Enhancing HVDC Cable Electric Field Assessment with PEA-Based Measurements

Space charge accumulation within the insulation systems of High Voltage Direct Current (HVDC) cables is a significant issue for their long-term reliability and operational efficiency. The internal distribution of electric fields induced by space charge can lead to local stress enhancements, accelerating material degradation and potentially causing failures. This study introduces a novel statistical methodology aimed at improving the evaluation of electric field stabilization. The approach leverages Pulsed Electro-Acoustic (PEA) measurements, enabling the acquisition of space charge profiles at short, regular time intervals. The collected data are analyzed using a comprehensive set of statistical descriptors to characterize the temporal evolution of the maximum electric field variation. By employing a statistical trend analysis framework, the method provides a robust and sensitive technique for detecting stabilization phenomena while effectively filtering out noise and transient fluctuations. Results demonstrate that this approach allows for earlier and more reliable identification of field stabilization compared to conventional spot-check techniques, with potential implications for reducing test durations and enhancing the efficiency of qualification protocols.