The improved damping of superconductor bearings for 35kWh superconductor flywheel energy storage system
| Autor: | Se-Yong Jung, Y. C. Bae, Byung-Jun Park, Young-Hee Han, Wook-Ryun Lee, S. C. Han |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Superconductivity
Materials science Bearing (mechanical) Energy Engineering and Power Technology Condensed Matter Physics Flywheel Electronic Optical and Magnetic Materials law.invention Damper Thermoelastic damping Critical speed law Magnet Magnetic damping Electrical and Electronic Engineering Composite material |
| Zdroj: | Physica C: Superconductivity. 485:102-106 |
| ISSN: | 0921-4534 |
| DOI: | 10.1016/j.physc.2012.11.003 |
| Popis: | A 35 kWh Superconductor Flywheel Energy Storage system (SFES) using hybrid bearing sets, which is composed of a high temperature superconductor (HTS) bearing and an active magnet damper (AMD), has been developed at KEPCO Research Institute (KEPRI). Damping is a source of energy loss but necessary for the stability of the flywheel system. We found that the damping of HTS bearings can be improved by thermal insulating bolts, which play a role of passive type external damper. To investigate the source of the increased damping, damping coefficients were measured with HTS bearings using insulating bolts made of three kinds of polymer materials. The damping coefficient was raised over 3000 N s/m in the case of PEEK bolts. The value was almost a quarter of the AMD. In this study, thermoelastic and Coulomb friction damping mechanisms are discussed. The main damping mechanism was the thermoelastic damping of the bolts themselves. And interfacial gap between the insulating bolt and metal chamber, which increased during the cooling process, was considered to be the cause of the anisotropic damping coefficients. Finally, the effects of the HTS bearings on the first critical speed are shown. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect