Fault detection in induction motors based on current signature analysis
First Claim
1. A method for detecting faults during a steady state of an operation of an induction motor, comprising:
- measuring, in a time domain, a signal of a current powering the induction motor with a fundamental frequency;
determining, in a frequency domain, a set of frequencies with non-zero amplitudes, such that a reconstructed signal formed by the set of frequencies with non-zero amplitudes approximates the signal measured in the time domain, wherein the determining includes a compressive sensing via searching within a subband including the fundamental frequency of the signal subject to condition of a sparsity of the signal in the frequency domain;
detecting a fault in the induction motor if the set of frequencies includes a fault frequency different from the fundamental frequency; and
determining a type of the fault based on an amplitude of the fault frequency, wherein the type includes one or combination of a partial broken bar and a number of broken bars, wherein the type of the fault is the partial broken bar if the amplitude of the fault frequency is less than a threshold, wherein steps of the method are performed by a processor.
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Abstract
A method detects faults during a steady state of an operation of an induction motor. The method measures, in a time domain, a signal of a current powering the induction motor with a fundamental frequency and determines, in a frequency domain, a set of frequencies with non-zero amplitudes, such that a reconstructed signal formed by the set of frequencies with non-zero amplitudes approximates the signal measured in the time domain. The determining includes a compressive sensing via searching within a subband including the fundamental frequency of the signal subject to condition of a sparsity of the signal in the frequency domain. The method detects a fault in the induction motor if the set of frequencies includes a fault frequency different from the fundamental frequency.
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Citations
14 Claims
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1. A method for detecting faults during a steady state of an operation of an induction motor, comprising:
- measuring, in a time domain, a signal of a current powering the induction motor with a fundamental frequency;
determining, in a frequency domain, a set of frequencies with non-zero amplitudes, such that a reconstructed signal formed by the set of frequencies with non-zero amplitudes approximates the signal measured in the time domain, wherein the determining includes a compressive sensing via searching within a subband including the fundamental frequency of the signal subject to condition of a sparsity of the signal in the frequency domain;
detecting a fault in the induction motor if the set of frequencies includes a fault frequency different from the fundamental frequency; and
determining a type of the fault based on an amplitude of the fault frequency, wherein the type includes one or combination of a partial broken bar and a number of broken bars, wherein the type of the fault is the partial broken bar if the amplitude of the fault frequency is less than a threshold, wherein steps of the method are performed by a processor. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- measuring, in a time domain, a signal of a current powering the induction motor with a fundamental frequency;
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8. A system for operating an induction motor having a stator and rotor bars, comprising:
- a power supply for powering the stator of the induction motor with a stator current having a fundamental frequency;
a sensor for measuring, in a time domain, a signal of a stator current powering the induction motor, wherein the measuring includes sampling the signal for a period of time during a steady state of the operation of the induction motor with a sampling rate of at least twice of a fundamental frequency of the stator current;
a processor for determining, in a frequency domain, a set of frequencies with non-zero amplitudes, such that a reconstructed signal formed by the frequencies with corresponding amplitudes approximates the signal measured in the time domain, wherein the determining includes searching within a subband including the fundamental frequency subject to condition of a sparsity of the signal in the frequency domain; and
a user interface for signaling the fault, if the set of frequencies includes a fault frequency approaching a dominant frequency, wherein the processor determines a type of the fault base amplitude of the fault frequency, wherein the type includes one or combination of a partial broken bar and a number of broken bars, wherein the type of the fault is the partial broken bar if the amplitude of the fault frequency is less than a threshold. - View Dependent Claims (9, 10, 11, 12, 13)
- a power supply for powering the stator of the induction motor with a stator current having a fundamental frequency;
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14. A method for detecting faults during a steady state of an operation of an induction motor, comprising:
- measuring, in a time domain, a signal of a current powering the induction motor with a fundamental frequency;
determining, in a frequency domain, a set of frequencies with non-zero amplitudes, such that a reconstructed signal formed by the set of frequencies with non-zero amplitudes approximates the signal measured in the time domain, wherein the determining includes a compressive sensing via searching within a subband including the fundamental frequency of the signal subject to condition of a sparsity of the signal in the frequency domain;
detecting a fault in the induction motor if the set of frequencies includes a fault frequency different from the fundamental frequency;
determining a type of the fault based on an amplitude of the pair, wherein the type includes one or combination of a partial broken bar and a number of broken bars;
determining a set of thresholds, each threshold in the set corresponds to a value of the number of broken bars; and
comparing the amplitude of the fault frequency with the set of thresholds to determine the number of the broken bars, wherein steps of the method are performed by a processor.
- measuring, in a time domain, a signal of a current powering the induction motor with a fundamental frequency;
Specification