PEA Measurements on 525-kV HVDC Cable: A Comprehensive Data Analysis

Execution of space charge measurements was conducted with the pulsed electro-acoustic (PEA) method, following the guidelines outlined in IEEE Standard 1732. This research marks the first application of the PEA measurement technique on full-size high-voltage-direct-current (HVDC) cables exceeding 100 m in length, representing a significant advancement in cable testing methodologies. According to IEEE 1732, the maximum percentage change in the electric field is evaluated at fixed 3-h intervals to determine when field stabilization occurs. Furthermore, a comprehensive analysis of the acquired data is performed to assess the reliability and robustness of the measurements results. Temporal trends of electric field variations are analyzed, including statistical parameters, such as mean values and standard deviations, over the acquisition intervals of the measurement. The findings reveal that spot measurements lack the statistical significance achieved through a more comprehensive approach to field behavior. Consequently, despite IEEE 1732 serves as a solid guideline, this study suggests a new approach for addressing data variability and measurement accuracy.