Experimental study of a novel superconducting energy conversion/storage device

Exploration on the application of a new type of superconducting energy storage for regenerative braking in urban rail transit

“…Obviously, this feature makes the new energy storage more efficient in mechanical energy conversion than any other energy storage devices. From the previous studies [6,7], the cycle efficiency of energy conversion from mechanical to mechanical is higher than 80%, and it has been proved that the cycle efficiency can increase with the increase in energy storage capacity. From the experimental results of a prototype with the magnet-optimized configuration, the cycle efficiency is up to 88% [7].…”

“…The first proposed new superconducting energy storage is composed of one closed superconducting coil and one permanent magnet (the configuration of one-magnet-one-coil is called original configuration hereafter in this article). It has been proved that the new superconducting energy storage exhibits a unique mechanism for mechanical energy conversion, storage, and release [6]. As shown in figure 8, the permanent magnet is directly coupled with the external component working on mechanical energy, such as gearbox.…”

“…In the whole energy cycle, the energy can be converted directly from mechanical to electromagnetic then to mechanical without any intermediate equipment, such as motor, generator, and power electronics convertor. Based on the previous studies [6,44], the schematic curve of the force on permanent magnet versus the displacement of permanent magnet is sketched in figure 9. In the figure, the shadow areas visually depict the mechanical energy input/output through the force on the permanent magnet during the energy cycle.…”

“…The first study of the new superconducting energy storage is conducted on a proof-of-concept prototype, which is built with the original configuration [6]. The results of this study have demonstrated that the conversion efficiency between mechanical energy and electromagnetic energy is greater than 91%, and the energy loss mainly caused by joule heating on joint resistance of superconducting coil is less than 2% of its capacity in period of 30 min.…”

“…Superconductors have been employed to advance a number of transportation technologies, such as SCMAGLEV for high speed rail transportation [1,2], light weight and high power density motors for ship and aircraft propulsion [3][4][5]. In last few years, our group proposed and investigated a new kind of superconducting energy storage/convertor [6,7]. Based on the characteristic of this kind of device, one of its potential applications is for regenerative braking in urban rail transit.…”