Consensus-based coordination of electric vehicle charging considering transformer hierarchy. (November 2018)

• Record Type: Journal Article
• Authors: Zou, Suli; Hiskens, Ian; Ma, Zhongjing
• Is Part Of: Control engineering practice. Volume 80(2018)
• Page Start: 138
• Page End: 145
• Publication Date: 2018-11
• Subjects: Electric vehicles -- Transformer limits -- Distributed protocol -- Efficient charging control -- Consensus -- Decentralized optimization -- Convergence; Automatic control -- Periodicals; 629.89
• DOI: 10.1016/j.conengprac.2018.08.018
• Languages: English
• ISSNs: 0967-0661

Abstract

Abstract: The paper considers the coordination of electric vehicle (EV) charging where the loading on the transformers that serve the distribution feeders is taken into account. A decentralized control method is designed such that self-interested EVs are motivated to achieve global benefits. The formulation has a hierarchical structure. At the lower level, each transformer broadcasts a price signal to the EVs that it supplies, and the EVs individually determine their optimal charging strategies. At the upper level, the communication network between transformers is described as a graph and a consensus algorithm among the transformers is used to obtain a group consensus price that reflects the system generation cost. Each transformer then establishes a price which is composed of the consensus price together with a contribution that accounts for its loading characteristic. An update algorithm is developed which converges in a few (typically around ten) iterations to the unique and efficient (socially optimal) solution. Highlights: A decentralized control strategy is developed for coordinating the charging of electric vehicles. The decentralized strategy converges in a few iterations to the unique and efficient (socially optimal) solution. The control strategy has a hierarchical structure that takes into account transformer losses and capacity limits.