Control system for a sensor-free electric motor
AssigneeInfineon Technologies AG
InventorsMartin Barth, Qifan Yang
Life of this patent
Estimating the term…
Abstract
A method with which stalling of a rotor of a sensor-free motor can be detected is described below. According to one exemplary embodiment, the method comprises operating an electric motor, wherein a rotation speed of the electric motor is controlled by field-oriented control, and wherein an estimate is calculated, wherein the estimate represents magnetic flux in the electric motor. The method further comprises calculating a value which represents the change in the magnitude of the estimate for the magnetic flux and comparing the calculated value with a threshold value in order to detect whether the calculated value lies below the threshold value. An error is flagged if it is detected that the calculated value lies below the threshold value for a specific time.
Claims10
A method comprising:
- operating an electric motor, wherein a rotation speed of the electric motor is controlled by field-oriented control, wherein an estimate is calculated, wherein the estimate represents a magnetic flux in the electric motor,
- calculating a value which represents a change in magnitude of the estimate for the magnetic flux based on a first magnitude of the estimate for the magnetic flux at a first time step and a second magnitude of the estimate for the magnetic flux at a second time step that is different from the first time step;
- comparing the calculated value with a threshold value in order to detect whether the calculated value is below the threshold value;
- and
- flagging an error in response to detecting that the calculated value is below the threshold value for a specific time.
A system comprising:
- an electric motor;
- a control arrangement which is coupled to the electric motor and is designed to drive the electric motor and to control rotation speed of the electric motor by field-oriented control;
- wherein the control arrangement is further designed to:
- calculate an estimate which represents magnetic flux in the electric motor,
- calculate a value which represents a change in magnitude of the estimate for the magnetic flux based on a first magnitude of the estimate for the magnetic flux at a first time step and a second magnitude of the estimate for the magnetic flux at a second time step that is different from the first time step;
- and
- compare the calculated value with a threshold value in order to detect whether the calculated value is below the threshold value and to flag an error in response to detecting that the calculated value is below the threshold value for a specific time.
An integrated circuit comprising:
- a circuit arrangement which is designed to carry out field-oriented control for a synchronous motor, wherein the circuit arrangement includes a flux estimator which is designed to calculate an estimate for a magnetic flux in the synchronous motor;
- and
- a detector circuit which is designed to detect stalling of a rotor of the synchronous motor, wherein, to detect stalling of the rotor, the detector circuit is configured to:
- calculate a value which represents a change in magnitude of the estimate for the magnetic based on a first magnitude of the estimate for the magnetic flux at a first time step and a second magnitude of the estimate for the magnetic flux at a second time step that is different from the first time step flux,
- compare the calculated value with a threshold value in order to detect whether the calculated value is below the threshold value, and
- determine that the rotor has stalled if the calculated value is below the threshold value for a specific time.
Dependencies are inferred from the claim text.