Energy storage unit
First Claim
1. An energy storage unit comprising:
- two or more storage elements (2. 2′
) which are switched in series;
a charge redistribution circuit (6, 6′
), which is installed in such a manner that a voltage of the storage element (UELn, UELn′
) is measured and is compared with a voltage threshold value (UTHRn, UTHR,UTHRn′
, UTHR′
), wherein the charge redistribution circuit (6, 6′
) removes charge when the voltage threshold value (UTHRn, UTHR, UTHRn, ′
, UTHR′
), is exceeded by a storage element (2, 2′
) from said storage element (2, 2′
), thus reducing its voltage (UELn, UELn′
), and a storage related temperature determination is conducted and the voltage threshold value (UTHRn, UTHR,UTHRn′
, UTHR′
) is set variably in dependence on the determined temperature (Tn, T), so that as the temperature (Tn, T) increases, the voltage threshold value (UTHRn, UTHR, UTHRn′
, UTHR′
) is reduced; and
wherein the energy storage unit is for a motor vehicle which is equipped with an electric drive or an electric hybrid drive, wherein the voltage threshold value (UTHR, UTHR, UTHRn′
, UTHR′
) is also set variably in dependence on the current operating state of the vehicle, in such a manner that the threshold value (UTHRn, UTHR, UTHRn′
, UTHR′
) is set higher for relatively brief periods of time when the storage or removal requirement is relatively high.
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Accused Products
Abstract
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.
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Citations
10 Claims
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1. An energy storage unit comprising:
-
two or more storage elements (2. 2′
) which are switched in series;a charge redistribution circuit (6, 6′
), which is installed in such a manner that a voltage of the storage element (UELn, UELn′
) is measured and is compared with a voltage threshold value (UTHRn, UTHR,UTHRn′
, UTHR′
), wherein the charge redistribution circuit (6, 6′
) removes charge when the voltage threshold value (UTHRn, UTHR, UTHRn, ′
, UTHR′
), is exceeded by a storage element (2, 2′
) from said storage element (2, 2′
), thus reducing its voltage (UELn, UELn′
), and a storage related temperature determination is conducted and the voltage threshold value (UTHRn, UTHR,UTHRn′
, UTHR′
) is set variably in dependence on the determined temperature (Tn, T), so that as the temperature (Tn, T) increases, the voltage threshold value (UTHRn, UTHR, UTHRn′
, UTHR′
) is reduced; andwherein the energy storage unit is for a motor vehicle which is equipped with an electric drive or an electric hybrid drive, wherein the voltage threshold value (UTHR, UTHR, UTHRn′
, UTHR′
) is also set variably in dependence on the current operating state of the vehicle, in such a manner that the threshold value (UTHRn, UTHR, UTHRn′
, UTHR′
) is set higher for relatively brief periods of time when the storage or removal requirement is relatively high. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 10)
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9. An energy storage unit for a vehicle which is equipped with an electric drive or an electric hybrid drive, the energy storage unit comprising:
-
two or more storage elements (2, 2′
) which are switched in series; anda charge redistribution circuit (6,6′
), which is installed so that a voltage of the storage element (UELn, UELn′
) is measured and is compared with a voltage threshold value (UTHRn, UTHR, UTHRn′
, UTHR′
), wherein when the voltage threshold value (UTHRn, UTHR, UTHRn′
, UTHR′
) is exceeded by a storage element (2, 2′
), the charge redistribution circuit (6) removes charge from said storage element (2, 2′
) thus reducing its voltage (UELn, UELn′
), and wherein the voltage threshold value (UTHRn, UTHR, UTHRn′
, UTHR′
) is set variably in dependence the current operating state of the vehicle in such a manner that the threshold value (UTHRn, UTHR, UTHRn′
, UTHR′
) is set higher for relatively brief periods of time when the storage or removal requirement is relatively high;wherein the dependence on the current operating state of the vehicle is one or more of the following dependencies; while the vehicle is in operation, the threshold value (UTHRn, UTHR, UTHRn′
, UTHR′
) is higher at standstill;during operation with a frequently changing driving state, the threshold value (UTHRn, UTHR, UTHRn′
, UTHR′
) is higher than during operation with a more uniform driving state; andduring electrical regenerative braking and afterwards, the threshold value (UTHRn, UTHR, UTHRn′
, UTHR′
) is higher than when no electrical regenerative braking occurs.
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Specification