A Simplified Approach to Calculate the Earth Fault Current Division Factor Passing Through the Substation Grounding System

The main aim of designing a safe grounding system is to provide a low impedance path to the flow of the earth fault currents without exceeding the operational constraints and equipment limits that will ensure electrical continuity. One of the most significant and well-known parameters to design a safe grounding system in power systems is the exact determination of the maximum earth fault current division factor. This paper presents a simplified and accurate method to calculate the earth fault current division factor in different states of the earth fault occurrence within and the vicinity of the substation under study. In the proposed method, a hybrid overhead-cable line, the impact of the frozen soil, mutual coupling between phase conductors and guard wires, grounding system resistance of adjacent substations, different tower footing resistances, the impact of the phase conductor impedance, and different spans in transmission lines can be considered. In addition, a closed-form formulation is also developed for the occurrence of the earth fault on the transmission line. Finally, details of the analysis results of this study have been compared with other methods in the literature. The validity and accuracy of the proposed approach also have been assayed and confirmed in details.

[1]  A. Geri,et al.  Limitation of cross country fault currents in MV distribution networks by current limiting reactors connected between cable screens and primary substation earth electrode , 2022, Electric Power Systems Research.

[2]  Enrico Pons,et al.  Validation and Testing of an Analytical Formulation to Compute the Reduction Factor in MV Grids , 2020, IEEE Transactions on Industry Applications.

[3]  Mohamad Nassereddine,et al.  Advanced HV Earthing System for Smart Substations , 2019, 2019 International Conference on Electrical Engineering Research & Practice (ICEERP).

[4]  Abderrahmane Haddad,et al.  Analysis of frequency distribution of ground fault-current magnitude in transmission networks for electrical safety evaluation , 2019, Electric Power Systems Research.

[5]  Paulo M. De Oliveira‐De Jesus,et al.  Short‐circuit current distribution analysis using a network model based on a 5×5 primitive matrix , 2019, International Transactions on Electrical Energy Systems.

[6]  Gaetano Zizzo,et al.  On the Interconnections of HV–MV Stations to Global Grounding Systems , 2019, IEEE Transactions on Industry Applications.

[7]  Emtethal Negm Abdallah,et al.  New Methods for Designing a Grounding System for Future Expansion of High Voltage Substations , 2018, 2018 Twentieth International Middle East Power Systems Conference (MEPCON).

[8]  W. Nowak,et al.  Modelling and Analysis of Currents Flowing in High Voltage Power Substations During Ground Short - Circuits , 2018, 2018 14th Selected Issues of Electrical Engineering and Electronics (WZEE).

[9]  Stefano Lauria,et al.  An Equivalent Circuit for the Evaluation of Cross-Country Fault Currents in Medium Voltage (MV) Distribution Networks , 2018, Energies.

[10]  Krung Luewattana,et al.  Effects of Overvoltage on Mesh-Distributed and Edge-Distributed Rods in Rectangular Ground Grid Systems of High Voltage Substations , 2018, 2018 15th International Conference on Electrical Engineering/Electronics, Computer, Telecommunications and Information Technology (ECTI-CON).

[11]  L. Fickert,et al.  Earth fault current distribution and proof method of global earthing systems , 2018, 2018 19th International Scientific Conference on Electric Power Engineering (EPE).

[12]  S. Mangione,et al.  Interconnections criteria of grounding grids in global grounding systems , 2018, 2018 IEEE/IAS 54th Industrial and Commercial Power Systems Technical Conference (I&CPS).

[13]  Jacek Klucznik,et al.  Earth wires currents calculation by tableau analysis , 2017 .

[14]  J. C. Das,et al.  Understanding Symmetrical Components for Power System Modeling , 2016 .

[15]  Maria Vintan,et al.  A Comparative Parametric Analysis of the Ground Fault Current Distribution on Overhead Transmission Lines , 2016 .

[16]  Ljubivoje M. Popovic,et al.  Ground Fault Current Distribution When a Ground Fault Occurs in HV Substations Located in an Urban Area , 2014 .

[17]  Sponsor,et al.  IEEE guide for safety in AC substation grounding , 2013 .

[18]  Jinliang He,et al.  Fault Current-Division Factor of Substation Grounding Grid in Seasonal Frozen Soil , 2013, IEEE Transactions on Power Delivery.

[19]  Junjie Li,et al.  Evaluating ground fault current distribution on overhead transmission lines using an iterative nodal analysis , 2011 .

[20]  S. M. Shahrtash,et al.  Computation of the split factor of earth fault currents by considering the proximity effects , 2010 .

[21]  Zsi,et al.  A COMPLETE PROCEDURE TO DETERMINE EARTH FAULT CURRENT DISTRIBUTION AND SPLIT FACTOR FOR GROUNDING GRID DESIGN OF HV SUBSTATIONS , 2009 .

[22]  S. Mangione,et al.  A Simple Method for Evaluating Ground-Fault Current Transfer at the Transition Station of a Combined Overhead-Cable Line , 2008, IEEE Transactions on Power Delivery.

[23]  L. M. Popovic,et al.  Efficient reduction of fault current through the grounding grid of substation supplied by cable line , 2000 .

[24]  H. R. Seedher,et al.  A practical approach for computation of grid current , 1999 .

[25]  L. M. Popovic,et al.  Practical method for evaluating ground fault current distribution in station, towers and ground wire , 1998 .

[26]  L. Popovic.  Practical method for evaluating ground fault current distribution in station supplied by an unhomogeneous line , 1996, Proceedings of 1996 Transmission and Distribution Conference and Exposition.

[27]  A. P. Meliopoulos,et al.  Computation of Maximum Earth Current in Substation Switchyards , 1983, IEEE Power Engineering Review.

[28]  F. Dawalibi,et al.  Ground Fault Current Distribution Between Soil and Neutral Conductors , 1980, IEEE Transactions on Power Apparatus and Systems.

[29]  D. Mukhedkar,et al.  Ground Fault Current Distribution in Sub-Station, Tower and Ground Wire , 1979, IEEE Transactions on Power Apparatus and Systems.