Reduced stack voltage circuitry for energy storage system diagnostics
AssigneesBallard Power Systems Inc., Simon Fraser University
InventorsJacob W. Devaal, Hooman Homayouni, Farid Golnaraghi
Life of this patent
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Abstract
Systems and methods to provide a low voltage interface coupleable between an energy storage device or a DC power source (e.g., fuel cell stack, battery) and one or more AC signal diagnostic systems. The low voltage interface reduces a voltage of the DC power source and supplies the reduced voltage to the one or more AC signal diagnostic systems without affecting the results of the measurements obtained by the one or more AC signal diagnostic systems. Such functionality provides a safer method for performing advanced analysis (e.g., EIS, frequency analysis) while utilizing lower cost and/or smaller components.
Claims32
A low voltage interface which in use couples a direct current (DC) power source to an alternating current (AC) signal diagnostic system, the DC power source comprises a positive node, the AC signal diagnostic system comprises a diagnostic signal output node which applies an AC signal to the DC power source, the AC signal diagnostic system further comprises a measurement input node, the low voltage interface comprising:
- an interface input node electrically coupleable to the positive node of the DC power source;
- a first interface output node electrically coupleable to the measurement input node of the AC signal diagnostic system;
- and
- a voltage-reduction circuit electrically coupled to the interface input node and the first interface output node, the voltage-reduction circuit:
- receives an input voltage from the DC power source via the interface input node, the input voltage comprising a DC component and an AC component;
- reduces the DC component of the input voltage without substantially affecting a magnitude or phase of the AC component of the input voltage, or reduces the DC component of the input voltage with a constant amplification or a constant phase shift of the AC component of the input voltage, which provides a measurement voltage including, a reduced DC component;
- and
- provides the measurement voltage to the measurement input node of the AC signal diagnostic system via the first interface output node.
A direct current (DC) power system, comprising:
- a DC power source comprising a positive node;
- alternating current (AC) signal diagnostic system comprising a diagnostic signal output node which applies an AC signal to the DC power source, the AC signal diagnostic system further comprising a measurement input node;
- and
- a low voltage interface comprising:
- an interface input node electrically coupled to the positive node of the DC power source;
- a first interface output node electrically coupled to the measurement input node of the AC signal diagnostic system;
- and
- a voltage-reduction circuit electrically coupled to the interface input node and the first interface output node, the voltage-reduction circuit:
- receives an input voltage from the DC power source via the interface input node, the input voltage comprising a DC component and an AC component;
- reduces the DC component of the input voltage without substantially affecting a magnitude or phase of the AC component of the input voltage, or reduces the DC component of the input voltage with a constant amplification or constant phase shift of the AC component of the input voltage, which provides a measurement voltage including a reduced DC component;
- and
- provides the measurement voltage to the measurement input node of the AC signal diagnostic system via the first interface output node.
A method, comprising:
- receiving an input voltage at an interface input node of a low voltage interface electrically coupled to a positive node of a direct current (DC) power source, the input voltage comprising a DC component and an AC component;
- reducing the DC component of the input voltage without substantially affecting a magnitude or phase of the AC component of the input voltage, or reducing the DC component of the input voltage with a constant amplification or constant phase shift of the AC component of the input voltage, to generate a measurement voltage including a reduced DC component;
- and
- providing the measurement voltage to a measurement input node of an AC signal diagnostic system via a first interface output node electrically coupled to a measurement input node of the AC signal diagnostic system, the AC signal diagnostic system comprising a diagnostic signal output node which in use applies an AC signal to the DC power source.
A low voltage interface, comprising:
- an interface input node electrically coupleable to a positive node of a DC power source;
- a first interface output node electrically coupleable to a measurement input node of an AC signal diagnostic system that includes a diagnostic signal output node that applies an AC signal to the DC power source;
- and
- a voltage-reduction circuit electrically coupled to the interface input node and the first interface output node and including a VBE multiplier circuit electrically coupled in series with a biasing current source, the voltage-reduction circuit:
- receives an input voltage from the DC power source via the interface input node, the input voltage comprising a DC component and an AC component;
- reduces the DC component of the input voltage without substantially affecting a magnitude or phase of the AC component of the input voltage, or reduces the DC component of the input voltage with a constant amplification or a constant phase shift of the AC component of the input voltage, which provides a measurement voltage;
- and
- provides the measurement voltage to the measurement input node of the AC signal diagnostic system via the first interface output node.
Dependencies are inferred from the claim text.