Equalizer system and method for series connected energy storing devices
US5952815A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jul 25, 1997 |
| Grant date | Sep 14, 1999 |
| Priority date | — |
| Expiry date | Jul 25, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02J7/0048
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.