A Compact HTS 5 kWh/250 kW Flywheel Energy Storage System

Self Cite

The considerable development effort of HTS magnetic bearings with respect to heavy loads is demonstrated. Radial type 200 mm bearing in an optimized design was developed for implementation in a new 5 kWh superconducting flywheel energy storage system. A prototype bearing, consisting of a modular assembled melt textured YBCO bulk 200 mm hollow cylinder with permanent magnet rotor is presented. Axial rotor displacement causes pinning forces of 8 and 10 kN axially at a temperature of 78 K and 71 K, respectively. Maximum radial forces are 4.7 kN at sub-cooled LN2. Fabrication technology incorporates the construction and engineering of a low-weight, nonmagnetic G-10 bearing cryostat. Ultra-low heat transfer structural elements were designed and constructed to reduce the thermal loss through the support to less than 2 Watt under 1 ton load.

“…The experimental details are described in [5]. The radial damping coefficient was estimated from the consecutive amplitude ratios measured after a hammer struck.…”

Section: B Dampingmentioning

confidence: 99%

“…The prototype bearing was designed and constructed in ATZ' s laboratory. The bearing is tested for application in a new 5 kWh/280 kW superconducting flywheel which is developed within a German project together with Magnet-Motor Co., Starnberg, Germany [5].…”

Section: Introductionmentioning

confidence: 99%

Fabrication of HTS Bearings With Ton Load Performance

Floegel-Delor

Rothfeld

Wippich

et al. 2007

Self Cite

“…According to (5) and (6), we can obtain the equations of radial translation of the rotor based on (2) as follows:…”

Section: Simulation and Experimental Resultsmentioning

confidence: 99%

Superconducting Magnetic Bearings and Active Magnetic Bearings in Attitude Control and Energy Storage Flywheel for Spacecraft

Tang

Fang

Wen

2012

For an attitude control and energy storage flywheel (ACESF), not only does the speed of the rotor must be high but also the position of the rotor must be controlled accurately. To research the relationship between superconducting magnetic bearings (SMBs) and active magnetic bearings (AMBs) in this presented superconducting ACESF, the rotor model is established, the force of SMBs and AMBs is simplified by linearization, and the radial translation and tilting movement of the rotor suspended by only SMBs, SMBs with equivalent permanent-magnet bearings, and SMBs and AMBs with proportional-derivative-type control are researched, respectively. For the disklike rigid rotor with large inertia and high speed, simulation and experimental results proved that the gyroscopic effect of the rotor is prominent, the rotor model including gyroscopic couples can describe its behaviors, and the linearization of force for SMBs and AMBs are reasonable. The AMB can suppress the nutation and precession of the rotor effectively by a cross-feedback control method or other modern control methods; the SMB, together with the AMB, can make the rotor in ACESF be stable and the amplitude of the vibration of rotor be small.Index Terms-Active magnetic bearing (AMB), attitude control and energy storage flywheel (ACESF), gyroscopic effect, superconducting magnetic bearing (SMB).

“…The applications of bulk superconductors can be clarified mainly into two aspects: levitation devices and trapped-field magnet devices. In the levitation aspect, the notable advantage of passive levitation has been impressively demonstrated with the prototypes of superconducting maglev vehicles [3], superconducting magnetic bearings [4] and its based flywheel energy storage systems [5], [6], superconducting non-contact conveyers, mixers or torque transfers [7]. While in the trapped- field magnet aspect, with the continuous material improvements in pinning doping, thermal stability and mechanical properties, the peak trapped field values of single-grain RE-Ba-Cu-O have reached 3 T at 77 K [8], 11 T at 47 K [9], and 17 T at 29 K [10].…”

Section: Introductionmentioning

confidence: 99%

Pulsed Field Magnetization Properties of Bulk RE-Ba-Cu-O as Pole-Field Magnets for HTS Rotating Machines

Deng

Miki

Tsuzuki

et al. 2011

Aiming at exploiting the high trapped field ability of bulk high-temperature RE-Ba-Cu-O (RE: rare-earth elements) superconductors, a brushless axial-gap type superconducting synchronous motor has been successfully developed as a technology demonstrator using eight melt-textured GdBa 2 Cu 3 O y (Gd-123) bulks as pole-field magnets. An output power of 10 kW at 720 rpm was realized by an average trapped field peak of 0.56 T reaching the armature coils, under a pulsed field excitation at the liquid nitrogen temperature. For such motors, to improve the trapped flux of bulks is a direct way to enhance the motor performance. In order to obtain a high trapped flux density with a regular shape for a high performance motor utilization, the pulsed field magne- tization (PFM) properties of two kinds of bulk superconductors have been investigated. By a reasonable multi-PFM process with a pair of vortex-type pulsed coils, it was found that the multi-seed Y-Ba-Cu-O bulk can bring a high average trapped field, while the single-grain Gd-Ba-Cu-O bulk under a size-adjustable pulsed coilcan obtain a very regular trapped field distribution. These results will be useful to the following optimization of the rotating machine system.Index Terms-High temperature superconductors, pole-field magnets, pulsed field magnetization, rotating machines, trapped field.