Rotor position estimator for an electrical machine
AssigneeRockwell Automation Technologies, Inc.
InventorsJingbo Liu, Thomas Nondahl, Peter B. Schmidt, Semyon Royak, Mark M. Harbaugh
Life of this patent
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Abstract
A method for estimating a rotor position in an electrical machine is provided. The method is applicable to electrical machines that have magnetic saliency. The method includes extracting the rotor position from a demodulated output signal generated in response to an injected high frequency carrier signal and determining a position error compensation based upon a demodulation delay and a velocity or rotational frequency of the electrical machine. The method also includes estimating the rotor position by applying the position error compensation to the extracted rotor position.
Claims20
A method for estimating a rotor position in an electrical machine, comprising:
- extracting the rotor position from a demodulated output signal generated in response to an injected high frequency carrier signal;
- determining a position error compensation based upon a demodulation delay and a velocity or rotational frequency of the electrical machine;
- and
- estimating the rotor position by applying the position error compensation to the extracted rotor position.
A rotor position estimator for an electrical machine, comprising:
- a motor drive configured to produce a high frequency carrier signal and to inject the signal into the electrical machine;
- a demodulator configured to process an output signal generated in response to the injected high frequency carrier signal and to extract a rotor position from the output signal;
- a position error compensator configured to determine a position error compensation based upon a demodulation delay of the demodulator and a velocity or rotational frequency of the electrical machine and to apply the position error compensation to the extracted rotor position.
A motor drive system, comprising:
- an electrical machine having a stator and a rotor;
- an inverter configured to provide power to the electrical machine and to inject a high frequency carrier signal into the electrical machine;
- a demodulator configured to process an output signal generated in response to the injected high frequency carrier signal and to extract a rotor position from the output signal;
- a position error compensator configured to determine a position error compensation based upon a demodulation delay of the demodulator and a velocity or rotational frequency of the electrical machine.
Dependencies are inferred from the claim text.