with artificial typical defects and their partial discharge pattern characteristic. PD patterns and statistical operators of these defects shows dissimilarity, which can be utilized as samples for further on-site PD pattern recognition.

Partial Discharge Pattern Analysis Based on 2-D Wavelet Transform

Partial discharge (PD) measurement and pattern recognition for insulation defect is an effective tool for condition assessment. The patterns obtained by PD detection system contain characteristic features of the insulation defect. This paper presents a PD experiment of semi-conductor layer tip defect in the joint, and applies a new feature method based on 2-D wavelet decomposition and pattern edge detection. Research shows that this method has robust capability to extract main information from complicated online PD patterns.