Motor current signature analysis method for diagnosing motor operated devices

[54] MOTOR CURRENT SIGNATURE ANALYSIS METHOD FOR DIAGNOSING MOTOR OPERATED DEVICES

[75] Inventors: Howard D. Haynes, Kingston; David M. Eissenberg, Oak Ridge, both of Tenn.

[73] Assignee: Martin Marietta Energy Systems, Inc., Oak Ridge, Tenn.

[21] Appl. No.: 436,139

[22] Filed: Not. 14,1989

Related U.S. Application Data

[63] Continuation of Ser. No. 913,193, Sep. 30, 1986, abandoned.

[51] Int CI.* G01R 23/00; G01R 31/02

[52] U.S. CI 324/158 MG; 73/659;

318/490

[58] Field of Search 318/490; 324/158 MG;

364/551; 361/31; 340/648; 73/593, 659, 168,

660

[56] References Cited

U.S. PATENT DOCUMENTS

3,052,117 9/1962 Miller et al 324/158 MG

3,292,425 12/1966 Conn 73/660

3,793,509 2/1974 Isnard 324/158 MG

4,123,009 10/1978 Kilpinen 324/158 MG

4,302,712 11/1981 Pritchard 318/490

4,380,172 4/1983 Imam et al 73/659

4,471,308 9/1984 Gable et al 324/158 MG

4,527,101 7/1985 Zavis et al 318/490

4,542,649 9/1985 Charbonneau et al 73/168

4,602,343 7/1986 Dougherty 364/551

4,744,041 5/1988 Strunk et al 318/490

4,773,263 9/1988 Lesage et al 73/659

A motor current noise signature analysis method and apparatus for remotely monitoring the operating characteristics of an electric motor-operated device such as a motor-operated valve. Frequency domain signal analysis techniques are applied to a conditioned motor current signal to distinctly identify various operating parameters of the motor driven device from the motor current signature. The signature may be recorded and compared with subsequent signatures to detect operating abnormalities and degradation of the device. This diagnostic method does not require special equipment to be installed on the motor-operated device, and the current sensing may be performed at remote control locations, e.g., where the motor-operated devices are used in accessible or hostile environments.

4 Claims, 3 Drawing Sheets