Three-phase pollution test of diamond- shaped … 10.1 Igor_Gutman.pdfThree-phase pollution test of...

Three-phase pollution test of diamond-shaped “suspension” insulator arrangement

for T-pylon tower

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Background and goal• The National Grid isplanning for the new 400kV overhead line with T-pylon towers

• Dielectric (lightning andswitching overvoltages)and ice performanceperformed by STRI

• Goal of this paper:verification of pollutionperformance

• Full-scale three-phasetest to be developed

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Challenges

• No IEC test for polymeric(composite) insulators

• No test for three-phasearrangement

• No IEC test for thesimulation of recovery ofhydrophobicity

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Methodology-1: principles of IEC 60507 (solid layer)

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Methodology-2: principles of CIGRE TB 555

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Methodology-3: full-scale three-phase tests from 3 single phase transformers

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High repeatability in pollution parameters

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High repeatability in leakage current parameters

Practical summary

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• Unique three phase full-scalepollution test for the complicatedgeometrical structure for 420 kVOHL equipped with compositeinsulators with hydrophobic surfacehas been successfully developed.

• Target pollution level withstood fortwo structures (no flashovers).

Scientific summary

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• The test is applicable for complicatedgeometrical structures.

• The test is repeatable.• Reported to CIGRE within workinggroup D1.44

• Verified at different configuration.

Thank You!

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