Method and device for estimating individual phase resistance of an electric motor
AssigneeDanfoss Power Electronics A/S
InventorsJens Godbersen, Lucian Asiminoaei
Life of this patent
Estimating the term…
Abstract
The present invention relates to a method for estimating individual phase resistance of a motor by means of an adjustable speed drive (ASD) while the motor controlled by the ASD is running and/or is at standstill. The motor is an asynchronous motor or a synchronous motor. The invention also relates to an adjustable speed drive for executing a corresponding method.
Claims19
A method for estimating individual phase resistance of a motor by means of an adjustable speed drive (ASD), while the motor controlled by the ASD is running and/or is at standstill, wherein the motor is an asynchronous motor or a synchronous motor, the method comprising the steps of:
- injecting at least two DC currents in the motor as an ASD output,
- determining the output voltages and currents resulting from injecting the DC currents,
- extracting DC components present in the determined output voltages and currents, and
- calculating the cumulated output resistance Rs seen by the ASD on each phase of the motor individually,
- wherein the injected DC currents are synchronized with different phase angles of a fundamental output current of the ASD.
A method for estimating individual phase resistance of a motor by means of an adjustable speed drive (ASD), while the motor controlled by the ASD is running and/or is at standstill, wherein the motor is an asynchronous motor or a synchronous motor, the method comprising the steps of:
- injecting at least two DC currents in the motor as an ASD output,
- determining the output voltages and currents resulting from injecting the DC currents,
- extracting DC components present in the determined output voltages and currents, and
- calculating the cumulated output resistance Rs seen by the ASD on each phase of the motor individually,
- wherein the DC currents are injected in a discontinues manner, for a limited injection period followed by a waiting period until next DC current injection.
A method for estimating individual phase resistance of a motor by means of an adjustable speed drive (ASD), while the motor controlled by the ASD is running and/or is at standstill, wherein the motor is an asynchronous motor or a synchronous motor, the method comprising the steps of:
- injecting at least two DC currents in the motor as an ASD output,
- determining the output voltages and currents resulting from injecting the DC currents,
- extracting DC components present in the determined output voltages and currents, and
- calculating the cumulated output resistance Rs seen by the ASD on each phase of the motor individually,
- wherein the calculated resistances Rs on each phase are fed back into the ASD and used for updating the ASD references, control parameters and/or control settings.
Dependencies are inferred from the claim text.