Two-Dimensional Space Charge Measurement of Scaled Cable Joint Model and Signal Compensation

This study deals with the measurement of space charge in a scaled cable joint model as a step towards its application to full-scale HVDC cable joints. Recently, the new pulse electroacoustic (PEA) device has been shown to be up to four times more sensitive than the conventional method, making it an ideal device for measuring space charge in the scaled HVDC cable joint model. Based on its high measurement performance, we assembled a prototype consisting of a 16-channel piezoelectric sensor array capable of automatically scanning along the scaled cable joint model, making it easier to measure the space charge distribution quickly and accurately. The 16-channel piezoelectric sensor array, each with a 10 mm aperture, was used to scan the cable joint model specimen from the deflector to the steering electrode region. Moreover, the study will show a precise signal processing, including deconvolution, corrections for acoustic divergence, acoustic attenuation and dispersion, and local pulse electrical stress to determine charge density distribution. Whereas the result will identify the build-up of interfacial charge through the use of dynamic 2-D imaging.