Superconducting Switch Rectifiers using Rotating Magnets

High temperature superconductors have the potential to enable high field magnet coils and superconducting machines with higher operating temperatures, which require much less cooling power. The challenge is delivering power to the superconducting circuit inside the cryogenic environment without burdening the cryogenic heat load with direct current leads. Several types of flux pump have been developed which have been shown to charge superconducting coils without direct conduction, using magnetic flux. This project involved designing a new type of flux pump which uses rotating permanent magnets to drive a superconducting switch rectifier circuit. There was uncertainty whether the principle would work, so the main objective was to determine whether this type of flux pump was possible to build. The dependence of the maximum load current on switch timing, rotor speed, magnetic flux gap and circuit resistance were investigated to optimise the device. The device was completed and shown to function as a flux pump, with a maximum load current of 15 amps. Experimental results showed a significant dependence on switch timing and rotor speed. There was some evaluation of the effects of magnetic flux gap and circuit resistance on performance. This new device offers significant opportunity for further investigation in future work.