Design of hybrid energy storage system using dual batteries for renewable applications

Battery systems are mainly designed in terms of charge/discharge power and energy capacity. Hybrid Battery Energy Storage Systems (HBESS) which are made of several kinds of batteries can reduce system volume and cost. In this paper, power and energy management algorithms and costs estimation method for HBESS are described. The validity of the algorithms is confirmed by simulations using charge/discharge power demand waveforms of a wind farm. By using this algorithm, it is estimated that in some cases up to 36% of battery cost can be reduced, compared to single-type BESS. Furthermore, the algorithms are demonstrated on a test 200kW system in our laboratory consisting of two kinds of lithium-ion battery: high power type for hybrid vehicles, and high energy type for stationary applications.