Research on Transient Electromagnetic Stress of 10-kV Electrical Equipment in the Substation Under Lightning Strikes

The 10-kV distribution power system is vulnerable to the lightning strikes. It is essential to deeply analyze the transient electromagnetic process of the electrical equipment under lightning impulse and propose effective methods to mitigate the transient stress of the equipment to ensure the safety of the power system. Firstly, this paper built a simulation model based on the actual electrical topology and equipment parameters of a 110 kV/35 kV/10 kV substation, and then calculated the transient overvoltage and overcurrent under direct and induced lightning strikes, which would be up to several hundreds of kV and tens of kA. Next, three lightning protection measures were analyzed and their protection effect were compared. Reducing the grounding resistance of towers and optimizing the configuration of surge arresters in substation can effectively reduce the energy stress of the surge arresters. The installation of the overhead ground wire can reduce the probability of direct lightning strikes on phase lines and reduce the peak of induced lightning overvoltage by more than 20%.