Correlative Calibration for Space Charge Measurement in Cables Using PEA Method

As one of the key steps in the development of DC cables, calibration methods for space charge measurements have not been sufficiently investigated. The authors have studied the possibility of obtaining a calibration reference signal in the presence of space charge fluctuations, by correlating the PEA signal with frequency components extracted from bias voltage variations with the use of the pulsed electroacoustic (PEA) method. In this paper, the space charge in the cable with insulation thickness of 10 mm was measured and calibrated. The results at room and high temperatures (conductor temperature of about 90°C) were compared.