Characteristics of Ground Wire Currents along Transmission Line under Lightning Strikes

Harvesting power from ground wires is an emergent method to solve the power supply issues of online monitoring units in the overhead transmission lines. However, the power harvesting device based on ground wire has a much higher probability to be exposed to lightning overvoltage or overcurrent. Therefore, this paper studies ground wire impulse current characteristics under various lightning strike situations to guide the design of protection module in the power harvesting device based on ground wire. Furthermore, a spectrum analysis is also conducted to study the refraction and reflection in the ground wire. Meanwhile, this paper discusses the influence of lightning impulse current waveform, span and impulse resistance of tower grounding device in the ground wire current.