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Capacitance Measuring Robot |
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When water permeates the winding insulation in large-scale direct water-cooled turbine generators, dielectric strength drops steeply due to wet heat deterioration. To ensure operational reliability, it is essential to know whether or not water has permeated the insulation, and if so, to determine accurately the degree of deterioration. We have developed a capacitance measuring robot, which enables measurement near the stator core end without removing the rotor, and confirmed good results in the field. The robot travelling along the retaining ring can be accurately positioned, and measured capacitance are stable and reproducible. The robot minimizes the extent of disassembly and reassembly, thus greatly reducing the out-of-operation period. Further, because the insulation condition can be accurately determined through its periodical use, we believe that it will contribute to both preventing accidents and assuring generators with high reliability.
Advantages of the robot is below
(1) Reduction in measuring cost
(2) Reduction in generator shut-down period
(3) Establishment of an appropriate maintenance program
(4) Prevention of serious accidents and economic loss
 Life Estimation & Maintenance of Generator Stator Coil Insulation
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Title of Invention: Electrostatic capacitance measuring instrument for stator winding of electric rotating machine
United States Patent: 5682,102 (Oct. 28, 1997)
Canadian Patent: 2174709 (Jul. 13, 1999)
European Patent: EP 0 758 158 B1 (Dec. 29, 1999)
Chinese Patent: ZL 96 1 09403.6 (Apr.21, 2000)
Korean Patent: 236868 (Oct. 5, 1999)
Australian Patent: 707919 (Jul. 22, 1999)
Japanese Patent: 8-047823(Mar. 5,1996) |
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