**Commenced**in January 2007

**Frequency:**Monthly

**Edition:**International

**Paper Count:**31100

##### Effect of Non Uniformity Factors and Assignment Factors on Errors in Charge Simulation Method with Point Charge Model

**Authors:**
Gururaj S Punekar,
N K Kishore Senior,
H S Y Shastry

**Abstract:**

Charge Simulation Method (CSM) is one of the very widely used numerical field computation technique in High Voltage (HV) engineering. The high voltage fields of varying non uniformities are encountered in practice. CSM programs being case specific, the simulation accuracies heavily depend on the user (programmers) experience. Here is an effort to understand CSM errors and evolve some guidelines to setup accurate CSM models, relating non uniformities with assignment factors. The results are for the six-point-charge model of sphere-plane gap geometry. Using genetic algorithm (GA) as tool, optimum assignment factors at different non uniformity factors for this model have been evaluated and analyzed. It is shown that the symmetrically placed six-point-charge models can be good enough to set up CSM programs with potential errors less than 0.1% when the field non uniformity factor is greater than 2.64 (field utilization factor less than 52.76%).

**Keywords:**
High Voltage,
charge simulation method,
Assignment factor,
Numerical field computation,
Non uniformity factor,
Simulation errors

**Digital Object Identifier (DOI):**
doi.org/10.5281/zenodo.1084820

**References:**

[1] H Singer, H. Steinbigler P. Weiss, "A change simulation method for the calculation of high voltage fields", IEEE trans, PAS vol.93, 1974, pp1660-68.

[2] Nazar H Malik, "A review of the charge simulation method and its application", IEEE Transaction on electrical insulation, Vol.24, No.1, 1989, pp. 1-20.

[3] S. Chakravorty, "Charge Simulation Method: a critical overview", Ie (I) journal-el, Vol. 78, March 1998, pp. 210-214.

[4] E. Kuffel, W.S.Zeangle & J.Kuffel, "High Voltage Engineering fundamentals", Newnes, An imprint of Butterworth-Heinemann, A division of Reed Educational and Publishing Ltd, Woburn, MA. 2000, pp.254-269.

[5] H Anis, A Zeitoun, M El-Ragheb m and El-Desouki, "Field calculations Around Non-Standard Electrodes Using Regression and Their Spherical Equivalence", IEEE Trans on PAS, Vol.PAS-96, no.6, November- December 1977, pp.1721-1730.

[6] A Yializis, E.Kuffel, P H Alexander, "An Optimized Charge Simulation Method for the Calculation of High Voltage fields", IEEE Transaction on PAS-97, 1978, pp. 2434-40.

[7] Y L Chow and C Charalambous, "Static-field computation by method of optimized simulated images", Proc. IEE, Vol.126, No.1, 1979, pp.123- 125.

[8] M R Iravani, M R Raghuveer, "Accurate Field Solution in the Entire Inter electrode Space of A Pod-Plane Gap Using Optimized Charge Simulation", IEEE Transactions on EI Vol.EI-17 No.4, August 1982, pp. 333-337.

[9] M M Abouelsaad, M M El Bahy: "Accurate Field Computation of Needle-Plane Gaps using an Optimized Charge Simulation Method", Conference on Electrical Insulation and Dielectric Phenomena, 2000, pp506-509.

[10] Ryo Nishimura, Katsumi Nishimori, Naganori Ishihara, "Automatic arrangement of fictitious charges and contour points in charge simulation method for two spherical electrodes", Journal of electrostatics 57, 2003, pp. 337-346.

[11] M.Th.El-Mohandes, H Okubo, "Error analysis based on the interaction between simulating charges in the CSM for the Electric-Field Calculation of HV Apparatus", European Transactions on Electric Power, ETEP, Vol.4, No.6, November/December 1994, pp565-570.

[12] H. McL Ryan and C.A. Welley, "Field Auxiliary Factors for simple electrode geometries". Proc IEE Vol 114, no.10, Oct, 1967, pp 1529- 1536.

[13] Y. Qui, "Simple expression of field nonuniformity factor for hemisphereically capped rod-plane gap", IEEE Trans. Electrical Insulation, Vol.21, No.4, 1986, pp. 673-675.

[14] Christopher R Houck, Jeffery A. Joines and Michael G.Kay, A genetic algorithm for function optimization: A Matlab implementation, North Carolina State University, available at http://www.ie.ncsu.edu/mirage/GAToolBox/gaot//papers/gaotv5.ps.