Methodology for the deployment of ITER Fast Plant Interlock system. Use case: ITER Poloidal Field and Central Solenoid coil's power converter protection system

Abstract

Interlocks are the instrumented functions of ITER that protect the machine against failures of the plant system components or incorrect machine operation. Regarding I&C, the Interlock Control System ensures that no failure of the conventional ITER controls can lead to severe damage of the machine integrity or availability.ITER Interlock System incorporates several Plant Systems that require response times below 1 ms to perform the required protection actions. Systems like the Coil Power Supply System (CPSS), Ion Cyclotron Heating and Current Drive (ICH&CD), Neutral Beam Injectors and Current Drive (NBI&CD), Disruption Mitigation System (DMS), and others. ITER developed a methodology to create the fast architecture for the Plant Interlock Systems (PIS) that ensures high integrity on the final solution.The functional safety standard IEC 61508 has been used to define a methodology for the configuration of the RIO (Reconfigurable Input/Output) platform from National Instruments (compactRIO platform).This work describes in detail this methodology, valid for most cases just selecting different input/output signal types to be handled and choosing different numbers of interlock functions to be performed. In addition, this paper describes the development of the interlock system for the ITER Poloidal Field and Central Solenoid Coil’s Power Converter protection, a special case due to its unique configuration, the most complex implemented up to date. The development of this special case “puts to a test” the methodology’s approach. Finally, the discussion of the fitness of the methodology and the performance of the system is presented.