Research On Influence Of Large Current For Smart Grid Substation

Substation is the hub of the power system, substation lightning will result in significant damage to electrical equipment. It would cause blackouts and seriously affect China's economic development and people's life. As the rapid development of smart grid substation, there will be a large number of secondary equipment into the substation such as measurement, control, wireless transmission, and large current caused by lightning would be a serious threat to the stable operation of these devices. So how to improve the reliability of protection of substation high current caused by lightning has become an urgent problem.Protection of substation high current caused by lightning is a systematic project, not only direct lightning effective protection, but also for lightning surge protection along the road to the invasion and considers the MOA residual voltage generated by the impact of low-voltage power system. The paper analyzes three aspects of this study and proposed the corresponding lightning protection program. First the paper analyzed the production process of large current lightning and parameters of lightning current, and obtain the most realistic model of the large current.Secondly, under different operation using the ATP program to model a 220kV substation in order to obtain over-voltage amplitude of significant electrical equipment when the substation get struck by lighting. Through analysis and comparison of simulation results, proposed an economical and reliable protection of 220kV substation. Finally, using the principle of low-voltage power system consists of more surge protectors can enhance the reliability of lightning surge protection, the paper put forward a multi-grade surge protection for secondary system in substation and using electromagnetic transient program (EMTP) analysis the performance of protection. Through analysis and comparison of simulation results can be obtained its protection performance fully meet the requirements of the reliability of protection. For the entire substation, when they work together at the same time, the reliability of substation lightning protection can be guaranteed.