Electricity: battery or capacitor charging or discharging – Battery or cell charging – Pulsed
Patent
1997-01-29
1998-06-16
Wong, Peter S.
Electricity: battery or capacitor charging or discharging
Battery or cell charging
Pulsed
320119, H02J 704
Patent
active
057676607
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention concerns a method for charging and/or charge exchange between a plurality of like energy storage devices connected in series where at least one electric storage device is, in timed fashion, connected in parallel to the energy storage devices, wherein each electric storage device is a transformer component charged from the energy storage devices, and concerns additionally an apparatus for the application of the method.
Such a monitoring method is known from U.S. Pat. No. -A-4 331 911 and serves the equalization of voltages of individual series-connected accumulators with a DC--DC converter. The sole central converter for all accumulators is charged from the overall battery and is unable to detect peculiarities of individual accumulators resulting from ageing.
Until the deterioration of such an accumulator in its storing and charging quality is recognized by the monitoring device for accumulators, its malfunction leads to a chain of reactions in the group of the accumulators, which also results in a degradation of the other accumulators.
DE-PS 30 31 931 describes a device for extending the discharge time of rechargeable accumulators where the states of charge of the accumulators are detected with a monitoring device. A longer, reliable discharge of the accumulators is accomplished in that the accumulator operation is not terminated upon discharge of the weakest cell, and thus arrival at a limit voltage, but only when this limit voltage is reached at the average of all interconnected accumulators. A service life extension of accumulators in view of their replacement cannot be achieved thereby.
Known from SU 1 065 959 is a device for an accumulator charger that prevents overcharging and charging at inverted polarity of accumulators. The charging current is monitored by a transistor circuit which additionally comprises zener diodes. This safety circuit, however, can guarantee neither a monitoring of the quality of the accumulators nor bring about a longer service life of accumulators degrading in their quality.
Known from Applicant's EP 90 123 409 is a monitoring device for a plurality of series-wired like accumulators wherein with the aid of a control circuit an electric storage device is connected in parallel to one of the accumulators, wherein the primary winding of a transformer, in series with a breaker connected to the control circuit, is connected in parallel to the poles of the group of accumulators, The electric storage device is always formed of the secondary winding, which is always connected via a blocking diode to each accumulator. As a difference signal occurs in the control circuit, a function generator is, via a comparator, circuit turned on between the accumulators, the output of which generator is connected to the breaker. This makes it possible to supply energy to exactly the weakest accumulator. For small applications, this system has the disadvantage of a plurality of control components representing a cost factor and, as the case may be, a space and weight factor. Besides the appreciable expense for selecting the respective weak or strong cell, the performance range of the blocking converters used is upwardly limited.
All of these devices have the drawback that charging the energy storage devices, which may be, e.g., battery banks of an electric vehicle, requires an external charger which, in turn, occupies space in such a vehicle and represents additional weight.
SUMMARY OF THE INVENTION
In view of this prior art, the objective underlying the invention is to provide a method of the initially mentioned type wherein, besides delaying the replacement of an accumulator degraded in its quality at low wiring expense, the charging of the energy storage devices can also be effected.
This objective is inventionally met for a method in that the at least one electric storage device is switched in the charging operation, in one timing step, as secondary winding, with a feeder winding arranged on the same core being provided as primary winding, and in that
REFERENCES:
patent: 4331911 (1982-05-01), Park
patent: 5003244 (1991-03-01), Davis, Jr.
patent: 5633575 (1997-05-01), Gali
patent: 5646504 (1997-07-01), Feldstein
Hung, Stephen T., "Entension of Battery Life via Charge Equalization Cont," IEEE Transactions on Industrial Electrontics, vol. 4, No. 1, Feb. 1993, pp. 96-104, Apr. 30,1992.
Fraunhofer-Gesellschaft Zur Forderung der Angewandten Forschung
Toatley , Jr. Gregory J.
Wong Peter S.
LandOfFree
Method and apparatus for charging and/or charge exchange between does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for charging and/or charge exchange between, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for charging and/or charge exchange between will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1729795