A Multi-Stage Planning Method for Coordinating Energy Storage and Transmission Network Considering the Flexibility of Line Transmission

Renewable energy sources exhibit significant volatility and uncertainty, and their large-scale integration into the grid exacerbates the flexibility issues of the power system. This is primarily due to the insufficient supply of flexible resources and the limitations on line power transmission. Furthermore, there is currently limited research on the flexibility of line transmission. To address this, a multi-stage planning method for coordinating energy storage and transmission network considering the flexibility of line transmission is proposed. Initially, the line flexibility load rate is defined to evaluate the flexibility of line transmission. This flexibility is then incorporated into the constraints, and the Conditional Value at Risk (CVaR) theory is applied to measure the operational risk of excessive line flexibility load rates. Consequently, a comprehensive bi-level, multi-stage planning model is established, taking into account both investment costs and operational costs. Validation through an actual system in a province in Northwest China demonstrates that the proposed method can effectively enhance the economic and flexible operation of the power system.