Decoupled linear AC power flow models with accurate estimation of voltage magnitude in transmission and distribution systems

Abstract Linearized power flow models are of great interest in power system studies such as contingency analyses and reliability assessments, especially for large-scale systems. One of the most popular models the classical DC power flow (DCPF) model is widely used and praised for its state-independence, robustness, and computational efficiency. Despite its advantages, however, the DCPF model fails to consider reactive power or bus voltage magnitude. This chapter proposes a decoupled linearized power flow (DLPF) model with respect to voltage magnitude and phase angle. The model is state-independent but is distinguished by its high accuracy in calculating voltage magnitude. Moreover, the chapter presents an in-depth analysis of the DLPF model with the purpose of accelerating its computation speed, leading to the fast DLPF model. Based on the general DLPF model, the linear three-phase power flow model is further developed for active distribution network with the consideration of ZIP load model and PV nodes. The linear sensitivity factors with regard to MW flow and bus voltage are also proposed as an application.