Insulation Resilience Response in High-Voltage Power Equipment: Theories, Methods and Application Guidelines

Abstract

The multifrequency voltage (MFV) stress, including switching impulses and harmonics, commonly appearing in the modern power system will stimulate the multifrequency impedance dynamics behaviours of electrical insulation. Therefore, this article presents a novel concept of insulation resilience response (IRR) by employing polymer insulation materials, which may be extended to electrical insulation resilience (EIR). The focus is on understanding reversible recovery performance and supporting physics-informed condition assessment for electrical insulation exposed to MFV. The underlying physical mechanisms and modelling methodologies are integrated to characterise the IRR behaviours of polymer insulation systems. The multifrequency dielectric/impedance properties of different resin dielectrics under diverse temperatures are comparatively investigated as proof-of-concept cases. Furthermore, multidimensional sensitivity indicators are developed to quantify the electrical insulation resilience behaviour. A radar plot representation integrating resilience sensitivity indicators qualitatively assesses the IRR behaviours of polymer insulation systems. Additionally, a quantification methodology, including the resilience index (RI) and time-varied RI (TVRI), is proposed for the reversible recovery performance analysis for electrical insulation, respectively. Ultimately, an application-oriented framework derived from TVRI is provided to analyse the recovery performance evolution behaviours of electrical insulation under complex operating conditions. This offers a key theoretical foundation for insulation performance characterisation and condition analysis for high-voltage power equipment.