The Design Of EAST Superconducting Magnet Temperature Monitoring System

The monitoring of superconducting magnet temperature is one of the most significant strategies to ensure the safety of the instruments’operation during the experiments of the Experimental Advanced Superconducting Tokamak.The existing monitoring system has already operated for many years,and the whole system is facing the serious problem of aging and damages,which decreases the stability and reliability of the monitoring system.Therefore,it is necessary to establish a new,more stable and more reliable superconducting magnet temperature monitoring system to ensure the operation safety of EAST during the experiments.Before establishing the monitoring system,based on the analysis of the functional requirements of the temperature monitoring system for superconducting magnet system,the overall design of the system is performed based on PLC,LakeShore Model 224 and LakeShore Module 240-8P.According to the overall design,the nitrogen system is established by the Siemens S7-300 series PLC and the LakeShore Module 240-8P,in addition,LakeShore Model 224 instruments are used to update the helium system and the construction of two hardware systems is finished.Then the communication method of two systems are decided,according to the required functions of the hardware system,the PLC program of nitrogen temperature area monitoring system and the hardware configuration setting of helium temperature area monitoring system are finished.PLC will realize the communication with the computer by OPC and LakeShore monitor will realize by Lab VIEW program(VI).After hardware system establishment,software LabVIEW is utilized to program and completes the program design of function modules,realize the nitrogen temperature area monitoring system’s functions of the real-time monitoring interface,alarm interface,coil resistance monitoring interface,historical data query interface,upload database;and program to realize the real-time monitoring interface,alarm interface and uploading database function of helium temperature area monitoring system.The functions of every subsystem module are verified and the stability and reliability of the system are observed by the steps of the fundamental function test,communication test,black box test,and tabletop test before EAST’s experiments.The new EAST superconducting magnet temperature monitoring system is already operated until now,the operating result shows that the new system can realize the anticipated functions,the stability and reliability are promoted a lot,the new system can satisfy the safety requirements of EAST operation.