Development of a pulsed electro-acoustic space charge measurement system for extruded cables

Measurement systems for determining the space charge distribution within the insulation of full-size extruded HVDC cables gained significantly more importance over the last years. This is induced by an increasing number of HVDC cable projects and increasing voltage levels and hence insulation thicknesses of these cables available on the market. Driven by this evolution, this contribution focuses on the development of a space charge measurement system based on the pulsed-electro-acoustic (PEA) method. The system is designed in order to realize space charge measurements on 30 mm thick cable insulations in principle. Besides tackling critical issues of the hardware and software development, deconvolution and acoustic recovery, some example measurements, which were conducted on a 80kV XLPEinsulated DC-cable with 8 mm insulation thickness, are shown to validate the performance.