Abstract: The paper proposes a health index theory based on provincial grid operation data regarding the current operational status of the power grid system.Based on the importance of ensuring energy supply,starting from the two dimensions of safety and reliability and the importance of energy supply, the paper proposes five indexes including load transfer rate, equipment fault ratio, reclosing success rate, fault recovery time, and fault voltage level coefficient. In order to ensure the reasonableness of index weight calculation, the subjective weight, objective weight and comprehensive weight are obtained by game theory method. By analyzing and calculating the tripping data of 14 municipalities in Hunan, the health index levels of different municipalities are given. Finally, the paper measures the health index level of the grid in a local city throughout the year and analyzes the correlation between its health index changes and weather, and provides guidance suggestions for the actual operation of the grid.

Key words: health index, game theory approach, provincial grid, energy supply security, system operation