Optimal power flow considering transient thermal behavior of overhead transmission lines

Abstract Electrothermal coordination (ETC) is a concept which exploits the potential transfer capability of transmission lines by coordinating the transient thermal behavior of the conductor and the system control actions. For the realization of ETC decision, the model of optimal power flow considering transient thermal behavior (OPFCTTB) of overhead lines and the solution methods are proposed in this paper. The OPFCTTB model is established by introducing the heat balance equations (HBEs) of overhead lines as equality constraints and the temperature of lines as the decision variable into the ac optimal power flow model. To solve the OPFCTTB model whose constraints consist of nonlinear differential-algebraic equations, the model is first discretized into a dynamic optimization problem whose constraints are algebraic equations, and then the primal-dual interior point method (PDIPM) is utilized to solve the discretized model. To improve the solution efficiency, the large-scale correction equations of the Karush-Kuhn-Tucker conditions in PDIPM are decoupled into several small-scale groups which can be solved in parallel. Numerical simulations on benchmark systems verify the validity of the proposed OPFCTTB model and corresponding solution methods.