The Unique Interaction Behavior Between A Superconductor Coil And A Magnet: A Comprehensive Review

Abstract

It was found that the interaction between a superconductor coil and a magnet does not comply with one of the primary interpretations of Lenz's law: "the current induced in a circuit due to a change or a motion in a magnetic field is directed so as to exert a mechanical force opposing the motion." There are a number of exclusive features in the interaction between a superconducting coil and a magnet. The discovery of this unique behavioural interaction leads to a principle of developing a new kind of superconducting energy conversion/storage device.  With a high-temperature superconducting (HTS) coil and a magnet, this new device is able to complete an energy conversion cycle from mechanical to electromagnetic then to mechanical without need of either a power supply or a motor/generator. Intrinsically, this kind of device has a simple structure, high energy conversion efficiency, high energy storage density, and low operation energy loss. Optimized configuration of the superconductor coil and magnets to enhance the storage capacity and conversion efficiency has been investigated and actualized with theoretical analysis, numerical modelling and experimentation. This article systematically reviews the discovery, the working principle and state of the art of the new energy convertor/storage device as well as its application potentials.