Method and system for estimating voltage of a battery element

摘要

A method for estimating the voltage of a battery element of a battery system is provided. In one embodiment, the method comprises providing a balancing/sensing circuit having a series combination of a balancing switch and a balancing resistive element electrically connected in parallel with the battery element, and measuring the voltage across the balancing switch/balancing resistive element combination when the switch is presumed to be in a “closed” state.” The method further comprises deriving a compensated value for the measured voltage by applying a calculated compensation factor to the measured voltage, the compensated value compensating for a voltage drop occurring in the balancing/sensing circuit when the balancing switch is in the “closed” state and represents an estimate of the battery element voltage. A battery system is also provided that includes a battery element, a balancing/sensing circuit, a sensor, and a control module configured to perform the method described above.

主权项

1. A method for estimating the voltage of a battery element of a vehicle battery system, the method comprising the steps of:
providing a balancing/sensing circuit having a series resistive element and a series combination of a balancing switch and a balancing resistive element electrically connected in parallel with the battery element; measuring the voltage across the combination of the balancing switch and balancing resistive element when the balancing switch is presumed to be in a “closed” state; and deriving a compensated value for the measured voltage by applying a calculated compensation factor to the measured voltage, wherein the compensated value compensates for a voltage drop associated with the series resistive element that occurs in the balancing/sensing circuit when the balancing switch is in the “closed” state and the compensated value represents an estimate of the actual voltage of the battery element, and further wherein the calculated compensation factor is derived from measurement(s) of one or more electrical parameters relating to the balancing/sensing circuit.