Method and system for determining motor reliability
First Claim
1. A method for determining reliability and a remaining time before failure with statistical confidence for an electric motor system, comprising steps performed by a computer system of:
- acquiring and organizing historical motor repair data corresponding to the motor system into a computer system database;
continually monitoring and uploading operational parameter data from sensors at the motor system to the computer system;
performing failure analysis based on a composite of reliability probability distributions corresponding to predetermined sub-populations of historical motor system failure causes;
developing a causal network for modeling reliability of one or more motor system components and assessing motor system component condition based on the causal network;
performing an integrated causal network and reliability analysis of the motor system, wherein results from performing failure analysis based on historical data are integrated with analysis results based on the causal network to compute a quantitative value for a time remaining before failure with an acertained statistical confidence; and
outputing the computed value on a display device associated with the computer system.
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Accused Products
Abstract
The reliability and remaining time before failure for electric motor systems and the like is determined with an ascertained statistical confidence based on continually monitored system parameters and a database comprised of historical failure mode/cause and repair data concerning the same motor and/or similar motor systems. A computational process is followed that relies upon hierarchical failure-tree structures, Weibull probabillity distributions and directed causal networks and which updates the probabilities and models used to forecast the remaining time before system failure based on the monitored parameters. Motor system operational parameter data is continually monitored at the site of the motor system and up-loaded via wireless or other communications network to a remote computer system where a database is maintained and reliability analysis is performed.
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Citations
32 Claims
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1. A method for determining reliability and a remaining time before failure with statistical confidence for an electric motor system, comprising steps performed by a computer system of:
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acquiring and organizing historical motor repair data corresponding to the motor system into a computer system database;
continually monitoring and uploading operational parameter data from sensors at the motor system to the computer system;
performing failure analysis based on a composite of reliability probability distributions corresponding to predetermined sub-populations of historical motor system failure causes;
developing a causal network for modeling reliability of one or more motor system components and assessing motor system component condition based on the causal network;
performing an integrated causal network and reliability analysis of the motor system, wherein results from performing failure analysis based on historical data are integrated with analysis results based on the causal network to compute a quantitative value for a time remaining before failure with an acertained statistical confidence; and
outputing the computed value on a display device associated with the computer system. - View Dependent Claims (2, 3, 4)
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5. A method for assessing reliability and determining a quantitative value for time remaining before failure for electric motor systems and/or electric motor driven equipment, comprising the steps of:
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storing motor system failure rate data in a computer data base, said failure rate data based on historical test data and/or failure analysis of similar or identical motor systems and motor components;
perfroming a motor system fault-tree analysis based on data assembled in the failure rate data base;
constructing a reliability diagram, based on the fault tree, pertaining to a particular motor of interest;
modeling the historical failure rate data of one or more system components using one or more conventional probability distribution functions;
collecting motor operational parameter data acquired via motor system sensors located at the motor system site;
constructing conditional probabililty density functions based on the collected operational parameter data;
performing a Monte Carlo simulation of the motor system according to the reliability diagram using the conditional probability density functions; and
determining an overall motor system reliability distribution function the Monte Carlo simulation, wherein a statistical reliability of the motor system is assessed and a quantitative value for time remaining before failure is predicted with a statistical degree of confidence. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A system for determining electrical motor system reliability with an ascertained statistical confidence, comprising:
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a field data collection device located at a motor system site and connected to a digital communications network; and
a computer system coupled to the digital communications network and having access to a stored database of motor system failure rate information, said computer system programmed to;
model historical failure rate data of one or more system components using one or more conventional probability distribution functions;
collect motor operational parameter data acquired via motor system sensors located at the motor system site;
construct conditional probability functions based on the collected operational parameter data; and
compute motor system reliability according to the reliability hierarchy and probability density functions. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25)
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- 26. A diagnostic system for determining electric motor reliability, comprising a computer system having access to a database of motor system failure data, said computer system coupled to a field data collection device remotely located at a motor system site via a communications network and said field data collection device acquiring and up-loading operational parameter data concerning the motor to the computer system, wherein a statistical reliability of the motor system is assessed and a quantitative value for time remaining before motor system failure is predicted with a statistical degree of confidence.
Specification