Contents lists available at ScienceDirect Fusion Engineering and Design journal homepage: www.elsevier.com/locate/fusengdes Assessment of controllers and scenario control performance for ITER first plasma Michael L. Walker a, ⁎ , Anders Welander a , David Humphreys a , Giuseppe Ambrosino b , Gianmaria De Tommasi b , Sylvain Bremond c , Peter De Vries d , Joseph Snipes d , Fernanda Rimini e , Wolfgang Treutterer f a General Atomics, San Diego, United States b Consorzio CREATE/Università di Napoli Federico II, Napoli, Italy c CEA, IRFM, 13108, St. Paul-lez-Durance, France d ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067, St. Paul-lez-Durance, France e CCFE/Fusion Association, Culham Science Centre, Abingdon, OX14 3DB, United Kingdom f Max Planck Institute for Plasma Physics, Boltzmannstr. 2, 85748, Garching, Germany ARTICLE INFO Keywords: ITER PCS Design Assessment ABSTRACT The ITER Plasma Control System (PCS) will control ITER plasma operation, with performance requirements much more stringent than existing fusion devices. We report on assessment of control algorithms and control scenarios comprising the prototype ITER PCS design, which is the starting point for development of the final design for first plasma operation. The scenarios assessed include commissioning of magnetics and gas systems using the PCS and the first plasma scenario, which includes neutral gas prefill, plasma breakdown/burnthrough, and initial evolution of equilibrium and plasma density. Plant systems involved in first plasma control include ECH, PF and CS coils and power supplies, gas valves, and magnetic, neutral pressure, and electron density diagnostics. Assessment involves simulation of an ITER PCS model connected in feedback with an ITER plant model, both executing in the Plasma Control System Simulation Platform (PCSSP). PCSSP is presently under- going upgrades as part of PCS development to provide support for algorithm development, PCS architecture evaluation, and control performance assessment. In particular, PCSSP provides general methods for extensive testing of performance in the face of multiple adverse events, such as plasma instabilities growth, disruptions, or plant system faults. 1. Introduction A task to develop an ITER Plasma Control System (PCS) final design for First Plasma (FP) was begun in October 2017 and is scheduled for completion in March 2020. Although the target of this initial work is FP operation [1], the developed PCS architecture must be extensible to future ITER operation phases. The PCS has performance requirements much more stringent than existing devices, since the consequences of control failure (after initial FP operation) can be severe. This issue leads to the requirement that all control required for ITER operation be va- lidated in simulation prior to use in plasma operation. A part of this required validation is the assessment of controllers and control scenarios used by the PCS to support ITER plasma operations. We report here on the progress in development of the methods for as- sessing scenarios, controllers, and integrated control processes delivered in the course of the PCS design. Multiple studies (e.g. [2]) have verified that the startup scenario planned for ITER can provide successful plasma initiation under a variety of assumed conditions and modeling assumptions. The objective of the current assessment task is to demonstrate that the PCS final design for FP provides the operational capability needed to reliably perform this initiation and subsequent plasma control. 2. First plasma control scenarios Two different models representing two different ITER reference scenarios are considered in this work. A vacuum commissioning model is used to assess planned activities for commissioning of the PCS. Actuators available for use during PCS commissioning are the gas valves, poloidal field (PF) and central solenoid (CS) power supplies (PS) https://doi.org/10.1016/j.fusengdes.2019.03.050 Received 27 September 2018; Received in revised form 18 January 2019; Accepted 8 March 2019 ⁎ Corresponding author. E-mail address: walker@fusion.gat.com (M.L. Walker). Fusion Engineering and Design xxx (xxxx) xxx–xxx 0920-3796/ © 2019 Published by Elsevier B.V. Please cite this article as: Michael L. Walker, et al., Fusion Engineering and Design, https://doi.org/10.1016/j.fusengdes.2019.03.050