Recurrent plot for leakage current investigation and performance monitoring of HV insulator model under discontinuous pollution

In this paper, the Recurrent Plot (RP) method is used to monitor polluted insulator performance. LC acquisition is first carried out on 1512L insulator model, under various lengths (5, 10, 15, 20 and 25 cm) of a polluted layer deposited at HV side. Next, the high frequency component of LC is extracted and reconstructed in an appropriate phase space. RP is then computed. For a polluted layer length up to 15 cm, RP diagram consists in dispersed low density recurrent points indicating the faint discharge activity and thus, the healthy insulator condition. However, for a polluted layer length more up to 15 cm, RP is composed of intense recurrent points and wide white bands. The dense recurrent points indicate the apparition of stronger discharges, while the white bands announce the presence of arcing discharges on the insulating surface. RP technique, based on LC frequency representation, provides an efficient and rapid analysis of the insulator condition. RP represents an excellent alternative to classical signal processing methods for polluted insulator performance monitoring.