Comparison between centralized and decentralized storage energy management for Direct Wave Energy Converter Farm

This article compares the sizes of an Energy Storage System (ESS) with two control types in order to smooth a Direct Wave Energy Converter (DWEC) Farm Production, namely a centralized one that deals with the PCC power and a decentralized one that deals with each unit power production. The main objective is to compare the two controls on the basis of their life cycle cost. The SEAREV project is the Direct Wave Energy Converter used as an example in this paper. The ESS is necessary for grid integration in the case considered here due to the flicker constraint, which is not being satisfied without storage. The optimization strategies for both the sizing and the management of an Energy Storage System (ESS) will be described: the rule-based energy management approach depends on the State of Energy of this ESS as well as the power produced by the DWEC unit or the DWEC farm. This management strategy has been optimized for each size in order to reduce aging speed while strictly respecting the flicker criterion. The final design is expected to minimize total system cost. The centralized control clearly allowed smaller capacity, but has some drawbacks for the losses in the rest of the farm.