Two-dimensional Space Charge Measurement of Scaled Cable Joint Model

Abstract

In order to establish a space charge measurement method for a full-size HVDC cable joint, a two-dimensional space charge measurement of a reduced joint model was attempted. A prototype of a high sensitivity PEA scanning cell using a polymer acoustic coupler combined with a 16-channel piezoelectric sensor array has been created, and applied to a scaled joint model. A pulse voltage was applied to the shield layer of the joint maintaining the cable screen at ground potential. Deconvolution was applied to 16 waveforms to create a 2D image representing the charge distribution. The measurement result was subjected to a compensation taking the result of finite element field analysis into account. An internal charge distribution including an interfacial charge was successfully indicated as a 2D cross-sectional profile.