Abstract:
To address the issues of low energy storage utilization and poor economic efficiency on the power generation side, a centralized energy storage sharing structure for the power generation side and a hierarchical control strategy are proposed, including new batteries and retired batteries. Firstly, design a centralized energy storage resource sharing structure for renewable energy station clusters that considers differences in health status, and respond to the power needs of multiple stations through aggregated control methods. Secondly, by analyzing the performance differences between new and old batteries, the maximum available capacity is used to represent the state of health(SOH), and the state of charge(SOC) is used to calculate the available charge and discharge margin in real time. The energy storage units’ output ranking rule is formulated, and a hierarchical control strategy for the battery energy storage units considering SOH and available charge and discharge margin is proposed. Finally, a case study shows that a hybrid configuration of new and old batteries can reduce investment costs. The proposed control strategy can reduce the number of actions of new and old battery units to 53.68% and 20.79%, respectively, and the total number of charge and discharge state transitions to 14.29%, while maintaining good energy storage regulation capability continuously.