Axial and radial offset characteristics of high temperature superconducting wireless power transfer system

•The offset characteristics of HTS wireless power transfer (WPT) system was investigated systematically.•The transfer efficiency decreases monotonically with the increase of offset distance. A “flat top” exists in transfer efficiency at short-range radial offset, benefiting the practical applications.•The relationship between load receiving power (LRP) and offset distance is not monotonic. There is an optimal position to reach corresponding maximum LRP.•The HTS WPT system exhibits superior performance in both transfer efficiency and LRP than the copper WPT system. The usage of high-temperature superconducting (HTS) coils in magnetically-coupled resonant wireless power transfer (WPT) systems can considerably improve the transfer efficiency, and hence it attacked great attention. However, there are few studies on offset characteristics in HTS WPT systems. In order to further improve the performance of HTS WPT systems, we have studied experimentally the influences of relative displacement of the coils on the transfer efficiency and load receiving power (LRP) in a magnetically-coupled resonant WPT system. The WPT systems using copper coils and HTS coils were carefully compared. The results show that the transfer efficiency decreases monotonically with the increasing offset. However, there is an optimal position for the LRP to achieve the maximum value. Both the transfer efficiency and LRP of the HTS WPT system are higher than those of the copper WPT system under the same conditions.