Proactive motor monitoring for avoiding premature failures and for fault recognition
First Claim
1. Apparatus for monitoring the condition of at least one AC induction motor, said apparatus comprising:
- a motor temperature measuring device for measuring the temperature of at least one motor temperature measurement point during motor operation;
an ambient temperature measuring device;
a magnetic flux transducer for sensing magnetic flux generated by the motor during motor operation; and
a data processing system arranged to receive data from said motor temperature measuring device, from said ambient temperature measuring device, and from said magnetic flux transducer;
said data processing system being operable to determine motor load based on sensed magnetic flux and to calculate a normalized temperature rise parameter as a function directly related to the difference between motor temperature and ambient temperature and inversely related to motor load, and being further operable to perform a frequency spectrum analysis of motor magnetic flux to find a set of peaks each characterized by a frequency and an amplitude, and to identify from the set of peaks a subset of peaks in accordance with predetermined identity criteria for purposes of comparison.
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Accused Products
Abstract
Apparatus which automates the collection of motor temperature, flux and shaft current data for proactive motor maintenance. Motor speed is determined by an analysis of the flux frequency spectrum, and motor load is determined based on speed, from which a normalized thermal parameter is then determined. From a spectrum analysis of magnetic flux signals a set of peaks each characterized by a frequency and an amplitude is found, and a subset of peaks is identified in accordance with predetermined identity criteria for purposes of comparison. Temperature, magnetic flux and shaft current data are trended to provide early indications of degradation, as well as for recognizing faults.
77 Citations
37 Claims
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1. Apparatus for monitoring the condition of at least one AC induction motor, said apparatus comprising:
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a motor temperature measuring device for measuring the temperature of at least one motor temperature measurement point during motor operation; an ambient temperature measuring device; a magnetic flux transducer for sensing magnetic flux generated by the motor during motor operation; and a data processing system arranged to receive data from said motor temperature measuring device, from said ambient temperature measuring device, and from said magnetic flux transducer; said data processing system being operable to determine motor load based on sensed magnetic flux and to calculate a normalized temperature rise parameter as a function directly related to the difference between motor temperature and ambient temperature and inversely related to motor load, and being further operable to perform a frequency spectrum analysis of motor magnetic flux to find a set of peaks each characterized by a frequency and an amplitude, and to identify from the set of peaks a subset of peaks in accordance with predetermined identity criteria for purposes of comparison. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. Apparatus for monitoring the condition of at least one AC induction motor, said apparatus comprising:
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a motor temperature measuring device for measuring the temperature of at least one motor temperature measurement point during motor operation; an ambient temperature measuring device; a magnetic flux transducer for sensing magnetic flux generated by the motor during motor operation; and a data processing system arranged to receive data from said motor temperature measuring device, from said ambient temperature measuring device, and from said magnetic flux transducer; said data processing system being operable to determine motor load based on sensed magnetic flux and to calculate a normalized temperature rise parameter as a function directly related to the difference between motor temperature and ambient temperature and inversely related to motor load. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. Apparatus for monitoring the condition of at least one AC induction motor, said apparatus comprising:
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a motor temperature measuring device for measuring the temperature of at least one motor temperature measurement point during motor operation; an ambient temperature measuring device; a device for determining motor speed; and a data processing system arranged to receive data from said motor temperature measuring device, from said ambient temperature measuring device, and from said device for determining motor speed; said data processing system being operable to determine motor load based on motor speed and to calculate a normalized temperature rise parameter as a function directly related to the difference between motor temperature and ambient temperature and inversely related to motor load. - View Dependent Claims (23, 24, 25, 26, 27)
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28. Apparatus for monitoring the condition of at least one AC induction motor, said apparatus comprising:
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a magnetic flux transducer for sensing magnetic flux generated by the motor during motor operation; and a data processing system arranged to receive data from said magnetic flux transducer and operable to perform a frequency spectrum analysis of motor magnetic flux to find a set of peaks each characterized by a frequency and an amplitude, and to identify from the set of peaks a subset of peaks in accordance with predetermined identity criteria for purposes of comparison. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37)
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Specification