Equivalent series resistance-based real-time control for a battery-ultracapacitor hybrid system

This paper provides an equivalent series resistance-based real-time control method for the battery-ultracapacitor hybrid system. The idea of this control method is that the dynamic load demand is distributed based on the equivalent series resistance ratio of batteries to ultracapacitors, whilst the estimated average load demand based on the past N seconds is supplied by the batteries. In addition, the energy stored in the ultracapacitors is considered for protection purpose. The simulation results verify the effectiveness of the equivalent series resistance-based real-time control method, in terms of the system efficiency, the overall energy loss, and the utilization of the ultracapacitors. Further comparison results show that the efficiency of the proposed real-time control method with well-selected parameter is only 1% lower than that of the dynamic programming method.