Position estimation method for self-sensing electric machines based on the direct measurement of the current slope

Tuomas Haarnoja, Teemu Halmeaho, Aino Manninen, Kari Tammi

    Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

    Abstract

    In self-sensing machines, the rotor displacement or angle is recovered from the wave form of the winding current simplifying thus the structure and lowering the price of the machine. This paper introduces a new technique to enable sensorless operation of a magnetic bearing or other self-sensing Pulse-Width Modulation (PWM)-fed electric machines. The approach is based on the measurement of the rate of change of the winding current at the PWM frequency. The current slope along with the current and voltage measurements is used for estimating the winding inductance, which is a dynamic function of the rotor displacement and angle. The rotor state can then be deduced by matching the estimated inductance to the inductance model. The concept is tested in a setup in which the rotor of a Switched Reluctance Machine is levitated against the gravity using feedback from a displacement sensor. The actual displacement is then compared to the estimate given by the self-sensing algorithm. The estimate is found to be accurate, but sensitive to modeling error.
    Original languageEnglish
    Title of host publicationProceedings
    Subtitle of host publication7th IET International Conference on Power Electronics, Machines and Drives, PEMD 2014
    PublisherInstitution of Engineering and Technology IET
    Number of pages6
    ISBN (Electronic)978-1-84919-815-8
    DOIs
    Publication statusPublished - 2014
    MoE publication typeA4 Article in a conference publication
    Event7th IET International Conference on Power Electronics, Machines and Drives, PEMD 2014 - Manchester, United Kingdom
    Duration: 8 Apr 201410 Apr 2014

    Conference

    Conference7th IET International Conference on Power Electronics, Machines and Drives, PEMD 2014
    Abbreviated titlePEMD 2014
    CountryUnited Kingdom
    CityManchester
    Period8/04/1410/04/14

    Fingerprint

    Electric machinery
    Rotors
    Inductance
    Pulse width modulation
    Magnetic bearings
    Voltage measurement
    Electric current measurement
    Gravitation
    Feedback
    Sensors

    Keywords

    • voltage measurement
    • machine control
    • reluctance machines
    • rotors
    • magnetic bearings
    • electric current measurement

    Cite this

    Haarnoja, T., Halmeaho, T., Manninen, A., & Tammi, K. (2014). Position estimation method for self-sensing electric machines based on the direct measurement of the current slope. In Proceedings: 7th IET International Conference on Power Electronics, Machines and Drives, PEMD 2014 Institution of Engineering and Technology IET. https://doi.org/10.1049/cp.2014.0391
    Haarnoja, Tuomas ; Halmeaho, Teemu ; Manninen, Aino ; Tammi, Kari. / Position estimation method for self-sensing electric machines based on the direct measurement of the current slope. Proceedings: 7th IET International Conference on Power Electronics, Machines and Drives, PEMD 2014. Institution of Engineering and Technology IET, 2014.
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    title = "Position estimation method for self-sensing electric machines based on the direct measurement of the current slope",
    abstract = "In self-sensing machines, the rotor displacement or angle is recovered from the wave form of the winding current simplifying thus the structure and lowering the price of the machine. This paper introduces a new technique to enable sensorless operation of a magnetic bearing or other self-sensing Pulse-Width Modulation (PWM)-fed electric machines. The approach is based on the measurement of the rate of change of the winding current at the PWM frequency. The current slope along with the current and voltage measurements is used for estimating the winding inductance, which is a dynamic function of the rotor displacement and angle. The rotor state can then be deduced by matching the estimated inductance to the inductance model. The concept is tested in a setup in which the rotor of a Switched Reluctance Machine is levitated against the gravity using feedback from a displacement sensor. The actual displacement is then compared to the estimate given by the self-sensing algorithm. The estimate is found to be accurate, but sensitive to modeling error.",
    keywords = "voltage measurement, machine control, reluctance machines, rotors, magnetic bearings, electric current measurement",
    author = "Tuomas Haarnoja and Teemu Halmeaho and Aino Manninen and Kari Tammi",
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    Haarnoja, T, Halmeaho, T, Manninen, A & Tammi, K 2014, Position estimation method for self-sensing electric machines based on the direct measurement of the current slope. in Proceedings: 7th IET International Conference on Power Electronics, Machines and Drives, PEMD 2014. Institution of Engineering and Technology IET, 7th IET International Conference on Power Electronics, Machines and Drives, PEMD 2014, Manchester, United Kingdom, 8/04/14. https://doi.org/10.1049/cp.2014.0391

    Position estimation method for self-sensing electric machines based on the direct measurement of the current slope. / Haarnoja, Tuomas; Halmeaho, Teemu; Manninen, Aino; Tammi, Kari.

    Proceedings: 7th IET International Conference on Power Electronics, Machines and Drives, PEMD 2014. Institution of Engineering and Technology IET, 2014.

    Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

    TY - GEN

    T1 - Position estimation method for self-sensing electric machines based on the direct measurement of the current slope

    AU - Haarnoja, Tuomas

    AU - Halmeaho, Teemu

    AU - Manninen, Aino

    AU - Tammi, Kari

    N1 - Project code: 78632

    PY - 2014

    Y1 - 2014

    N2 - In self-sensing machines, the rotor displacement or angle is recovered from the wave form of the winding current simplifying thus the structure and lowering the price of the machine. This paper introduces a new technique to enable sensorless operation of a magnetic bearing or other self-sensing Pulse-Width Modulation (PWM)-fed electric machines. The approach is based on the measurement of the rate of change of the winding current at the PWM frequency. The current slope along with the current and voltage measurements is used for estimating the winding inductance, which is a dynamic function of the rotor displacement and angle. The rotor state can then be deduced by matching the estimated inductance to the inductance model. The concept is tested in a setup in which the rotor of a Switched Reluctance Machine is levitated against the gravity using feedback from a displacement sensor. The actual displacement is then compared to the estimate given by the self-sensing algorithm. The estimate is found to be accurate, but sensitive to modeling error.

    AB - In self-sensing machines, the rotor displacement or angle is recovered from the wave form of the winding current simplifying thus the structure and lowering the price of the machine. This paper introduces a new technique to enable sensorless operation of a magnetic bearing or other self-sensing Pulse-Width Modulation (PWM)-fed electric machines. The approach is based on the measurement of the rate of change of the winding current at the PWM frequency. The current slope along with the current and voltage measurements is used for estimating the winding inductance, which is a dynamic function of the rotor displacement and angle. The rotor state can then be deduced by matching the estimated inductance to the inductance model. The concept is tested in a setup in which the rotor of a Switched Reluctance Machine is levitated against the gravity using feedback from a displacement sensor. The actual displacement is then compared to the estimate given by the self-sensing algorithm. The estimate is found to be accurate, but sensitive to modeling error.

    KW - voltage measurement

    KW - machine control

    KW - reluctance machines

    KW - rotors

    KW - magnetic bearings

    KW - electric current measurement

    U2 - 10.1049/cp.2014.0391

    DO - 10.1049/cp.2014.0391

    M3 - Conference article in proceedings

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    PB - Institution of Engineering and Technology IET

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    Haarnoja T, Halmeaho T, Manninen A, Tammi K. Position estimation method for self-sensing electric machines based on the direct measurement of the current slope. In Proceedings: 7th IET International Conference on Power Electronics, Machines and Drives, PEMD 2014. Institution of Engineering and Technology IET. 2014 https://doi.org/10.1049/cp.2014.0391