Development of a real-time impedance matching system for ion cyclotron resonance heating in experimental advanced superconducting tokamak

• Published in: Review of scientific instruments Vol. 95; no. 2
• Main Authors: Chen, Q Q, Liu, L N, Qin, C M, Zhang, X J, Mao, Y Z, Yuan, S, Zhang, W, Yang, H, Wang, L, Cheng, Y, Zhang, K, Guo, Y Y, Sun, Y P
• Format: Journal Article
• Language: English
• Published: United States 01.02.2024
• ISSN: 1089-7623
• DOI: 10.1063/5.0187113

To achieve stable operation of an ion cyclotron resonance heating (ICRH) system in the Experimental Advanced Superconducting Tokamak (EAST), a real-time impedance matching system needs to be established to respond to antenna load variation during long pulse discharges. A new impedance matching method based on capacitors was proposed in this study. By considering the reflected voltage of the transmission line as the feedback parameter, the real-time impedance-matching system can quickly control the motors based on a programmable logic controller to determine the minimum reflection voltage. A real-time impedance matching system was successfully used on the test platform in the laboratory and on the ICRH system in EAST. A significant result is that we can match the variable impedance within 1 s by suitably adjusting the motor controller to ensure high-power and long-pulse operation of the ICRH system to satisfy the requirements of the EAST experiment.