Sensitivity Model-Based Optimal Decentralized Dispatching Strategy of Multi-Terminal DC Links for the Integration of Distributed Generations in Distribution Networks

Abstract

This study proposes a novel decentralized operation strategy for a multi-terminal direct current (MTDC) link system to control the power flow between interconnected distribution networks. The proposed strategy is divided into two stages. First, by applying a curve-/surface-fitting technique to the network topology data, the formulas for the voltage and total line losses in the network are derived. Subsequently, the active/reactive power set-points of the MTDC link are optimized to minimize the network losses and balance the injected power from the upstream grid. The optimization model with a quadratically constrained quadratic problem is relaxed as a second-order constrained programming model using the proposed substitution process. The proposed strategy is implemented solely based on the information at the point of common coupling of the MTDC link and does not require the acquisition of any real-time data related to the distributed generator output and load demand. The effectiveness of the proposed method is verified by comparing it with a conventional centralized operation method using modified IEEE-33 test networks.