Analysis of Polymer Surface Modifications due to Discharges Initiated by Water Droplets under High Electric Fields

This paper investigates the influence of various parameters on the behaviour of water droplets on polymeric surfaces under high electric fields. An inclined plane test was carried out to understand the droplet behaviour in strong electric field. Parameters such as water droplet conductivity, droplet volume, polymeric surface roughness and droplet positioning with respect to the electrodes were studied. The flashover voltage is affected by all aforementioned parameters. The droplet positioning is in some cases more vital than the droplet volume. Surface damages were analysed using Scanning Electron Microscopy (SEM) studies and by Energy dispersive X-ray Analysis (EDAX). It is observes that magnitude of discharge have direct influence on amount of surface da




References:
[1] Kind, D. - Kaerner, H.: High Voltage Insulation Technology,
Braunschweig: Eds. Vieweg, 1985.
[2] Danikas, M. G.:Surface Phenomena on Resin-Type Insulators under
Different Electrical and Non-electrical Stresses in the Early Stage of
Ageing", Facta Universitatis 13 (2000), 335-352.
[3] Karakoulidis, K. - Danikas, M. G. - Rakitzis, P.: Deterioration
Phenomena on Insulating Surfaces due to Water Droplets", Journal of
Electrical Engineering 56 (2005), 169-175.
[4] Danikas, M. G. - Rakitzis, P. - Karakoulidis, K.: Study of Parameters
Related to Deterioration Phenomena due to Water Droplets on Polymeric
Surfaces", Journal of Electrical Engineering 57 (2006), 130-137.
[5] Danikas, M. G.: Ageing Properties of Silicone Rubber Materials Used in
High Voltage Composite Insulators, Journal of Electrical and Electronics
Engineering (Australia), 15 (1995), 193-202.
[6] Kloes, H.-J. - Koenig, D. - Danikas, M. G.: Electrical Surface
Discharges on Wet Polymer Surfaces, Proceedings of the 8th
International Symposium of Gaseous Dielectrics, Virginia beach,
Virginia, USA, pp. 489-495, June 1998.
[7] Koenig, D.: Surface and Aging Phenomena on Organic Insulation under
the Condition of Light Contamination and High Electric Stress, Proc. of
the Nordic Insulation Symposium, Vaasa, Finland, pp. 17-35, June 1994.
[8] Hartings, R.: The AC-Behavior of a Hydrophilic and Hydrophobic Post
Insulator during Rain, IEEE Winter Power Meeting, New York, USA,
1994.
[9] Dan Windmar: Water Droplet Initiated Discharges in Air, Ph. D. Thesis,
Uppsala University, Uppsala, Sweden, 1994.
[10] Schutte, T.: Water Drop Dynamics and Flashover Mechanisms on
Hydrophobic Surfaces, Proc. of the Nordic Insulation Symposium,
Vasteras, Sweden, paper 8.1, June 1992.
[11] Mason, J. H.: Discharges, IEEE Transactions on Electrical Insulation, 13
(1978), 211-238.
[12] Vlastos, A. - Gubanski, S.: Surface Structural Changes of Naturally
Aged Silicone Rubber and EPDM Composite Insulators, IEEE
Transactions on Power Delivery, 6 (1991), 888-900.
[13] Keim, S. - Koenig, D. - Hinrichsen, V.: Experimental Investigations on
Electro-hydrodynamic Phenomena at Single Droplets on Insulating
Surfaces, Annual Report of the Conference on Electrical Insulation and
Dielectric Phenomena, Albuquerque, New Mexico, USA, pp. 133-136,
October 2003.
[14] Keim, S.: Optical Diagnostic of Single Droplets on Polymeric Insulating
Surfaces in an Electric Field to Describe the Phenomena of the
Beginning of Aging Mechanisms, Ph. D. Thesis, Darmstadt University
of Technology, Darmstadt, Germany, 2003 (in German).