A compact high-performance digital thyristor gate control set for line-commutated converters

Line-commutated converters are the logical choice in very high power AC to DC conversion as required in particle physics facilities. For instance, high-current thyristorized power supplies are used to drive the bending magnets of particle accelerators. The behaviour of such converters as far as distortion, time dynamics and precision are concerned, is closely related to the performance of the Thyristor Gate Control (TGC). In this work a compact high-performance optimum-speed TGC featuring a novel implementation of the digital ramp and threshold method is presented. Some digital simplifying strategies are introduced which allow the use of only one low-cost FPGA (Field Programmable Gate Array) as the digital core. The system developed is very flexible and can be easily configured to drive series or parallel connected converters.