Design and Simulation Analysis of Cryogenic System of HTS Synchronous Condenser Rotor

The superconducting coil with high current carrying capacity and DC resistance-free characteristics is used to replace the copper coil on the traditional motor rotor, which can greatly improve the air gap flux density and power density of the motor. This paper introduces the cryogenic system of a high-temperature superconducting (HTS) Synchronous Condenser rotor. The HTS magnet in the rotor is cooled centrally by embedding Gas-Helium pipes in each coil, and cold rings are set at both ends of the magnet for temperature partitioning to reduce the temperature influence of other components on the magnet. According to the theoretical formula of heat transfer, the total thermal power of the cryogenic system in the rotor was calculated, and the Gas-Helium input parameters required by the rotor are deduced. Subsequently, the temperature distribution of the HTS coils inside the rotor was simulated by the fluid thermodynamic method. The simulation results show that the HTS coils and cold rings are separately cooled to 27.05 K and 36.35 K by the externally introduced 25 K Gas-Helium, and the temperature difference of the coils is only 0.2 K, which shows the reliability of the cryogenic system in the HTS synchronous condenser rotor.