Build Charging Database of Linear-Motor Type Flux Pump and Analyze the Influence of DC-Bias Field Using Fixed Step Size Search Algorithm

The linear-motor type flux pump is a wireless DC power source for high-temperature superconducting coils, which is compact in size, efficient in energy use, fast in output control, etc. It consists of three major parts: DC windings, phase windings and iron circuit, which generates a DC-bias AC travelling wave in its airgap. In theory, there are three controllable parameters such as DC-bias field, amplitude of the AC travelling wave, and the field frequency (travelling speed). By changing those parameters, we change the applied fields and its DC output current into superconducting coils. For studying the impact of those parameters on its DC output, this paper uses a fixed step algorithm to collect the current charging data, by automatically controlling the flux pump device, and then establishes an output database. By using this algorithm, we have searched out the maximum pumped current and analyzed the impact of the three parameters. We have also found out that, in order to get maximum current output, the value of the DC-bias field should be close to the amplitude of AC magnetic field.