摘要 |
An energy storage unit has several storage elements (2, 2′) which are switched in series and a charge redistribution circuit (6, 6′). The latter is installed in such a manner that the voltage of the storage element (UELn, UEln′) is measured and compared with a voltage threshold value (UTHRn, UTHR, UTHRn′, UTHR′). When the threshold value is exceeded by a storage element, it removes charge from said storage element, thus reducing its voltage. According to one aspect, a storage-related temperature determination is conducted, and the threshold value is set variably in dependence on the determined temperature (Tn, T) in such a manner that it is reduced as the temperature increases. According to a further aspect, the threshold value is set variably in dependence on the current vehicle operating state, in such a manner that it is set higher for relatively brief periods of time when the storage or removal requirement is relatively high. According to an additional further aspect, the threshold value is set lower for storage elements with a relatively advanced age than for those with a less advanced age. |