Abstract:With the increasingly complex structure of high-voltage power grids, the size of the ring network staggered situation is common, making the overall protection of the more complex calculation, especially the calculation of the value of the need to meet a variety of operating methods, and the calculation of the auxiliary increasing coefficient is very important in the calculation. In this paper, the characteristics of the existing high-voltage ring network, proposed a backtracking method of calculating the auxiliary increasing coefficient in ring network, through the protection of the ring circuit search can be different series of ring network, a comprehensive consideration of different series ring network of various harsh running and compared with the traditional calculation auxiliary increasing coefficient method. It is concluded that the backtracking algorithm can quickly and accurately find the auxiliary increasing coefficient of the more extreme operation. Finally, the effectiveness of the proposed method is verified by an example of the grid, and the complexity of the proposed method is analyzed, and the speediness of the proposed method is verified.