Battery energy management proposition for energy storage using active dc–dc converter

Abstract

Battery energy storage systems (BESS) are storage facilities used for ancillary services, mainly to support renewable sources operation that can reach megawatts of power. As a consequence, battery packs must be associated, and power electronics are necessary to control power flow. As a consequence, battery packs must be associated, and power electronics are necessary to control power flow, among the different design alternatives for building a BESS. This paper offers an alternative for a BESS based on a new control strategy applied to a two-stage bidirectional dc-dc converter. The proposed strategy is capable of setting the power flow through voltage/current control during operation based on real-time battery conditions, extending system life (using optimum dispatchable energy) and increasing reliability and profitability. In addition, State-of-Charge and State-of-Health are monitored, in order to keep track of aging effects. Moreover, the strategy enables mixing different battery technologies with a wide range of degradation, which can be used to retrofit operational plants or even build new systems focused on second life batteries.Simulation studies are performed using Typhoon HIL604, and a prototype is presented to validate the effectiveness of the methodology of the proposed control strategy.