Comparison between PEA and PWP method of space charge measurement in model cable

The distribution of electric field in cable insulation under DC field is introduced, the non-uniform radial field and space charge accumulation lead to the distortion of electric field in cable insulation, so it is important to investigate the distribution of space charge in model cable insulation. It is indicated that the signal of space charge measurement is weak by pulsed electro-acoustic method (PEA method), the signal-to-noise ratio (SNR) is low, and it is difficult to measure space charge in model cable at high temperature. The further analysis revealed that the signal of space charge measurement is strong, i.e. the SNR is high by pressure wave propagation method (PWP method), and it is the appropriate method for the measuring space charge in thick cable insulation. In addition, PWP method is also the appropriate method for measuring space charge in model cable at high temperature.