Electrical performance evaluation of plasticized polyolefin formulation developed for manufacturing surge arresters housings

The performance and reliability of the electric power systems can be enhanced with the development of new polymer formulations, offering new concepts in equipment housing design and application. This paper reports the electrical and physicochemical properties of plasticized formulations based on HDPE, developed specifically for surge arresters housings. Plasticized HDPE surge arrester housings, 15 kV, were manufactured at ISO-9001 by one-shot injection molding technique. HDPE housed surge arresters were submitted to performance tests according to IEC 60.099-4 and exposed to artificial electrical aging tests and then physicochemically and electrically characterized. The physicochemical characterization comprised analysis by Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), wide-angle X-ray diffraction (WAXRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle measurements. The FTIR results confirm the microstructural modifications of the aged HDPE due to oxidation phenomena, probably involving the formation of alcohol or carboxylic groups at surface level of surge arresters housings. The DSC technique shows no significant variation of the HDPE amorphous and crystalline content as a function of the electrical aging conditions. The TGA kinetics analysis shows significant changes in the activation energy for thermal degradation of the electrical aged and unaged HDPE surge arresters housings. The results obtained have demonstrated that the plasticized HDPE formulation has good stability at high electrical field and appears to be suitable for use in manufacturing surge arresters housings.