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Title: Apparatus and method for non-invasive diagnosis and control of motor operated valve condition

Abstract

An apparatus compares the torque from an MOV motor with the valve displacement, and from the comparison assesses MOV operating condition. A transducer measures the vibration of the housing of an MOV. The vibrations are due to the motions of the rotating elements within the housing, which motions are directly related to the motion of the valve relative to its seat. Signal processing apparatus analyzes the vibrations to recover the rotations of the rotating elements and thus the motion of the valve plug. Lost motion can also be determined (if a lost motion connection exists) by demodulating the vibration signal and thus taking into account also the lost motion. Simultaneously, the forces applied to the valve are estimated by estimating the torque between the stator and the rotor of the motor. Such torque can be estimated from measuring the input current and voltage alone, using a forgetting factor and a correction for the forgetting factor. A signature derived from relating the torque to the valve position can be used to assess the condition of the MOV, by comparing the signature to signatures for MOVs of known conditions. The vibration analysis components generate signals that relate to the position of elementsmore » in the operator. Similarly, the torque estimator estimates the torque output by any type of electric motor, whether or not part of an MOV analysis unit.« less

Inventors:
 [1];  [2];  [3];  [1];  [1];  [4]
  1. Belmont, MA
  2. Seoul, KR
  3. Sudbury, MA
  4. Helsinki, FI
Publication Date:
Research Org.:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
OSTI Identifier:
870785
Patent Number(s):
US 5594175
Assignee:
Massachusetts Institute of Technology (Cambridge, MA)
DOE Contract Number:  
W-7405-ENG-36
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
apparatus; method; non-invasive; diagnosis; control; motor; operated; valve; condition; compares; torque; mov; displacement; comparison; assesses; operating; transducer; measures; vibration; housing; vibrations; due; motions; rotating; elements; directly; related; motion; relative; seat; signal; processing; analyzes; recover; rotations; plug; lost; determined; connection; exists; demodulating; taking; account; simultaneously; forces; applied; estimated; estimating; stator; rotor; measuring; input; current; voltage; forgetting; factor; correction; signature; derived; relating; position; assess; comparing; signatures; movs; conditions; analysis; components; generate; signals; relate; operator; similarly; estimator; estimates; output; type; electric; unit; analysis unit; directly related; signal processing; electric motor; processing apparatus; forces applied; operating condition; valve plug; operated valve; motor operated; generate signals; vibration signal; torque output; rotating element; signal process; valve position; transducer measures; /73/

Citation Formats

Lyon, Richard H, Chai, Jangbom, Lang, Jeffrey H, Hagman, Wayne H, Umans, Stephen D, and Saarela, Olli J. Apparatus and method for non-invasive diagnosis and control of motor operated valve condition. United States: N. p., 1997. Web.
Lyon, Richard H, Chai, Jangbom, Lang, Jeffrey H, Hagman, Wayne H, Umans, Stephen D, & Saarela, Olli J. Apparatus and method for non-invasive diagnosis and control of motor operated valve condition. United States.
Lyon, Richard H, Chai, Jangbom, Lang, Jeffrey H, Hagman, Wayne H, Umans, Stephen D, and Saarela, Olli J. 1997. "Apparatus and method for non-invasive diagnosis and control of motor operated valve condition". United States. https://www.osti.gov/servlets/purl/870785.
@article{osti_870785,
title = {Apparatus and method for non-invasive diagnosis and control of motor operated valve condition},
author = {Lyon, Richard H and Chai, Jangbom and Lang, Jeffrey H and Hagman, Wayne H and Umans, Stephen D and Saarela, Olli J},
abstractNote = {An apparatus compares the torque from an MOV motor with the valve displacement, and from the comparison assesses MOV operating condition. A transducer measures the vibration of the housing of an MOV. The vibrations are due to the motions of the rotating elements within the housing, which motions are directly related to the motion of the valve relative to its seat. Signal processing apparatus analyzes the vibrations to recover the rotations of the rotating elements and thus the motion of the valve plug. Lost motion can also be determined (if a lost motion connection exists) by demodulating the vibration signal and thus taking into account also the lost motion. Simultaneously, the forces applied to the valve are estimated by estimating the torque between the stator and the rotor of the motor. Such torque can be estimated from measuring the input current and voltage alone, using a forgetting factor and a correction for the forgetting factor. A signature derived from relating the torque to the valve position can be used to assess the condition of the MOV, by comparing the signature to signatures for MOVs of known conditions. The vibration analysis components generate signals that relate to the position of elements in the operator. Similarly, the torque estimator estimates the torque output by any type of electric motor, whether or not part of an MOV analysis unit.},
doi = {},
url = {https://www.osti.gov/biblio/870785}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Jan 01 00:00:00 EST 1997},
month = {Wed Jan 01 00:00:00 EST 1997}
}

Works referenced in this record:

Estimation of the time-varying frequency of a signal: the Cramer-Rao bound and the application of Wigner distribution
journal, March 1990


On separating amplitude from frequency modulations using energy operators
conference, January 1992