Experimental investigation of surface charging and electric charge decay on HVDC outdoor polymeric insulator under different air humidity and aging conditions

• Published in: Materials research express 2019-02, Vol.6 (2), p.25316
• Main Authors: Mahmoodi, Jamshid, Mirzaie, Mohammad, Shayegani Akmal, Amir Abbas
• Format: Article
• Language: English
• Subjects: aged insulator; charge decay; corona charging; polymeric insulator; surface charges
• ISSN: 2053-1591; 2053-1591
• DOI: 10.1088/2053-1591/aaf26e

In this paper, electric charge decay and surface charging on outdoor Silicon Rubber (SiR) insulator used in high voltage direct current (HVDC) applications is analyzed under different conditions. According to the theoretical and experimental investigations, flashover is worsened by the accumulation of the charge on the insulator surface. Thus, to prevent unexpected flashover occurrence, the surface charge of the insulator should be carefully investigated. In this paper, effects of the relative air humidity on the electric charge decay in case of the outdoor polymeric insulator have been investigated. Therefore, the surface of the insulator is initially charged by DC corona under varying relative air humidity, and then electric charge decay is measured. In addition, the process of determining surface charge decay on aged insulator is studied. An experimental comparison has also been drawn between the surface charge resulting from DC corona charging on the aged and non-aged insulator. It's been proven from the results that aging has a significant effect on surface charge decay after corona charging.