Current measurement using a di/dt current sensor
OwnerChristopher Thomas Brown, Jonathan Ephraim David Hurwitzinventors
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Abstract
The present disclosure relates to a current measurement system and method that uses a rate of change of current sensor, such as a Rogowski Coil. The system comprises a rate of change of current sensor and a coupled measurement circuit. A temperature response of at least part of the signal processing circuitry is set so as to reduce or eliminate changes in the signal gain of the system caused by temperature changes.
Claims20
A method of setting a temperature response of a current measurement system, wherein the current measurement system comprises:
- a current sensing coil for sensing a current in a conductor;
- and signal processing circuitry coupled to the current sensing coil for determining a measurement of the current in the conductor, the method comprising:
- setting a temperature response of at least part of the signal processing circuitry based on at least one of:
- an impedance of the current sensing coil;
- an input impedance of the signal processing circuitry to which the current sensing coil is coupled;
- or
- a temperature dependent signal gain of the current measurement system.
A current measurement system comprising:
- a current sensing coil comprising an opening suitable for a conductor to pass through, wherein the coil is suitable for sensing current in the conductor passing through the opening;
- and
- signal processing circuitry coupled to the current sensing coil for determining a measurement of the current,
- wherein the signal processing circuitry is configured for setting a temperature response of at least part of the signal processing circuitry based on at least one of:
- an impedance of the current sensing coil;
- an input impedance of the signal processing circuitry to which the current sensing coil is coupled;
- or
- a temperature dependency of a signal gain of the current measurement system.
Signal processing circuitry for use in measuring a current using a current sensing coil, the signal processing circuitry comprising:
- one or more input terminals for coupling to a current sensing coil;
- an analog to digital converter, ADC, for digitally converting an analog signal that is dependent on a signal at the one or more input terminals;
- and
- a reference voltage circuit coupled to the ADC so as to supply a reference voltage to the ADC,
- wherein the reference voltage circuit is configured to be trimable across a predetermined range of values so as to trim the reference voltage supplied to the ADC and set a temperature response of the signal processing circuitry, wherein the predetermined range of values is set to support a range of current sensing coil impedances.
Dependencies are inferred from the claim text.