Non-intrusive fault detection in reciprocating compressors

This thesis presents a set of techniques for non-intrusive sensing and fault detection in reciprocating compressors driven by induction motors. The procedures developed here are "non-intrusive" because they rely only on electrical measurements to reconstruct the mechanical signals internal to the compressor. This allows for easy and non-intrusive determination of many fault sensitive signals that usually require complicated, expensive, and time consuming operations to measure. A sample of the signals produced by the procedures of this thesis are estimates of the cylinder suction and discharge pressures and a composite torque signal containing the effects of the mechanical loads within the compressor. This load torque signal is especially sensitive to faults, and a demonstration of the effect on and detection of compressor valve faults from the load torque signal is given. One of the key steps in the algorithm presented here is a procedure to "invert" the induction motor dynamic model equations to allow direct calculation of motor shaft speed and torque from stator current and voltage measurements. For this procedure a non-intrusive method to estimate motor model parameters from an in-situ induction motor driving a periodic load was developed.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2011

Author dc:creator

• Schantz, Christopher James

Advisor dc:contributor.advisor

• Steven B. Leeb.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/67800

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/67800