Development of the space charge measurement techniques based on pulsed electric-acoustic method for HVDC power cables

At present, the space charge effect has become one of significant problems in the field of high voltage and insulation, which restricts the development of HVDC power cables. The pulse electric-acoustic (PEA) method has been accepted as a common non-destructive approach to measure the distribution of space charge in solid dielectrics. The basic principle of space charge measurement and characteristics of pulse electric-acoustic method is summarized in this paper. Then, the improvement of the space charge measurement system in recent two decades is introduced from the pulse injection mode, electrode configuration, and the recovery of detected space charge signals. Especially, the application of PEA method in coaxial power cables is expounded. Finally, the prospect of application in HVDC power cables aging evaluation based on the pulse electric-acoustic method is discussed.