Economic dispatch of interconnected networks considering hidden flexibility

Abstract

—Owing to privacy concerns, data sharing between interconnected power networks is not always possible. Data sharing hinders cooperation among internal and external networks. Existing equivalence-based models can protect privacy and represent external characteristics. However, these models can be used only for a single-period economic dispatch, ignoring the hidden flexibility of the external network, especially the ramping flexibility. This paper proposes a multiperiod economic dispatch model considering the hidden flexibility. The hidden flexibility subjected to the operational constraints of the external network is represented by the proposed equivalent flexibility model. In this model, the operational constraints, including power balance equations, transmission capacity limits, and generation capacity limits, are equivalent to the feasible regions of tie lines based on multiparametric programming. To further capture the hidden ramping flexibility, equivalent ramping constraints are proposed, which are formulated as piecewise functions with respect to the tie line power. Based on the equivalent flexibility model, the multiperiod economic dispatch model of the interconnected power networks is constructed, which is a mixed integer linear programing (MILP) problem. A heuristic method is proposed to reduce the computational burden. The effectiveness of the proposed method is demonstrated by test systems.