A four-terminal interconnected topology and its application in distribution network expansion planning

Abstract

It is a huge challenge for traditional distribution networks (DNs) topologies to tackle the large-scale integration of renewable energy because of insufficient flexibility. This paper proposes a four-terminal interconnected topology (FTIT) for DNs, which has a variety of flexible operation modes and greatly increases the accommodation capacity of renewable energy. A bi-level DN expansion planning method is proposed, which can make full use of the topological flexibility of FTIT to balance the economy, reliability, environmental benefits and renewable energy accommodation level of expansion planning schemes on the premise of meeting the secure operation of DNs. A 69-bus real DN is used to test the proposed method. The simulation results show that the proposed FTIT and planning method can flexibly adjust power flow distribution under different renewable energy penetration to promote the accommodation of renewable energy and to reduce the annual comprehensive cost of the DN.