Design and Experiment of Thyristor Drive Circuit for CRATF Superconducting Magnet Power Supply

The high-power converter for the Comprehensive. Research Facility for Fusion Technology (CRAFT) magnet power supply has a DC output current of 30 kA and a voltage of 250 V. The use of good performance drive circuit can make the thyristor work in a more ideal switching state, shorten the switching time, reduce the switching loss, which has an important significance on the operation efficiency, reliability and safety of the converter device, which makes the design of the drive circuit more important. In this paper, for the requirements of CRAFT superconducting magnet power converter, a set of strong triggering final drive circuit can be designed for the thyristor of the converter to meet the requirements. After receiving the trigger signal from the control system, the final drive circuit outputs a strong departure current with a peak value of about 4A, a current rise rate of about 1.15A/μs, and a gate current plateau value of about 0.8A, which can turn on the thyristor quickly and stably.