Progress in the ITER Plasma Control System design

The ITER Plasma Control System (PCS) controls all aspects of the ITER plant necessary to achieve the pulse scenario. This includes control over the magnets, fueling and auxiliary heating systems, but also many functions that monitor plasma operation limits and instabilities. This paper will describe how the ITER PCS is designed and report on the design status, highlighting some of the critical functions and design issues. The main functions such as magnetic, fueling and heating control and initial disruption avoidance are well underway, being detailed in the system engineering database (PCSDB) and being implemented in the PCS simulation platform (PCSSP) in Matlab/Simulink which jointly provide the PCS design description. The PCSSP is also key in permitting design assessment by simulating and testing the multitude of functions which comprise the PCS. We illustrate the overall PCS architecture with an example use-case: the complex, multi-task control scenario required to manage plasma operation with the Electron Cyclotron Heating (ECH) system. This has taken on even greater importance given the recent ITER organization re-baseline proposal which requests a very significant increase in the installed ECH power, doubling from 20 MW to 40 MW for the first operation phase, Start of Research Operations, and increasing further up to 67 MW for the deuterium–tritium campaigns. The PCS design in this case requires a clear breakdown into manageable sub-functions which focus on parameter monitoring, actual control, and the complex interface between the ITER PCS and the ECH system itself. Control functions include not just the control of the ECH power, but also related tasks, such as the control of [Neoclassical] Tearing Modes. The implementation requires the design of actuator management functions which efficiently manage the potentially conflicting actuation requests from PCS functions to the ECH system, as well as the exception handling functions that provide appropriate reactions to deal with off-normal events during plasma pulses. • This work provides an update on the ITER PCS design to ensure successful operation. • A brief overview of the system engineering design approach is presented. • Electron Cyclotron Heating system upgrade in ITER’s baseline is highlighted. • The new updates enhance power capacity for plasma heating and instability control. • Simulation results show PCS design complexity and flexibility in multi-control tasks.