Method and device for ascertaining the rotor temperature of a permanent-magnet synchronous machine
AssigneeRobert Bosch GmbH
InventorsUlrich Vollmer, Matthias Bitzer
Life of this patent
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Abstract
A method for ascertaining the rotor temperature of a permanent-magnet synchronous machine (10), in which a first estimate (TR1) for the rotor temperature is ascertained as a function of a remanent flux density of permanent magnets contained in a rotor of the synchronous machine (10). A second estimate (TR2) for the rotor temperature is ascertained via a Kalman filter containing a thermal model of the synchronous machine (10), the first estimate (TR1) for the rotor temperature being supplied at least intermittently to the Kalman filter.
Claims17
A method for ascertaining the rotor temperature of a permanent-magnet synchronous machine comprising:
- determining a first estimate (TR1) for the rotor temperature as a function of a remanent flux density of permanent magnets contained in a rotor of the synchronous machine, and determining a second estimate (TR2) of the rotor temperature by using a Kalman filter containing a thermal model of the synchronous machine, the first estimate (TR1) for the rotor temperature being supplied to the Kalman filter at least intermittently;
- wherein the first estimate (TR1) for the rotor temperature and a measured value (TS) for stator temperature are both supplied to the Kalman filter for a correction step;
- and
- wherein a steady-state model of the synchronous machine is used for determining the first estimate (TR1), for the rotor temperature according to:
- Ud=R·Id−Lq·Iq·ω
- Uq=R·Iq+Ld−Id·ω+Km·ω
- where Ud, Uq denote the voltage of synchronous machine in the d direction and q direction, respectively, Id, Iq denote the current of the synchronous machine in the d direction and q direction, respectively, and Ld, Lq denote the corresponding inductances, where R is a strand resistance, ω is the electrical angular velocity and Km is a temperature-dependent fundamental-wave amplitude of the field-linked direct-axis flux.
A method for ascertaining the rotor temperature of a permanent-magnet synchronous machine comprising:
- determining a first estimate (TR1) for the rotor temperature as a function of a remanent flux density of permanent magnets contained in a rotor of the synchronous machine, and determining a second estimate (TR2) of the rotor temperature by using a Kalman filter containing a thermal model of the synchronous machine, the first estimate (TR1) for the rotor temperature being supplied to the Kalman filter at least intermittently;
- wherein either only the first estimate (TR1) for the rotor temperature or a measured value (TS) for stator temperature is supplied to the Kalman filter for a correction step;
- and
- wherein a steady-state model of the synchronous machine is used for determining the first estimate (TR1), for the rotor temperature according to:
- Ud=R·Id−Lq·Iq·ω
- Uq=R·Iq+Ld−Id·ω+Km·ω
- where Ud, Uq denote the voltage of the synchronous machine in the d direction and q direction, respectively, Id, Iq denote the current of the synchronous machine in the d direction and q direction, respectively, and Ld, Lq denote the corresponding inductances, where R is a strand resistance, ω is the electrical angular velocity and Km is a temperature-dependent fundamental-wave amplitude of the field-linked direct-axis flux.
A device for determining the rotor temperature of a permanent-magnet synchronous machine, the device being capable of determining a first estimate (TR1) for the rotor temperature as a function of a remanent flux density of permanent magnets contained in a rotor of the synchronous machine, and the device being capable of determining a second estimate (TR2) for the rotor temperature via a Kalman filter containing a thermal model of the synchronous machine, the first estimate (TR1) for the rotor temperature being supplied at least intermittently to the Kalman filter;
- and
- wherein the first estimate (TR1) for the rotor temperature and a measured value (TS) for stator temperature are both supplied to the Kalman filter for a correction step;
- wherein a steady-state model of the synchronous machine is used for determining the first estimate (TR1), for the rotor temperature according to:
- Ud=R·Id−Lq·Iq·ω
- Uq=R·Iq+Ld−Id·ω+Km·ω
- where Ud, Uq denote the voltage of the synchronous machine in the d direction and q direction, respectively, Id, Iq denote the current of the synchronous machine in the d direction and q direction, respectively, and Ld, Lq denote the corresponding inductances, where R is a strand resistance, ω is the electrical angular velocity and Km is a temperature-dependent fundamental-wave amplitude of the field-linked direct-axis flux.
A device for determining the rotor temperature of a permanent-magnet synchronous machine, the device being capable of determining a first estimate (TR1) for the rotor temperature as a function of a remanent flux density of permanent magnets contained in a rotor of the synchronous machine, and the device being capable of determining a second estimate (TR2) for the rotor temperature via a Kalman filter containing a thermal model of the synchronous machine, the first estimate (TR1) for the rotor temperature being supplied at least intermittently to the Kalman filter, wherein either only the first estimate (TR1) for the rotor temperature or a measured value (TS) for stator temperature is supplied to the Kalman filter for a correction step;
- wherein a steady-state model of the synchronous machine is used for determining the first estimate (TR1), for the rotor temperature according to:
- Ud=R·Id−Lq·Iq·ω
- Uq=R·Iq+Ld−Id·ω+Km·ω
- where Ud, Uq denote the voltage of the synchronous machine in the d direction and q direction, respectively, Id, Iq denote the current of the synchronous machine in the d direction and q direction, respectively, and Ld, Lq denote the corresponding inductances, where R is a strand resistance, ω is the electrical angular velocity and Km is a temperature-dependent fundamental-wave amplitude of the field-linked direct-axis flux.
Dependencies are inferred from the claim text.