The Research Of Real-time Technology In Tokamak Plasma Control Systems

The plasma control system is one of the most important components in a tokamak device.In modern tokamaks,the plasma control system is a sophisticated control system,which composed of numerous sub-systems and process various control algorithms.The real-time technology is one of the key technologies in a plasma control system.This thesis designs J-TEXT Real-Time Framework(JRTF),which is a flexible,multi-thread,and modular software framework according to the requirements of the plasma control system.The framework is developed in C/C++ language and can run on Linux,Windows,and QNX operation systems.In this framework,a number of C++classes provides functions such as real-time thread,data sharing,hardware interaction,EPICS IOC/Client,remote configuration,high-resolusion timer,logger and database support.This framework makes a clear separation between control algorithms and hardware/software operation,and the developers just need to focus on the control algorithms and implement their application with modular reusable components.This framework makes the development of real-time applications in plasma control more efficient,and makes the applications much easier to maintain and extend.The plasma control system is a hard real-time system,which requires good real-time performance of the opration system.In this thesis,we evaluate various real-time operation system,and finally choose the Linux based real-time system.Using RT-Preempt patch to turn the normal Linux kernel into a fully preemptable kernel,which could meet the requirements of the hard real-time tasks in plasma control.In addition,we research the tuning methods to enchance the real-time performance and stability of a real-time Linux system based on RT-Preempt patch.Detailed benchmark tests are conducted to evalutate the system,and the test results show that the real-time Linux system could achieve good performance in hardware interrupt latency,timer accuracy and stability,thread contex switch latency,etc.The new J-TEXT Plasma Control System(JPCS)is designed and implemented.In this paper,we develop new control systems for poloidal field pulsed magnetic power supply system in J-TEXT.The new control system is based on NI PXI platform and real-time Linux system,and the software of the control system is powered by JRTF.In addition,we design and realize the interlock system,which coordinates all the sub-systems and provides interlock protection functions.The interlock system is based on NI CompactRIO platform,and the software is written in Labview.Moreover,we research the reflective memory real-time network and design a multi-core,multi-thread,centralized computing frame of the plasma control system.The JPCS has beem deployed in J-TEXT in March 2017,and works well in experiments.The research results and engineering technologies in this paper could lay the foundation for advanced plasma control in the future.