Research and development of the high-power high-current polodial field converter module

This paper presents the analysis, design and test of the high-power high-current Poloidal Field (PF) converter module, which will be used in the PF coil power supply system of the International Thermonuclear Experiment Reactor (ITER) superconducting tokamak. Due to the high current rating and special Fault Suppression Capability (FSC) requirement, the number of paralleled thyristors on each arm is determined 12 based on the type selection analysis of thyristor and high-speed fuse. A large amount of parallel thyristors will give rise to significant difficulties in the current sharing design. So a novel method based on inductance matrix is proposed for the current sharing design. To ensure the structural strength under the worst fault condition, a new structure design based on the framework structure is applied in the bridge. Corresponding tests are performed and the test results indicate that the PF converter module is of good current sharing ability and high dynamic characteristic, which can fully satisfy the design requirement. The design method and structure of the PF converter module can provide a reference for the research and development (R&D) of high-power high-current thyristor converters.