Development of an Ultracapacitor-Based Intermediate Energy Storage System

In recent years, a number of military applications intended to run from automotive power systems have been developed. Such applications can require pulsed power of several kilowatts at a voltage level of several kilovolts, characteristics that make it impossible to run from such a source. In these applications, an energy storage system can be used to reduce the peak power demand from the automotive batteries and to boost the working voltage to kilovolt levels. The ultracapacitor intermediate energy storage system (UCIS) has been designed to provide an interface between a 24 V, 600 A battery and a 10 kV, 25 kJ capacitor bank. During each of three cycles, the UCIS charges the capacitor bank to 10 kV in two seconds, at which time the load discharges the capacitor bank. This paper includes the development of the UCIS, including modeling results, and system design.