The Design on Pulse Distributor and its Online Status Diagnosis for ITER PF ac/dc Converter

The International Thermonuclear Experimental Reactor (ITER) poloidal field (PF) ac/dc converter operates in four quadrants to provide the control of current necessary to PF coils for plasma initialization and the plasma shape control. The technical details for thyristor triggering of high-power ac/dc converter lay the foundation for the regular operation of ITER PF ac/dc converter. With the characteristics such as high power, complex operating modes of ac/dc converter, the synchronization, reliability, and high security have to be critically concerned in the pulse distributor design. In this paper, a pulse distributor is designed to convert the optical signal to high current electrical trigger pulse with less than 1-μs rising time, thereby triggering the paralleled thyristors reliably and isolating 20-kV voltage from the converter unit to controller. Furthermore, the signals of crucial status are online acquired and encoded, then transmitted to controller by optical fiber, thus implementing the online status diagnosis to guarantee the safety operation of ITER PF ac/dc converter. The pulse distributor has been experimented in ITER PF ac/dc converter and all functions have been effectively verified.