Development and status of high-voltage power supply and integrated control system for KSTAR ECH system

Abstract

Korea Superconducting Tokamak Advanced Research (KSTAR) is planning to install an auxiliary heating device comprising six electron cyclotron (EC) systems with a total of 6 MW of radiofrequency (RF) output. Two EC systems were operated in the 2019 KSTAR campaign. To compensate the shortcomings identified during the operation of the previous two systems, the power supply was upgraded and a new integrated control system was developed. A power supply is a device that affects the RF beam quality generated by the gyrotron of an EC system and ensures efficient operation. Features such as real-time operation, a crowbar system, and a redundancy module were added to the upgraded power supply. An integrated control system is an important device that protects a gyrotron and supports stable operation. The overall structure of the integrated control system was changed to enable real-time operation, and functions such as retrigger and shot-information were added. In the 2020 KSTAR campaign, a new EC system including the upgraded power supply and the new integrated control system was added, and a total of three EC systems were operated. The new EC system was successfully employed at KSTAR. In this paper, we explain in detail the upgraded power supply and the new integrated control system and show and discuss the results of their application to the 2020 KSTAR campaign.