Modeling and Simulation of Lightning Strike Effects on Extra High Voltage Transmission Lines

Abstract

This study presents a detailed modeling and simulation analysis of how lightning strikes impact Extra High Voltage (EHV) transmission lines, using MATLAB simulation. A comprehensive transient simulation framework was developed to illustrates the electromagnetic effects of direct lightning strikes, with a focus on how surges travel along conductors, trigger insulation breakdowns, initiate faults, and influences system recovery. One notable finding is that a direct lightning strike with a peak current of 40 kA can generate an overvoltage of up to 1550 kV at the point of impact far exceeding the Basic Insulation Level of 1050 kV which leads to immediate insulation flashover and fault initiation. In such events, the fault current was observed to peak at 12.3 kA, with arc extinction occurring within 5.7 ms and voltage recovering in about 19.4 ms. Line surge arresters played a crucial role in absorbing excess energy, dissipating up to 1.47 MJ during a strike, thus mitigating potential equipment damage. The system’s protection mechanisms, including coordinated relay and circuit breaker actions, were able to isolate the fault within 68 ms, effectively maintaining system stability. These results demonstrate the importance of robust lightning protection strategies such as selecting appropriate surge arresters and optimizing grounding systems to enhance the resilience of EHV transmission lines. The proposed simulation model provides a valuable tool for utilities seeking to evaluate lightning vulnerabilities and strengthen protection coordination in high-voltage networks.