US7868581B2
Active / In Force
US
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Induction motor analysis and control method
Assignee: Rockwell Automation Technologies Inc
•
Filing: 2008-02-28
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Granted: 2011-01-11
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Expires: 2028-02-28
Abstract
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.
Inventors
- 👤 Wei Qian
- 👤 Haihui Lu
- 👤 Thomas A. Nondahl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 00:01
CPC Classifications
H; H02; H02P; H02P23/00; H02P23/14; H02P27/00; H02P27/04; H02P27/16; Y; Y10; Y10S; Y10S388/00; Y10S388/907; Y10S388/917
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
73 words
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.
Claim 2
Independent Claim
73 words
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.
Claim 3
Dependent Claim
29 words
The method of claim 1 , wherein closing the switch comprises energizing a gate of an SCR at a predetermined time before a power supply voltage reaches zero volts.
Claim 4
Dependent Claim
22 words
The method of claim 1 , wherein determining comprises sampling a transient response of the induction motor with a digital signal processor.
Claim 5
Dependent Claim
32 words
The method of claim 1 , wherein determining comprises calculating an inductance and resistance with a least square algorithm, a least mean square algorithm, a maximum likelihood algorithm, or a combination thereof.
Claim 6
Dependent Claim
19 words
The method of claim 1 , comprising storing a determined inductance value and a determined resistance value in memory.
Claim 7
Dependent Claim
20 words
The method of claim 1 , comprising calculating a temperature of an induction motor based on the determined resistance value.
Claim 8
Dependent Claim
35 words
The method of claim 1 , comprising: closing the switch a second time; determining an inductance, resistance, or both a second time; and calculating another motor parameter based on the result of both determining steps.
Claim 9
Independent Claim
62 words
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.
Claim 10
Independent Claim
62 words
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.
Claim 11
Dependent Claim
22 words
The method of claim 8 , wherein the SCR is caused to close at a desired phase angle of the power supply.
Claim 12
Dependent Claim
22 words
The method of claim 8 , wherein determining comprises sampling a transient response of the induction motor with a digital signal processor.
Claim 13
Dependent Claim
32 words
The method of claim 8 , wherein determining comprises calculating an inductance and resistance with a least square algorithm, a least mean square algorithm, a maximum likelihood algorithm, or a combination thereof.
Claim 14
Dependent Claim
19 words
The method of claim 8 , comprising storing a determined inductance value and a determined resistance value in memory.
Claim 15
Dependent Claim
20 words
The method of claim 8 , comprising calculating a temperature of an induction motor based on the determined resistance value.
Claim 16
Dependent Claim
35 words
The method of claim 8 , comprising: closing the switch a second time; determining an inductance, resistance, or both a second time; and calculating another motor parameter based on the result of both determining steps.
Claim 17
Dependent Claim
23 words
The method of claim 8 , comprising exercising in-situ feedback control of an induction motor based on the determined resistance and inductance values.
Claim 18
Independent Claim
76 words
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.
Claim 19
Independent Claim
76 words
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.
Claim 20
Dependent Claim
32 words
The method of claim 16 , wherein determining comprises calculating an inductance and resistance with a least square algorithm, a least mean square algorithm, a maximum likelihood algorithm, or a combination thereof.
Claim 21
Dependent Claim
19 words
The method of claim 16 , comprising storing a determined inductance value and a determined resistance value in memory.
Claim 22
Dependent Claim
23 words
The method of claim 16 , comprising exercising in-situ feedback control of an induction motor based on the determined resistance and inductance values.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2014-01-10 | 2014-07-12 | 2015-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2018-01-10 | 2018-07-12 | 2019-01-11 | $3760.00 | Window Closed / Lapsed |
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