Control and Co-ordination of Flexibilities for Active Network Management in Smart Grids : Li-ion BESS Fast Charging Case

Abstract

Fast charging of Lithium-ion battery energy storage systems (Li-ion BESSs) when utilized in the medium voltage (MV) distribution networks may introduce its own stress on the network under certain operating modes, especially when combined with intermittent renewable power generation. In such situations, active network management (ANM) schemes by managing available flexibilities in the MV network is a possible solution to maintain operation limits defined by grid codes. The studies in this paper are related to the utilization ANM schemes for MV distribution network in Sundom Smart Grid, Vaasa, Finland. The aim of this study is to capture the stresses induced by fast charging of Li-ion BESSs during low wind power generation and utilization of ANM schemes to mitigate those arising issues. The effect of such ANM schemes on integration of Li-ion BESS, i.e. control of its grid-side converter (considering operation states and characteristics of the Li-ion BESS) and their coordination with the grid side controllers to enforce network ANM schemes have been analyzed in detail. Particularly, the effect of AC load on the DC characteristics of Li-ion BESSs has been evaluated in this simulation study.