Economic dispatching strategy of distributed energy storage for deferring substation expansion in the distribution network with distributed generation and electric vehicle

Aiming at the problem that the traditional substation expansion method leads to low availability of transformers and distributed generations (DG), and considering the improvement of energy storage operation revenue to reduce the energy storage investment cost, an energy storage economic dispatch strategy for deferring substation expansion is proposed. The strategy takes the charge-discharge balance as the criterion, considers the system security constraints and energy storage operation constraints, and aims at maximizing the comprehensive income of system loss and arbitrage from energy storage operation, and establishes the economic operation model of energy storage, the energy storage power is calculated according to different peak-cutting values, and the operating income of corresponding energy storage power is calculated by substituting it into the economic operation model. Finally, the energy storage power corresponding to the optimal income is determined. Through the simulation and analysis of the IEEE33 bus distribution system, based on the proposed evaluation index, the results show that the economic dispatching strategy proposed in this paper can greatly increase the operating income of energy storage, reduce the equivalent annual investment cost of energy storage equipment by $54,930 compared with the substation expansion scheme, and increase the annual availability rate of transformers to 32.8%, the annual availability hours of distributed generations increased by 267 h. (C) 2020 Elsevier Ltd. All rights reserved.