Insulation Design Of Transmission Lines Research Articles

Flashover Performance Test with Lightning Impulse and Simulation Analysis of Different Insulators in a 110 kV Double-Circuit Transmission Tower

The flashover performance of insulators is the foundation of the calculation of precise lightning protection. The material and structure of an insulator affect its flashover performance but the research on the differences in the flashover performance of different insulators and the analysis of the reason for these differences have not been clear. In this paper, lightning impulse flashover tests of two types of insulators (composite and glass insulators) were carried out in the National Engineering Laboratory (Kunming) for Ultrahigh-voltage Engineering Technology. In these tests, the insulators were hung in a 110 kV double-circuit transmission tower and a standard lightning impulse (1.2/50 μs) was applied to the insulators. The discharge path and the 50% impulse flashover voltage of the insulators were recorded. At the same time, the electric fields in the vicinity of different insulators were calculated using the finite element method with COMSOL Multiphysics. The electric field distribution and the uneven coefficient were analyzed. Combined with the flashover test data and the electric field simulation, the relationship between the flashover performance (discharge path and 50% impulse flashover voltage) and the electric field (electric field distribution and uneven coefficient) is found. The simulation results are in accordance with the test data and the conclusions can provide useful references for the external insulation design of transmission lines and the optimization of insulators.

Experimental and analytical studies on lightning surge characteristics of a buried bare wire

AbstractLightning surge analysis is very important from the viewpoint of insulation design of transmission lines and substations. Lightning surge analysis has many parameters, which include lightning surge characteristics of transmission towers, back flashover phenomena at an arcing horn, characteristics of footing resistance, effects of corona wave deformation, characteristics of electromagnetic fields caused by lightning, and other parameters. This paper describes experimental and analytical studies on lightning surge characteristics of a buried bare wire. The measurement of the lightning surge characteristics of the buried bare wire is carried out under various experimental conditions. The experimental parameters controlled in these experiments include earth resistance, length of the buried bare wire, and waveform of the injected current. The measured results are compared with analytical results based on the theoretical study by Sunde. A comparison of the measured results with the analytical results shows good agreement. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 164(3): 35– 41, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20532

Experimental and Analytical Studies on Lightning Surge Characteristics of a Buried Bare Wire

Lightning surge analysis is very important from the viewpoint of insulation design of transmission lines and substations. Lightning surge analysis has many parameters, which include lightning surge characteristics of transmission towers, back flashover phenomena at an arcing horn, characteristics of footing resistance, effects of corona wave deformation, characteristics of electromagnetic fields caused by lightning, and other parameters. This paper describes experimental and analytical studies on lightning surge characteristics of a buried bare wire. The measurement of the lightning surge characteristics of the buried bare wire is carried out under various experimental conditions. The experimental parameters controlled in these experiments include earth resistance, length of the buried bare wire and waveform of the injected current. The measured results are compared with analytical results based on the theoretical study by Sunde. A comparison of the measured results with the analytical results shows good agreement.

Comparative studies of lightning performance of a quadruple-circuit dual voltage 275/132 kV transmission line design with wooden crossarms

This paper describes a transmission line lightning performance analysis program QCORTL which is able to predict single and multi-circuit flashover and outage types and rates of a quadruple circuit transmission line. It employs the Monte Carlo statistical technique to select lightning and system parameters and the dynamic travelling wave technique to calculate overvoltages on transmission line towers. The program has also incorporated nonlinear corona effects, the dynamic response of soil and the modelling of wooden-crossarms for arc-quenching in its calculations. The assessment of a Malaysian quadruple circuit dual voltage 275/132 kV transmission line using this program is demonstrated to illustrate the detailed nature of the analysis that is suitable for insulation design of transmission lines. >

The Statistical Computation of Line Performance Using METIFOR

A statistical analytical method has been developed for the insulation design of transmission lines. A computer program is described which computes flashover frequency based on a consideration of the statistics of insulation performance. The METIFOR digital weather model is incorporated as basic input to the program. Multisurface towers are considered, and optimum and minimum design dimensions are determined. The relative importance of design factors and insulation duties based on the results of METIFOR line design studies is discussed. Extension of the METIFOR weather model to include variables influencing contaminated perfornance is also described.