Gini Coefficient for Voltage Security Assessment of Multi-stage Transmission Expansion Planning

Abstract

Due to the voltage security uncertainty caused by construction sequence in multi-stage transmission expansion planning (MTEP) in bulk power grids, it is necessary to appropriately arrange the construction sequence of the MTEP schemes to reduce voltage security risk. The Gini coefficient is widely used to weigh the gap of residents' income distribution. In this paper, the voltage security Gini coefficient is defined as the voltage security risk index of the MTEP scheme, and is presented to quantitatively evaluate the entire voltage security of one MTEP scheme. Voltage security evaluation model of the MTEP is established based on voltage security Gini coefficient. Compared to the stabilization cost, the proposed model directly reflects the voltage security of the MTEP scheme, and the local optimum is avoided. The presented method is applied on the IEEE 118-bus 54-generator test system. Results show the validity and effectiveness of the proposed model.