A Non-Iterative Decoupled Solution of the Coordinated Robust OPF in Transmission and Distribution Networks With Variable Generating Units

Robust optimal power flow (OPF) deals with extreme scenarios of uncertainty associated with the high penetration of renewable energy resources. The development of active distribution networks allows transmission and distribution networks to become coupled, which brings about a critical need for a coordinated solution of robust OPF. However, a centralized solution of the robust OPF is difficult to implement for the entire transmission and distribution networks because the two networks are operated by different operators. We propose a non-iterative decoupled method for the coordinated solution of the robust OPF in transmission and distribution networks. The optimal generation cost of a distribution network is converted to a piecewise quadratic function of the boundary transferred power, so that the solution of the coordinated robust OPF can be simplified to a piecewise quadratic program. An efficient descent direction search method is proposed to deal with the piecewise quadratic program and a linearization method is developed to accelerate the proposed solution process. Numerical tests are performed on few power systems to demonstrate that the proposed non-iterative method can obtain a sufficiently accurate solution, which is also more efficient than other traditional decentralized methods.