Induction motor analysis and control method
AssigneeRockwell Automation Technologies, Inc.
InventorsWei Qian, Haihui Lu, Thomas A. Nondahl
Life of this patent
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Abstract
An induction motor controller that may include three phase paths leading from a power input to a power output, a solid-state switching device interposed between the power input and the power output on each of the three phase paths, a voltage sensor coupled to two of the phase paths between the solid-state switching device and the power input, a current sensor on one of the phase paths, a processor communicatively coupled to the voltage sensor, the current sensor, and the solid state switching device; and a memory coupled to the processor. The processor may be configured to calculate a motor parameter based on a signal from the voltage sensor and a signal from the current sensor and store the calculated motor parameter in memory.
Claims19
A method, comprising:
- sensing a phase-to-phase voltage of a power supply;
- sensing a current in at least one phase of the power supply;
- closing a switch at a desired phase angle of the power supply;
- determining both motor resistance and motor inductance of an induction motor based upon the sensed voltage and the sensed current;
- and
- exercising in-situ feedback control of an induction motor based on the determined motor resistance and motor inductance.
A method, comprising:
- sensing a phase-to-phase voltage of a power supply;
- sensing a current in at least one phase of the power supply;
- energizing a gate of an SCR at a predetermined time before the power supply voltage reaches zero volts;
- and
- determining both motor resistance and motor inductance of an induction motor based upon the sensed voltage and the sensed current.
A method, comprising:
- sensing a phase-to-phase voltage of a power supply;
- sensing a current in at least one phase of the power supply;
- energizing a gate of an SCR at a desired phase angle before the power supply voltage reaches zero volts;
- sampling a transient response of an induction motor coupled to the power supply;
- and
- determining both motor resistance and motor inductance of the induction motor based upon the sensed voltage and the sensed current.
Dependencies are inferred from the claim text.