ANALYSIS OF APPROACHES FOR ESTIMATING THE LIGHTNING PERFORMANCE OF OVERHEAD TRANSMISSION LINES

Abstract

Purpose. A review of the current literature, regarding the existing approaches used to estimate the lightning perfor-mance of overhead power lines, was performed. A review of available lightning activity data over India was also per-formed. Methodology. The electro-geometrical model was chosen to analyze the lightning performance of overhead power lines. International normative documents and national standard were used to highlight the main parameters that should to be paid main attention to when estimating lightning performance of overhead power lines. Results. Presently, approaches from IEEE and CIGRE guides can be used for analysis of statistical distributions of lightning current pa-rameters. Further studies are required on thunderstorm days, ground flash density and current parameters statistical dis-tributions for different locations, which will be supportive in performing analysis for Indian power lines. Originality. To graphically analyze the shielding failure mechanism with a help of electro-geometric model, the sketch of real 220 kV double-circuit transmission line tower was used. Using electro-geometric model it was graphically shown how downward lightning leader that propagate from thunderstorm cloud toward ground can finish its path on the overhead shield wire, phase conductor or ground plane. Practical value. Available data on lightning activity over different parts of India are still not enough complete. It is of great importance to obtain reliable statistical data on thunderstorm characteristics in the area of the studied power line route. Measurement techniques based on satellites have limitations in obtaining ground flash density values. Thus, for India there is a need in development of modern lightning detection networks and related studies on lightning characteristics. Conclusions. Future efforts should be focused on obtaining not only the positions and number of lightning strikes to the overhead power line, and calculation of lightning flashover rate parameters, but also the statistical distributions of lightning current values and related overvoltage parameters at the overhead wires and different phase conductors. References 21, figures 4.