Capacity planning method and system of HPFC device

The invention discloses a capacity planning method and system for an HPFC device, and the method comprises the steps: building a secondary evaluation index system which is used for evaluating the improvement capability of the access of the HPFC device to the comprehensive stability characteristic of a power grid in advance; and according to the evaluation value of each alternative scheme corresponding to the secondary evaluation index system and the evaluation values of the positive ideal scheme and the negative ideal scheme corresponding to the alternative scheme, obtaining the relative closeness between each alternative scheme and the positive ideal scheme, and selecting the alternative scheme corresponding to the maximum value of the relative closeness as a final capacity planning scheme. The secondary evaluation index system fully quantifies the influence of the HPFC device on the static and dynamic comprehensive stability characteristics of the power grid from three aspects of the steady-state power flow