Status of the ITER ECRH&CD control system development

Abstract

The ITER ECRH&CD system is designed to inject 20 MW of millimetre-wave at 170 GHz into the vacuum vessel. The system is composed of many sub-systems, namely High-Voltage Power Supplies (HVPS), Gyrotrons, Transmission Lines (TL), Ex-vessel Waveguides (EW), Launchers. It is the role of the EC Plant Controller (ECPC) to integrate all the Sub-system Control Units (SCU), to prepare the system for operation and to execute the real-time requests coming from the plasma control system. Plant level protections are also implemented by the ECPC, in charge of ensuring the safe operation of the plant, while optimizing the power availability. While control and protection functions are always pushed to the lower possible controller able to implement them, the operational requirements and flexibility of the system make it impossible to fully segregate many functions, since each gyrotron is connected to at least two different launching mirrors. To simplify the SCUs’ development and to respect the responsibility boundaries imposed by the procurement strategy, all the functions involving more than one sub-system are implemented in the ECPC, which exposes a single operational interface towards the ITER Central I&C. The status of the control system development is presented in this work.