Computations of soil temperature rise due to HVDC ground return

ABSTRACT

The purpose of this paper is to present an application which historically, did not make use of computing methodology in the solution of design problems. The design of High Voltage Direct Current (HVDC) ground electrodes involves the careful selection of several parameters in order to meet strict operating constraints. In particular, the operation of HVDC ground electrodes, results in a rise of the surrounding soil temperature which must be reasonably computed so as to permit safe operation of the grounding network.

The classical approach to this design issue was to make several simplifying assumptions and thereby obtain a closed form solution which approximated the situation. Unfortunately, this technique is extremely limited in its scope and the accuracy of solution is dependent on the simplifications made in order to obtain a solution.

The technique presented in this paper uses a numerical model to represent the system to be studied. This approach provides extreme flexibility, thus a minimal of assumptions are needed in order to accurately obtain realistic solutions to the problem. The complexity of the numerical model however, requires substantial computing capabilities. Symbols g = heat generated, W/m³ p = soil electrical resistivity, Ω - m J = current density, A/m² T = temperature of the medium, °C k = thermal conductivity, W/°Cm α = thermal diffusitivity, m²/s C_p = specific heat, J/kg°C d = mass density, kg/m³ V = electrical potential, V λ = over relaxation factor

References

1. 1.E.W. Kimbark, "Direct Current Transmission" (book), John Wiley & Sons, New York, 1971, pp. 450-455
2. 2.R. Rudenberg, "Transient Analysis of Electrical Power Systems"(book), McGraw-Hill, 1950, pp. 336-339
3. 3.M.N. ozisik, "Basic Heat Transfer" (book), McGraw-Hill, 1977, pp. 128-147
4. 4.J.P.Holman,"Heat Transfer" (book), McGraw-Hill, 1972, pp. 72-76
5. 5.B.D. Popovio, "Introductory EngineeringElectromagnetics" (book), Addison-Wesley,1971, pp. 202-203
6. 6.E.D. Sunde, "Earth Conduction Effects in Transmission Systems" (book), Dover, 1967, pp. 91-94
7. 7.G. F. Tagg,"Earth Res istances"(book),Whitefriars Press, 1964, pp. 1-12
8. 8.EPRI EL-2020,roj ect 1467-I, "HVDC Ground Electrode Design" International Engineering Company,San Francisco, 1981, pp. 4.~-4.6
9. 9.IEEE 8td 442-1981,"IEEE Guide for Soil Thermal Resistivity Measurements", New York: IEEE Press, 1981: PD- 6-7
10. 10.R.W. Hornbeck,"14umerical Methods" (book), Quantum Publications Inc., 1975, pp. 101-104

Index Terms

• Applied computing

  • Physical sciences and engineering

    • Engineering

• Computer systems organization

  • Architectures

    • Distributed architectures

      • Grid computing

    • Parallel architectures

      • Multicore architectures

    • Serial architectures

      • Superscalar architectures

• Computing methodologies

  • Modeling and simulation

    • Simulation types and techniques

      • Massively parallel and high-performance simulations

  • Symbolic and algebraic manipulation

    • Symbolic and algebraic algorithms

      • Linear algebra algorithms

• Mathematics of computing

  • Mathematical analysis

    • Numerical analysis

      • Computations on matrices

• Software and its engineering

  • Software organization and properties

    • Software system structures

      • Distributed systems organizing principles

        • Grid computing