Design and Implementation of Slow Conventional Controller for the ITER MCTB Quench Protection System

The magnet cold test bench (MCTB), the key facility of the ITER project, is mainly used for performance verification of superconducting magnets before on-site installation. As an important subsystem of the MCTB, the quench protection system (QPS) utilizes high-power DC switches and commutation technology to achieve rapid current interruption.This paper presents the design and implementation of the slow conventional control system in the QPS, which performs status monitoring and logic control on the key components, including the by-pass switch, vacuum circuit breaker, counter pulse circuit, and pyro-breaker during preparation and test operation. The hardware platform of the QPS takes the Siemens S7-1200 programmable logic controller (PLC) as its core. The software program is developed with TIA Portal, and the supporting human-machine interface (HMI) is programmed via LabVIEW.Real-time full-process data exchange between the PLC and upper HMI is realized through the open platform communications unified architecture protocol. The test results verify that the proposed system integrates the comprehensive status monitoring and logic control functions, runs stably and reliably, and satisfies the engineering application requirements of the QPS.