先进偏滤器位形控制算法研究及控制程序开发

According to theoretical analysis and experimental results, the advanced divertor configuration is expected to be applied to the ITER and fusion reactor in future, as it can effectively reduce the heat load at divertor target plate. However, the desired orientation and distance between two X-points of the advanced divertor configuration have enormous influence on the magnetic flux expansion, broadening of heat flux profiles, reflux of impurities and the operation of detachment divertor. So the advanced divertor configuration control (especially X-points control) is very important for the operation and the study on physical mechanism of the advanced divertor..HL-2M is being built at SWIP, in which the operation of the various advanced divertor configuration is compatible with the standards divertor by optimizing the layout of poloidal field coil system. It can provide a good platform for the study of the advanced divertor. So the accurate control algorithm of the advanced divertor configuration has become the indispensable part of the control system of HL-2M. It is also the base of maintain advanced divertor and in-depth research on physics..This project aims to develop the accurate control algorithm of the advanced divertor configuration. The main configuration parameters, such as the center of two X-points, the desired orientation and distance between two X-points, can be tuned by this control algorithm, as well as adjust the magnetic flux expansion and the position of strike point. Considering the influence of the plasma motion on the circuit equations, the control program will be developed based on the configuration control algorithm. The reliability of this program will be test by the analog signal. In addition, the feasibility of transformation between different advanced divertor configurations will be also explored with this control algorithm.

理论研究及实验结果表明先进偏滤器位形能够有效的降低偏滤器靶板的热负载，有望应用到ITER及未来聚变堆中。我院正在建造的HL-2M装置，通过优化极向场线圈布局，具备兼容运行标准偏滤器和多种先进偏滤器位形的能力，为开展先进偏滤器研究提供了良好的平台。然而从先进偏滤器的实验结果及模拟分析发现，两个X点连线的距离及方向等参数对磁通展宽、热流分散、杂质反流、脱靶偏滤器的运行都影响极大。因此，先进偏滤器位形精确控制算法，已经成为HL-2M控制系统的重要组成部分，也是保障先进偏滤器稳定运行以及开展物理研究的基础。.本项目旨在研发先进偏滤器位形精确控制算法，实现两X点中心、X点连线的距离及角度的控制，以及磁通展宽和打击点位置的调整；以位形控制算法为基础，考虑等离子体运动对回路方程的影响，开发等离子体控制程序。并通过模拟仿真验证控制程序的可靠性；此外，利用X点控制算法探索不同先进偏滤器位形相互转化的可行性。

国际上以DIII-D和TCV、NSTX等装置为代表，开展了大量先进偏滤器（雪花偏滤器为主）的实验，获得了稳定的先进偏滤器位形，研发了各种各样的先进偏滤器位形的控制算法并掌握了相关的控制技巧。这些控制算法各有优缺点，仍处在快速发展中，但需要进一步的改进，以便实现雪花等先进偏滤器位形的精确控制，从而开展先进偏滤器物理相关的深入研究。在国内，EAST装置开展了准雪花偏滤器位形的初步实验运行；但对于先进偏滤器位形精确控制的相关研究还处于空白阶段。我院正在建造的HL-2M装置，通过优化极向场线圈布局，具备兼容运行标准偏滤器和先进偏滤器的能力；并且各个线圈具备独立供电能力的极向场线圈位于环向场线圈和真空室之间（与等离子体距离较近），有利于利用线圈对等离子体进行灵活控制；因此，HL-2M为开展雪花偏滤器的研究提供了良好的平台。此外，研发先进偏滤器位形精确控制算法，已经成为HL-2M控制系统研发的必不可少的组成部分，也是保障先进偏滤器稳定运行以及深入开展物理研究的基础。.本项目的研究目标是研究先进偏滤器位形的精确控制算法，开发相应的控制程序，并通过模拟仿真验证控制程序的可靠性。.本项目通过研发先进偏滤器位形识别算法，解决了先进偏滤器的主要参数（两X点中心、间距、角度等）的识别问题；通过建立PF线圈电流对位形变化（主要X点变化）的响应模型，考虑等离子体运动对等离子体-电源回路方程的影响，推导先进偏滤器位形控制算法并开发相应程序，解决了先进偏滤器位形X点的精确控制的关键问题，并利用该程序，实现了不同先进偏滤器位形之间的平稳的转换。.这些研究结果有助于HL-2M开展先进偏滤器控制相关的研究，同时也为国内托卡马克装置上进行先进偏滤器运行以及相关物理机制的研究奠定基础，从而加快国内先进偏滤器研究步伐，为我国未来聚变堆的运行提供支持。