| 摘要 |
In an energy storage system that includes a battery and an ultracapacitor, the state of charge (SOC) of the capacitor is the subject of a dynamic set-point. This dynamic set-point control is a function of the load regime to which the storage system is exposed, for example a hybrid automobile or electric automobile. The control may be based in part upon real-time fast Fourier transform analysis of load current, permitting real-time adjustment of control coefficients. In this way, it is possible to minimize the occurrence of the capacitor being fully charged at a time when it would be desired to be able to absorb high current, for example from regenerative braking. Likewise it is possible to minimize the occurrence of the capacitor being nearly discharged at a time when it would be desirable to have boost power available. A result is that even a relatively small ultracapacitor (having perhaps one two- hundredth the energy storage capacity of the battery) can permit greatly reducing waste heat dissipated in the battery, and can reduce otherwise unnecessary cycling of current into and out of the battery. This can extend battery life and battery performance. |
