Design Progress of the ITER Plasma Control System

A. Winter, G. Ambrosino, D. Humphreys, J. Lister, G. Raupp, E. Schuster, J. A. Snipes, W. Treutterer, M. Walker and L. Zabeo

IAEA Technical Meeting on Control, Data Acquisition and Remote Participation for Fusion Research

Hefei, China on May 6-10, 2013

The ITER Plasma Control System (PCS) is a fundamental component of the ITER Control, Data Access and Communication system (CODAC). It will control the evolution of all machine and plasma parameters that are necessary to operate ITER throughout all phases of the discharge. A Conceptual Design Review was held in November 2012 and this paper will summarize outcome of this review with focus on the challenges identified and the approach taken by the CODAC section to design a system architecture which is capable of meeting them. The preparatory work for the conceptual design review has been carried out by a worldwide collaboration of plasma control experts coordinated by the IO as well as the ITPA integrated operating scenarios group, which focused primarily on the physics requirements for the PCS (related mainly to diagnostics and actuator requirements for control functions). The control experts drafted the functional specification and initial collection of use cases for operation, event detection and exception handling and performed an initial assessment of the requirements with regard to a possible framework architecture. This paper will focus on the functional specification and the present state of event handling and system architecture; the physics requirements are covered in a companion paper. It is within the scope of activities of the ITER CODAC section to design the system architecture of the plasma control system and implement the control strategies and algorithms provided by the ITER plasma operations directorate. This paper will give an overview of the initial results of the development of the system architecture. ITER CODAC will rely on strong fusion community support in order to develop an appropriate real-time framework. This framework should not only support the implementation of plasma control strategies with the extensive exception handling and forecasting functionality foreseen for ITER, but also integrated commissioning and sophisticated machine protection functionality (e.g. first wall protection). These are novel requirements not or only partially addressed by existing plasma control systems. The paper will summarize the key challenges and present the implementation strategy until initial ITER operation in late 2020. A second cornerstone in the implementation strategy is the development of a powerful simulation environment to design and verify control strategies, event handling and interaction with the ITER Central Interlock System. One objective of this simulation environment will also be to facilitate the efficient implementation of the actual ITER Plasma Control System. Such an environment is currently under contract and this paper will also briefly summarize the developments during the past two years.