Decentralized Optimization of Transmission and Distribution System with Wind-Photovoltaic-Hydro Coordination

Abstract

The large fluctuation of wind and photovoltaic (PV) power generation leads to the problem of insufficient stability and reliability when it is connected to the power grid. It is an important method to use the complementary characteristics of wind, PV and hydro power generation to stabilize the fluctuation of its total output. This paper studies the coordinated optimal operation of wind, PV and hydro resources, and proposes a co-optimization model of wind, PV and hydro resources under the coordination of transmission and distribution network. In order to protect the privacy of transmission network and distribution network, and reduce the computational burden of dispatching center, a decentralized solution strategy based on alternating direction method of multipliers (ADMM) is introduced to solve the proposed model. In addition, to ensure the convergence of the decentralized algorithm, the second-order cone relaxation method is used to transform the power flow model of distribution network into a convex optimization model. The results show that the wind, PV and hydro coordinated optimization and the cooperation between transmission network and distribution network can effectively reduce the overall power fluctuation and promote the renewable energy consumption. The accuracy and convergence of the proposed decentralized algorithm are also verified.