Calculation Method of 220kV Capacity-load Ratio of Regional Power Grid

The capacity-load ratio of 220kV regional power grid is an important index of power network planning. It is the basis for the macro-control of total substation capacity, power balance analysis, grid construction scale, and investment control. The value of the capacity-load ratio has a guiding significance for substation layout and capacity planning. In this paper, the sum of the annual on-grid electricity of the substation, the ratio of up-grid electricity to down-grid electricity, and the probability that the substation sends renewable energy or conventional power to the power grid are calculated. Then, the sum of up-grid and down-grid electricity of each 220kV substation in July and August in summer and January and December in winter are calculated and analyzed. At the same time, the ratio of the maximum up-grid power to the maximum down-grid power in the month is also calculated to judge whether it is larger or smaller than 1. The annual up-grid substation is obtained based on the power constraint, the ratio constraint of the maximum up-grid and down-grid power, and the probability constraint of the up-grid situation. Finally, the effectiveness and adaptability of the proposed method are verified by the operation data of a regional power grid.