Equalizer system and method for series connected energy storing devices

Patent · Fri Jan 01 00:00:00 EST 1999

OSTI ID:872518

Rouillard, Jean ^[1]; Comte, Christophe ^[2]; Hagen, Ronald A ^[3]; Knudson, Orlin B ^[4]; Morin, Andre ^[5]; Ross, Guy ^[6]

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1. Saint-Luc, CA
2. Montreal, CA
3. Stillwater, MN
4. Vadnais Heights, MN
5. Longueuil, CA
6. Beloeil, CA

An apparatus and method for regulating the charge voltage of a number of electrochemical cells connected in series is disclosed. Equalization circuitry is provided to control the amount of charge current supplied to individual electrochemical cells included within the series string of electrochemical cells without interrupting the flow of charge current through the series string. The equalization circuitry balances the potential of each of the electrochemical cells to within a pre-determined voltage setpoint tolerance during charging, and, if necessary, prior to initiating charging. Equalization of cell potentials may be effected toward the end of a charge cycle or throughout the charge cycle. Overcharge protection is also provided for each of the electrochemical cells coupled to the series connection. During a discharge mode of operation in accordance with one embodiment, the equalization circuitry is substantially non-conductive with respect to the flow of discharge current from the series string of electrochemical cells. In accordance with another embodiment, equalization of the series string of cells is effected during a discharge cycle.

• Research Organization: United States Advanced Battery Consortium, Dearborn, MI (US)
• DOE Contract Number: FC02-91CE50336
• Assignee: Minnesota Mining & Manufacturing Co. (St. Paul, MN); Hydro-Quebec Corporation (Montreal, CA)
• Patent Number(s): US 5952815
• OSTI ID: 872518
• Country of Publication: United States
• Language: English

Related Subjects

equalizer
method
series
connected
energy
storing
devices
apparatus
regulating
charge
voltage
electrochemical
cells
disclosed
equalization
circuitry
provided
control
amount
current
supplied
individual
included
string
interrupting
flow
balances
potential
pre-determined
setpoint
tolerance
charging
prior
initiating
cell
potentials
effected
cycle
throughout
overcharge
protection
coupled
connection
discharge
mode
operation
accordance
embodiment
substantially
non-conductive
respect
series string
discharge current
storing device
series connected
electrochemical cells
electrochemical cell
energy storing
series connection
overcharge protection
charge cycle
charge voltage
storing devices
connected energy
current supplied
discharge cycle
cells connected
charge current
cell potential
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