Dynamic model to predict AC critical flashover voltage of nonuniformly polluted insulators under thermal ionization conditions

This paper presents a theoretical dynamic model based on the Hampton criterion and Mayr s equation for predicting the critical values of flashover on the surface of nonuniformly polluted cap and pin porcelain insulators. The nonuniform pollution layer on the surface of the insulator, the number of disk insulator units, and the geometry of the insulator such as diameter and ribs are the important factors used for prediction. Two types of pollution layer configuration, linear and graded, are introduced as nonuniform pollution layers. The influences of the nonuniform pollution layer on critical flashover voltage are investigated. Furthermore, a random value is added to the surface discharge length during propagation in order to consider the effects of the wind and thermal convection on surface discharge length. The specifications of a real porcelain disk insulator are used in the model. Finally, the estimated results of the proposed model are compared with the measured data of the tests in order to validate the proposed model.

PDF

___

[1] Johns AT, Aggarwal RK, Song YH. Improved techniques for modeling fault arcs on faulted EHV transmission system. IEE P-Gener Transm D 1994; 2: 148-154.
[2] Obenaus F. Contamination flashover and creepage path length. Deustsche Elektrochnik 1958; 12: 135-136.
[3] Boehme H, Obenaus F. Pollution Flashover Tests on Insulators in the Laboratory and in Systems and the Model Concept of Creepage Path Flashover. Paper No. 407. Paris, France: CIGRE, 1966.
[4] Neumarker G. Contamination State and Creepage Path. Berlin, Germany: Deustsche Akad. Wissenschaft.
[5] Alston LL, Zoledziowski S. Growth of discharges on polluted insulators. P IEE 1963; 9: 325-326.
[6] Hampton B. Flashover mechanism of polluted insulation. P IEE 1964; 111: 985-990.
[7] Rizk FAM. Analysis of dielectric recovery with reference to dry zone arc on polluted insulators. In: IEEE PES Winter Power Meeting; 1971. New York, NY, USA: IEEE.
[8] Claverie P. Predetermination of the behavior of the polluted insulators. IEEE T Power Ap Syst 1971; 90: 1902-1908.
[9] Zhicheng G, Renyu Z. Calculation of dc and ac flashover voltage of polluted insulators. IEEE T Electr Insul 1990; 25: 723-729.
[10] Rizk FAM. Mathematical models for pollution flashover. Electra 1981; 78: 71-103.
[11] Mayr O. Beitr¨age zur Theorie des statischen und des dynamischen Lichtbogens. Archiv fur Elektrotechnik 1943; 37: 588-608 (in German).
[12] Sundararajan R, Gorur RS. Dynamic arc modeling of pollution flashover of insulators under dc voltage. IEEE T Electr Insul 1993; 28: 209-218.
[13] Bo L, Gorur RS. Modeling flashover of AC outdoor insulators under contaminated conditions with dry band formation and arcing. IEEE T Dielect El In 2012; 19: 1037-1043.
[14] Dhahbi N, Beroual A. Flashover dynamic model of polluted insulators under ac voltage. IEEE T Dielect El In 2000; 7: 283-289.
[15] Aydogmus Z, Cebeci M. A new flashover dynamic model of polluted HV insulators. IEEE T Dielect El In 2004; 11: 577-584.
[16] Yawei L, Hao Y, Qiaogen Z, Xiaolei Y, Xinzhe Y, Jun Z. Pollution flashover calculation model based on characteristics of AC partial arc on top and bottom wet-polluted dielectric surfaces. IEEE T Dielect El In 2014; 21:1735-1746.
[17] Qing Y, Wenxia S, Caixin S, Lichun S, Qin H. Modeling of DC flashover on ice-covered HV insulators based on dynamic electric field analysis. IEEE T Dielect El In 2007; 14: 1418-1426.
[18] Volat C, Farzaneh M, Mhaguen N. Improved FEM models of one- and two-arcs to predict AC critical flashover voltage of ice-covered insulators. IEEE T Dielect El In 2011; 18: 393-400.
[19] Taheri S, Farzaneh M, Fofana I. Dynamic modeling of AC multiple arcs of EHV post station insulators covered with ice. IEEE T Dielect El In 2015; 22: 2214-2223.
[20] Raizer YP. Gas Discharge Physics. Berlin, Germany: Springer, 1991.
[21] Welty JR, Wicks CE, Wilson RE, Rorrer GL. Fundamentals of Momentum, Heat and Mass Transfer. Hoboken, NJ, USA: Wiley, 2008.
[22] Farzaneh M, Chisholm WA. Insulators for Icing and Polluted Environments. Hoboken, NJ, USA: Wiley, 2009.
[23] IEEE. Std. 4. IEEE Standard Techniques for High Voltage Testing. New York, NY, USA: IEEE Press, 2013.
[24] IEC. Std. 60507. Artificial Pollution Tests on HV Insulators to be Used on AC Systems. Geneva, Switzerland: IEC,1991.