Enhancing the power grid flexibility with battery energy storage transportation and transmission switching

Abstract

Abstract The penetration of large-scale renewable energy puts an urgent demand on increasing power grid flexibility. From the power grid perspective, transmission congestion has become one of the bottle-neck factors limiting renewable energy integration. In the tradition, transmission topology is regarded to be unadjustable, and energy storage only plays an important role in the local area where it locates. To enhance the transmission system flexibility and relieve transmission congestion, this paper proposes a network-constraint unit commitment (NCUC) model considering battery energy storage transportation (BEST) and transmission switching (TS). This model is integrated with a novel indicator based BEST model and a TS model to minimize the overall operating cost. The benefits of BEST mobility and TS flexibility are quantitatively evaluated through compared with the traditional NCUC model. Based on the difference between the overall operating cost of unit commitment (UC) and NCUC, we quantitatively evaluated the flexibility provided by BEST and TS by the overall operating cost reduction. A case study on a modified IEEE RTS-79 system is provided to validate the effectiveness of the proposed model. The results show that the BEST and TS have a synergistic effect on enhancing power grid flexibility, which reflects in this study as the power grid operating economics improvement and renewable energy curtailment reduction. Besides, though the BEST and TS bring transmission system more losses, applying them into the system could relieve transmission congestion, which makes them valuable technologies to improve power system security.