Determining the internal resistance of a battery cell of a traction battery that is connected to a controllable motor/generator
First Claim
1. A method for determining the internal resistance of a battery cell of a battery, comprising:
- connecting the battery to a controllable motor/generator in such a way that a flow of energy takes place (i) from the battery to the motor/generator and (ii) from the motor/generator to the battery;
modulating a magnetic field-forming portion of the motor/generator by alternating the direction of flow of energy between the battery and the motor/generator, wherein the modulation of the magnetic field-forming portion of the motor/generator takes place when the motor/generator is in a no-load state;
determining a change in voltage at the battery cell and a change in the current flow through the battery cell during the modulation of the magnetic field-forming portion of the motor/generator; and
calculating the internal resistance of the battery cell as a quotient of the determined change in voltage and the determined change in the current flow.
1 Assignment
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Accused Products
Abstract
In a method and a device for determining the internal resistance of a battery cell of a battery, the battery is connected to a controllable motor/generator in such a way that a flow of energy can take place from the battery to the motor/generator or from the motor/generator to the battery, including the following steps: modulation of the magnetic field-forming portion of the motor/generator, determination of a change in voltage at the battery cell and of a change of the current flow through the battery cell during the modulation of the magnetic field-forming portion of the motor/generator, and calculation of the internal resistance of the battery cell as the quotient of the change in voltage and the change in current flow.
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Citations
7 Claims
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1. A method for determining the internal resistance of a battery cell of a battery, comprising:
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connecting the battery to a controllable motor/generator in such a way that a flow of energy takes place (i) from the battery to the motor/generator and (ii) from the motor/generator to the battery; modulating a magnetic field-forming portion of the motor/generator by alternating the direction of flow of energy between the battery and the motor/generator, wherein the modulation of the magnetic field-forming portion of the motor/generator takes place when the motor/generator is in a no-load state; determining a change in voltage at the battery cell and a change in the current flow through the battery cell during the modulation of the magnetic field-forming portion of the motor/generator; and calculating the internal resistance of the battery cell as a quotient of the determined change in voltage and the determined change in the current flow. - View Dependent Claims (2, 3, 4)
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5. A device for determining the internal resistance of a battery cell of a battery connected to a controllable motor/generator in such a way that a flow of energy takes place (i) from the battery to the motor/generator and (ii) from the motor/generator to the battery, the device comprising:
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a control unit for modulating a magnetic field-forming portion of the motor/generator by alternating the direction of flow of energy between the battery and the motor/generator, wherein the modulation of the magnetic field-forming portion of the motor/generator takes place when the motor/generator is in a no-load state; a measurement unit for determining a change in voltage at the battery cell and a change in the current flow through the battery cell during the modulation of the magnetic field-forming portion of the motor/generator; and a computing unit for calculating the internal resistance of the battery cell as a quotient of the determined change in voltage and the determined change in the current flow. - View Dependent Claims (6, 7)
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Specification