Method and System to Measure Series-Connected Cell Voltages Using a Flying Capacitor
AssigneeEnerdel, Inc.
InventorsRonald H. Jaegar, Chad Hartzog
Life of this patent
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Abstract
A method and system for measuring voltage of individual cells connected in series includes a pair of busses connectable to the cells and a flying capacitor connectable to the busses. The capacitor stores the charge of one of the cells such that an analog-to-digital converter (ADC) connected to the capacitor may process an accurate representation of the voltage of the cell being measured. In order to prevent electrical interference with the capacitor and the ADC, the charge on the busses is reduced prior to measurement by the ADC
Claims10
A method of measuring voltage of individual cells in a plurality of cells connected in series, said method comprising:
- electrically connecting one of the cells to a capacitor via a plurality of busses disposed between the cells and the capacitor;
- charging the capacitor for a predetermined charge time;
- electrically disconnecting the capacitor from the busses in response to an elapse of the predetermined charge time;
- and
- reducing the charge on the busses in response to the electrical disconnection of the capacitor from the busses.
A system for measuring voltage of individual cells in a plurality of cells connected in series, said system comprising:
- a plurality of cell switches for electrical connection to the plurality of cells wherein each cell switch includes a first side and a second side with said first side of each cell switch electrically connectable to a positive terminal of one of the cells;
- a first bus electrically connected to said second side of every other cell switch;
- a second bus electrically connected to said second side of each cell switch not connected to said first bus;
- a capacitor for storing a charge of at least one of the cells wherein said capacitor includes a pair of terminals;
- a first bus switch electrically connected between said first bus and said capacitor for connecting at least one of the cells to said capacitor;
- a second bus switch electrically connected between said second bus and said capacitor for connecting at least one of the cells to said capacitor;
- and
- a first bus ground switch electrically connected between said first bus and ground and a second bus ground switch electrically connected between said second bus and ground.
Dependencies are inferred from the claim text.