Electricity: battery or capacitor charging or discharging – Serially connected batteries or cells – With discharge of cells or batteries
Patent
1996-12-23
1998-10-13
Wong, Peter S.
Electricity: battery or capacitor charging or discharging
Serially connected batteries or cells
With discharge of cells or batteries
320 17, H01M 1044, H01M 1046
Patent
active
058217290
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention concerns a method for charge exchange between a plurality of like energy storage devices or energy converters connected in series so that at least one electric storage device is, at a given rate, connected in parallel to the energy storage devices or energy converters, and wherein each electric storage device is a transformer component charged by the energy storage devices or energy converters, and concerns additionally a device for the application of the method.
Such a monitoring method is known from U.S. Pat. No. 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 by 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 ability is recognized by the monitoring device for accumulators, its malfunction leads to a chain reaction 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 EP 90 123 409 of the applicant is a monitoring device for a plurality of series-wired like accumulators where with the aid of a control circuit an electrical 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 formed always of the secondary winding, which always is 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.
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 where the replacement of an accumulator degraded in its quality can be delayed at reduced wiring expense as compared to the prior art.
According to the invention, this objective is met by connecting the transformer components at the stated timing rate in parallel to one of the like energy storage devices or energy converters, so that all like energy storage devices or energy converters are, in at least one timing step, connected in parallel, each individually, to a transistor component in the same winding sense.
Opening and closing at a switching frequency, e.g., in the kilohertz range, the breakers form together with the transformer a transformer co
REFERENCES:
patent: 4331911 (1982-05-01), Park
patent: 4479083 (1984-10-01), Sullivan
patent: 5177425 (1993-01-01), Goto
patent: 5528122 (1996-06-01), Sullivan
patent: 5594320 (1997-01-01), Pacholok et al.
patent: 5646504 (1997-07-01), Feldstein
Switched Capacitor System for Automatic Series Battery Equalization by Php T. Krein and Cesar Pascual; APEC '97 Twelfth Annual Applied Power Electronics Conference and Exposition, vol. 2, pp. 848-855.
Jantsch Martin
Schmidt Heribert
Fraunhofer-Gesellschaft Zur Forderung der Angewandten Forschung
Law Patrick B.
Wong Peter S.
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