System for calculating remaining capacity of energy storage device
First Claim
1. A system for calculating the remaining capacity of an energy storage device, the system comprising:
- voltage detection means for detecting the terminal voltage of the energy storage device;
current detection means for detecting the charge and discharge current of the energy storage device;
first calculation means for integrating the charge and discharge current detected by the current detection means to calculate a first remaining capacity;
second calculation means for estimating the open circuit voltage of the energy storage device on the basis of the terminal voltage detected by the voltage detection means, the charge and discharge current detected by the current detection means, and the impedance of the equivalent circuit of the energy storage device to calculate a second remaining capacity based on the estimated open circuit voltage; and
third calculation means for weighting the first and second remaining capacities with a weight determined depending on the operating conditions of the energy storage device and combining the weighted remaining capacities into the remaining capacity of the energy storage device.
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Accused Products
Abstract
The remaining capacity of a battery obtained by integrating current and that obtained from the estimated open circuit voltage of the battery are weighted with a weight which varies depending on the operating conditions of the battery as needed and the weighted remaining capacities are combined into the final remaining capacity. Thus, the disadvantages of the remaining capacity based on current integration and those of the remaining capacity based on the estimated open circuit voltage cancel each other out and the advantages of the respective remaining capacities can be fully utilized. The uniform calculation accuracy can be ensured and the final remaining capacity can always be obtained with accuracy.
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Citations
16 Claims
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1. A system for calculating the remaining capacity of an energy storage device, the system comprising:
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voltage detection means for detecting the terminal voltage of the energy storage device;
current detection means for detecting the charge and discharge current of the energy storage device;
first calculation means for integrating the charge and discharge current detected by the current detection means to calculate a first remaining capacity;
second calculation means for estimating the open circuit voltage of the energy storage device on the basis of the terminal voltage detected by the voltage detection means, the charge and discharge current detected by the current detection means, and the impedance of the equivalent circuit of the energy storage device to calculate a second remaining capacity based on the estimated open circuit voltage; and
third calculation means for weighting the first and second remaining capacities with a weight determined depending on the operating conditions of the energy storage device and combining the weighted remaining capacities into the remaining capacity of the energy storage device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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Specification