Date of Award

8-2008

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Electrical Engineering

Advisor

Collins, Edward R

Committee Member

Makram , Elham B

Committee Member

Bridgwood , Michael

Abstract

Electricity meters are devices that continuously record electrical energy consumption. In the past, meters have been of electromechanical type and consisted windings and moving parts. Electromechanical meters tend to be bulky, less accurate and more susceptible to tampering. As with other aging power system infrastructure in the US, most electricity meters are around 40 years old and are nearing the end of their intended lifespan. Concerns over the accuracy of these electromechanical meters along with advances in technology have led to development of new electronic meters which have additional benefits such as light weight, tamper-proof mechanisms, harmonic detection and Advanced Metering Infrastructure (AMI) features. Utilities intend to spend millions of dollars over the next few years in replacing these aging electromechanical meters; however the new meters contain electronic parts that are typically more sensitive to environmental conditions and abnormal voltage conditions. The drive to replace older meters will not meet the expectations, either in terms of functionality or expected profits, if the new meters drift in accuracy or fail relatively quickly with respect to their electromechanical counterparts.
In this thesis, reliability techniques that are used in the industry, for prediction of product quality information have been reviewed. Accelerated Life Test (ALT) plans have been developed to systematically study the effect of environmental stresses on electronic revenue meters by using degradation parameters, failure time distributions, and accelerating factors to predict their operational lifetime. A Human Machine Interface (HMI) was developed in LabVIEW to interface the data acquisition devices with software, and thus facilitate continuous monitoring of environmental parameters and the health of test specimens placed inside an environmental chamber. The HMI also has the capability of generating automated periodic reports and emails for review by management.
Since the lab test data from accelerated life testing of electronic meters was yet to be obtained, the statistical analysis procedure, derived from literature review, was demonstrated with the help of ALT data from other electrical and electronic components. ALT data for cable insulation was obtained from literature and the failure data analysis was demonstrated, followed by an analysis of degradation data from LEDs. Finally, the causes of lack of data were analyzed and improvements in testing procedure were recommended.

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