Experimental Substantiation of the Calculation Procedure of Normalized Parameters of Grounding Device Based on the Three-Layer Soil Model

Abstract

Purpose. Experimental substantiation of the possibility of using the calculation procedure of normalized parameters grounding devices on the basis of a three-layer model soil. Methodology. The research was based on comparison of the results of experimental measurements for the existing high voltage energy facilities of Ukraine with the results of the calculation. Results. Comparison showed that the average error decreased from 18 % for the two-layer model to 10 % for the three-layer model. The analysis of the calculated and experimentally determined values of the touch voltage showed a high degree of coincidence. Originality. The adequacy of the calculation procedure of the normalized parameters of the grounding device for model with three-layer soil is substantiated by the results of experimental research on the existing energy objects. Practical value. The obtained results allow us to use calculation procedure to create software to determine with increased accuracy the normalized parameters of grounding device located in three-layer soils. References 10, tables 4, figures 3.

Simulation of electromagnetic processes in the grounding system with a short circuit in the operating high-voltage substation

“…The use of a mathematical model of GS [6], located in a three-layer soil, allows to directly (without equivalentization) perform a calculation for 80 % of the existing energy facilities in Ukraine and determine the resistance of GS with an error of up to 10 % (confirmed according to the calculation data of more than 50 substations with a voltage class 35 kV). Comparison with the experimental value of the contact voltage showed more than 90 % falling into the calculated range for the GS of three test substations [3].…”

“…Problem formulation. To monitor the state and assess the efficiency of the grounding system (GS) of operating power facilities, the electromagnetic diagnostics (EMD) [1,2] is used, which involves three stages: experimental, calculated, and the stage of issuing recommendations [3]. In the process of research, the topology of the GS is determined, as well as the normalized parameters (NP) of the GS, such as the GS resistance, the voltage across the GS, and the touch and step voltages.…”

“…The assessment of the adequacy of the developed mathematical model and the created software package was carried out by comparing the results of experimental studies for operating high-voltage power facilities in Ukraine with the calculation results, and is given in [3].…”

“…The analysis was carried out on six equipment of substations with voltage class 150 kV. In this case, the traditional method of the set of experimental data was used to assess the adequacy of the mathematical model of the GS which is presented in [3] (see Fig. 7) with measuring current -5,13 A.…”

Determination of the scope of the experimental-calculation method for measuring the touch voltage

“…The calculated method is based on the results of the GS EMD: the current structural state [9], additional experimental characteristics of the GS for assessing the adequacy of the calculation model [10,11], and the EPC found using vertical electrical sounding (VES) [12]. The advantages of the method are the ability to determine the normalized parameters of the GS in all modes with a real SC current on all equipment with high accuracy (94 %), as well as checking the effectiveness of the developed recommendations [9].…”