This paper describes methodology for the computation of the electromagnetic transients in the high voltage substations, taking into account transients on the substation grounding system. Simulation technology is based on the system decomposition. Interconnections between different subsystems are done in each time step using Thevenin equivalents. Frequency dependent impedance of grounding conductors is represented by the parallel combination of resistance-inductance branches, to enable simulation in the time domain. Lightning overvoltage computation is performed for one particular 123 kV high voltage substation.

This paper presents results of the study dealing with the application of line surge arresters on the quadruple circuit transmission line. Considered transmission line consists of two 275 kV circuits and two 132 kV circuits. Line surge arrester with external gap is installed on the 132 kV circuit. Different arrester installation configuration are studied and compared. Line surge arrester installation strategy is presented.

This paper deals with a particular case of implementing surge arresters with an external gap to cope with the high failure rate of a 110 kV overhead line. Optimization of the number of arresters and their installation location was based on lightning performance computation which is also described.

The lightning performance of 63 kV and 90 kV shielded and unshielded power transmission lines, protected by surge arresters are considered. A specialized software package is used for the computation of the line's fast front transients. A Monte Carlo statistical method, together with a three-dimensional electrogeometric model is used to determine the lightning stroke locations. Different arrester installation configurations are analyzed and compared. The energy duties of the transmission line surge arresters are computed statistically.

The authors propose to process the Fredholm integral equation relating potential to an unknown source density function by the Galerkin weighted residual technique. In essence, this allows them to optimally satisfy the Dirichlet condition over the entire conductor surface. Solving the resulting equations requires evaluation of a second surface integration over weakly singular kernels, and the increased accuracy comes at some computational expense. The singularity issue is addressed analytically for 2-D problems and semi-analytically for axi-symmetric problems. The authors describe how the integrals are evaluated for both the standard and Galerkin boundary element functions using zero, first, and second order interpolation functions. They demonstrate that the Galerkin solution is superior to the standard collocation procedure for some canonical problems, including one in which analytical charge density becomes singular. >

This paper describes the use of the macro elements in the Finite Element Method. Macro elements correspond to the parts of the region and are formed using the triangular isoparametric finite elements (up to fourth order). Some internal nodes are eliminated by the so-called condensation process. Many times, the configuration being analyzed has a part of region which is being repeated (i.e., insulator chains are composed of units of the same shape, etc.). In those cases, the use of macro elements can greatly reduce the total number of unknowns, the amount of input data and the computation time. The complex potential distribution caused by resistive films on the insulator surface is calculated by decoupling the problem in two parts.