A Multi-objective Control Strategy of the Energy Storage System in Distribution Networks with a High Proportion of Renewable Energy

Abstract With the development of battery technology and power electronic technology, battery-based energy storage has been widely used in Peak Shaving and Valley Filling frequency and voltage regulation for the power system with a high proportion of renewable energy integration. However, the existing control strategies of the energy storage system (ESS) mostly take peak shaving and valley filling frequency and voltage regulation as a single control objective, causing the rest capacity of the energy storage in the single control working period to be wasted, which significantly reduces the utilization rate and economic benefits of energy storage. How to improve the utilization rate and economic benefits of the ESS while enhancing the support performance of ESS has not received much attention. This paper proposes a multi-objective control strategy of ESS to maximize energy storage’s benefit and ensure the distribution network’s safe and stable operation. First of all, this paper combines the auxiliary compensation benefits of the price system of distributed energy storage power stations and proposes a comprehensive index that comprehensively considers the economy of the ESS and the stable operation of the distribution network to support the evaluation needs of multi-objective control of energy storage. On this basis, this paper predetermines the multi-layer judgment logic for ESS operation control under different operating conditions, divides the ESS into different operating conditions according to the control objectives, and proposes a multi-objective control strategy based on variable droop coefficients. It effectively utilizes the idle capacity of the ESS and achieves an optimized control of energy storage that takes into account both technology and economy. The simulation verification based on the energy storage model built in Matlab/Simulink is conducted to validate the effectiveness of the proposed ESS multi-objective control strategy.