A novel micro-thrust measuring method based on magnetic levitation using high temperature superconductors

Design of a thrust stand is crucial for evaluating electric propulsion performance. In order to prevent connecting interferences and bring higher precision, a thrust measuring method using superconducting magnetic levitation is proposed to be applied in the micro-thrust measurement to achieve a fully suspending thrust stand. The principle of superconducting levitation is first presented, and then levitation friction loss and cogging torque effect are considered as main features affecting the levitation application to the thrust stand. A set of single permanent magnet (PM)/superconductor levitating rotation setup was designed and fabricated to investigate the friction loss and cogging torque characteristics of the superconducting levitation. The spin-up of the PM is provided by cold nitrogen gas stored in a gascylinder, and the swinging angle of the rotating PM is recorded by an optical method using CCD cameras. The research shows the cogging torque feature in the HTS levitation is position dependent and can be used to develop the micro-thrust measuring device.