Lightning protection safety operation assessment method of UHV AC substation based on probability theory of power system operation mode

Abstract

International standard IEEE P1862-2014, IEEE recommended practices for over-voltage and insulation coordination of transmission system at 1000kV AC and above, and Chinese national standard GB/Z24842-2018, over-voltage and insulation coordination of 1000kV UHVAC power transmission and transformation project, clearly stipulates that the probability of general operation mode and special operation mode should be considered when predicting over-voltage. However, how to reflect the probability of the above operation mode in the lightning protection safety evaluation index of UHV AC substation, the above standards did not give a clear quantitative method. In this paper, on the basis of the above specifications and considering the probability of power system operation mode, the lightning protection safety assessment method of UHV AC substation was comprehensively and deeply studied. Firstly, the probability statistics of general operation mode and special operation mode of UHVAC transmission system were carried out. The concept of probability coefficient was put forward for the first time, and the value of probability coefficient was suggested. Then, the lightning protection safety assessment method of UHV AC substation under general operation mode and special operation mode based on probability coefficient was proposed. Finally, the lightning protection safety evaluation standard of UHV AC substation was given. The research results can further improve the scientificity of lightning protection safety assessment of UHV AC substation, and have radiation effect and reference significance for lightning protection safety assessment of UHV AC substation.