Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9841860 | Physica C: Superconductivity and its Applications | 2005 | 10 Pages |
Abstract
High voltage breakdown (HVbd) tests were performed to investigate electrical properties of high temperature MgO-ZrO2 insulation coatings on long-length stainless steel (SS) tapes under various pressures at room temperature (298 K) and liquid nitrogen temperature (77 K) for applications of HTS/LTS coils and magnets. After solutions were prepared from Mg and Zr based precursors, solvent and chelating agent, the coating were fabricated on SS substrates using reel-to-reel sol-gel technique. Coating thicknesses for 4, 8, and 9 dippings were about 7, 12, and 13 μm, respectively, and thickness of epoxy-impregnated samples (stycast 2850 FT/24 LV) were measured to be 32 μm. The pressure from 0 GPa to 0.54 GPa was applied on to test couples, the stycast thicknesses between the layers were varied 32-20 μm. Thickness of the coatings and epoxy-impregnated using stycast were determined by using environmental scanning electron microscopy (ESEM). The resistance, capacitance, and HVbd of the samples were measured by using standard machines HP 439 a high resistance meter, 161 analog digital capacitance meter and model 200-02R high voltage power supply, respectively. Electric strength and dielectric constant were calculated at 298 and 77 K under various pressures. The high HVbd, and electric strength values of the samples were 2.84 kV and 45.91 kV/mm, respectively. ESEM observation revealed that arcing spots in the insulation coatings become larger and deeper for higher HVbd's.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
O. Cakiroglu, L. Arda, Y.S. Hascicek,