Transmission and distribution coordination in power systems with high shares of distributed energy resources providing balancing and congestion management services

摘要

This paper presents a literature review on the coordination between transmissionand distribution grid operators in power systems, with particular emphasis on theprovision of balancing and congestion management services. Firstly, a brief historicalbackground is presented in order to highlight the ongoing changes currentpower systems are experiencing and that call for greater coordination betweentransmission system operators (TSO) and distribution system operators (DSO).These include the growth in distributed energy resources (DER), new roles to beadopted by both system operators (SO), and the integration of new agents such asindependent aggregators. Next, the paper places its focus on a particular topicwhich, based on the review presented, is presumably considered as the most relevantissue requiring tighter cooperation mechanisms, that is, the procurement ofbalancing services from DER by TSOs whilst DSOs procures the same DER flexibilityto manage local congestions. Four key elements are identified for this coordinationto take place, namely (a) DER flexibility integration, (b) coordinationschemes, (c) transmission-distribution optimization, and (d) data exchange. Foreach one of them, the paper presents a literature review and identifies the mainexisting technical, economic, and regulatory barriers. These barriers include,among others, the limitation for small DER flexibility to participate in grid servicemarkets, the challenges for independent aggregators, the technical barriers for optimizinga transmission-distribution grid, and the lack of maturity in coordinationschemes and TSO-DSO data exchange models.