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Electrical Equipment [clear filter]
Thursday, May 16
 

8:30am

9:00am

Fiber Optic Distributed Temperature Sensing for Real Time Monitoring of Electrical Systems Interconnections
Electrical distribution systems require annual inspection of bolted interconnections to identify loose parts and prevent arcing. This periodic maintenance is becoming increasingly critical on US Navy vessels since many ships are designed with electrical distribution systems of 4,160 VAC (Medium Voltage - MV) and 13,800 VAC (High Voltage - HV). Additionally, new power transmission systems are under development where multiple segments of electricity carrying insulated bus pipes will be connected with bolted hardware. Inspecting electrical system components at these voltage levels involves a time consuming preparation and assessment process to insure safety of the personnel and avoid potentially hazardous conditions.
Another issue of these periodic inspections is that an interconnection may be acceptable at time of inspection but loosen up shortly after and cause damage before the next inspection cycle. The optimal inspection system would consist of continuously monitoring the interconnection points to detect the formation of faults at the very early stages.
The fiber optic distributed sensing (DTS) technology where the entire length of an optical fiber becomes a continuous temperature detecting device can be utilized to remotely monitor the electrical interconnect point and also monitor electrical cables, machinery, and other electrical devices. This technology is used extensively for applications including oil and gas extraction, transport, and processing, fire detection in buildings and tunnels, monitoring the operation of power cables, and geo-hydrological systems monitoring.

A number of development efforts funded by the National Shipbuilding Research Program applied the DTS technology using Raman scattering for the detection of loose connections in MV and HV electrical panels and to monitor the interconnection points of an electrical distribution system using insulated bus pipes. Both applications presented a number of challenges including insuring that a sufficient length of fiber was used to provide accurate detection, multiple closely spaced measurement points could be accurately identified and measured, and that the fiber was installed in contact with the surface being measured.

The trials confirmed that the Raman DTS can be used to effectively monitor electrical connections. Additionally the efforts also demonstrated that the DTS system can use the same optical fiber cable length to monitor other conditions and devices including temperatures of zones where the cable is routed and machinery, including using the system for fire detection.
Challenges to be addressed for the full scale implementation of this versatile technology on naval vessels include: a) facilitating the methods of application of the sensing fiber to the parts monitored; b) connections of multiple fiber segments monitoring individual devices to create a continuous length of fiber connected to one single sensing channel; and c) programming the DTS device to identify the individual devices and zones, with the temperature ranges and alarms specific to each zone and device.
The presentation will describe the applications of the DTS technology evaluated through these NSRP programs, the results of the tests performed, the follow on efforts required for wide scale implementation on Navy vessels, and how these can be applied to monitoring commercial electrical systems.

Speakers
avatar for Giovanni Tomasi

Giovanni Tomasi

CEO / Chief Technology Officer, RSL Fiber Systems, LLC
Giovanni P. Tomasi is the founding CEO and Chief Technology Officer of RSL Fiber Systems, LLC. He has been involved in the military shipbuilding industry for over 30 years, starting in the 1980’s collaborating with the shipyards and the Navy to define the requirements and develop... Read More →


Thursday May 16, 2019 9:00am - 9:30am
Freedom Ballroom V

9:30am

11:00am

Electromechanical Actuator a Case Study: Multivariate Analysis of Phase Currents to Detect Three Types of Faults
This paper describes an multivariate-analysis (MVA) methodology to detect and prognose three types of faults associated with an electromechanical actuator (EMA). The faults are the following: (1) loading faults, such as friction, on the shaft of an EMA motor, (2) shorting faults in the stator windings of the EMA motor, and (3) on-resistance faults in one or more power-switching transistors used to convert direct voltage/current into alternating current. The presented methodology overcome difficulties associated with typical MVA methods such as the following examples: solving simultaneous equations, performing a statistical-based analysis such principal component analyses (PCA), and a K-nearest neighbor (KNN) regression or other Euclidean-based distance methods. Examples of those difficulties are the following: (1) 'noise' in the data containing the signal(s) of interest, (2) method produces information suitable for classification' rather than diagnosis or prognosis; and (3) the data does not include known independent variables, rather all variables in the data are dependent - which is the case for the phase currents of an EMA. A unique root-mean-square (RMS) of quantifying phase current values and a methodology for using those values are presented with examples that demonstrate that phase-current data for each of the three faults can be processed to unequivocally identify and isolate the fault, and to prognose a future time at which functional failure is likely to occur.

Speakers
avatar for James Hofmeister

James Hofmeister

Distinguished Engineer, Ridgetop Group, Inc.


Thursday May 16, 2019 11:00am - 11:30am
Freedom Ballroom V

11:30am

Interference of Variable Actuator a Case Study: Multivariate Analysis of Phase Currents to Detect Three Types of Faults
Speakers
avatar for Suri Ganeriwala

Suri Ganeriwala

Founder and President, SpectraQuest
Dr. Suri Ganeriwala is founder and president of Spectra Quest, Inc. He has over thirty-five years of industrial and academic experience in machinery vibration diagnostics and control, signal processing, and viscoelastic materials characterization. Suri has worked for Philip Morris... Read More →


Thursday May 16, 2019 11:30am - 12:00pm
Freedom Ballroom V