A Ray-Tracing Analysis of ICRH in Tokamaks

Power deposition profiles generated by Ion Cyclotron Resonance Heating （ICRH） in non-circular tokamaks are studied using a ray-tracing technique. The simulation results for the Experimental Advanced Superconductor Tokamak （EAST） D-shaped plasma are presented. It is indicated that the spatial distributions of plasma parameters （plasma density, species temperature, minority ion concentration, etc.） have an significant influence on the power deposition profiles. The findings may be highly useful to the planned plasma heating and experiments in EAST.     

Study of Liquid Phase Shifter for ICRF on EAST

A method of current drive with Ion Cyclotron Range of Frequency （ICRF） on Experimental Advanced Superconducting Tokomak （EAST） is described. A variety of liquid silicon oil heights in the phase shifter will bring the phase difference to the current drive. It is found that the current drive can be achieved by using the phase shifter. The liquid phase shifter is one of the impedance matching systems too.     

超高压线路近端故障的快速距离保护

提出了一种针对超高压线路近端故障的快速距离保护新算法.该方法利用积分算法响应速度快、计算工作量小的特点,基于微分方程模型,结合工频变化量原理,有效地实现了超高压长线路近端故障的正确快速动作.基于RTDS数模仿真平台,对500 k V线路的多种故障形式进行了数模仿真试验,验证了该算法在超高压线路近端故障时可靠快速的动作性能.     

Stability of linear multistep methods for delay integro-differential equations

This paper is concerned with the numerical solution of delay integro-differential equations. The adaptation of linear multistep methods is considered. The emphasis is on the linear stability of numerical methods. It is shown that every A-stable, strongly 0-stable linear multistep method of Pouzet type can preserve the delay-independent stability of the underlying linear systems. In addition, some delay-dependent stability conditions for the stability of numerical methods are also given.     

基于IGBT选型的整流器、逆变器损耗计算新方法研究

随着“双碳”概念深入人心,为满足企业对于节能减排、绿色发展的要求,以1 140 V/75 kW变频调速系统为研究对象,提出一种新颖的整流器和逆变器IGBT计算损耗方法,用于IGBT的选择和电力电子散热装置的设计。在实现过程中,考虑栅极驱动电阻和直流母线电压对损耗的影响,给出IGBT的导通损耗、总开关损耗、效率和结温的分析方法。基于IGBT损耗与结温的相互作用,得出IGBT结温曲线。并对IGBT进行了选择校核,仿真及实验验证了所提方案的正确性。     

考虑频率安全约束及风电综合惯性控制的电力系统机组组合

随着风电渗透率上升,电力系统惯性响应和一次调频能力下降,频率安全问题凸显,有必要在机组日前发电计划安排中考虑频率安全约束。依据电力系统频率安全要求,提出了考虑频率跌落最低值的频率安全约束构造方法。同时引入风电综合惯性控制使风电机组参与一次调频,在此基础上建立了考虑频率安全约束及风电综合惯性控制的机组组合模型。运用M语言动态控制多机频率响应模型进行Simulink仿真,并将其嵌入到改进粒子群优化算法中迭代求解。含风电的IEEE39节点系统算例结果表明,所提模型和方法能有效提升系统频率响应能力,保证系统安全运行。     

基于SLAM的虚实配准方法研究

研究和实现了一种基于SLAM技术的虚实配准方法,通过将SLAM分离为定位和构图,分别利用改进的pf做位姿估计和ukf进行位置估计,进而实现整个场景内目标的位姿计算,最终完成虚实配准。一定程度上解决了传统方法中存在的视域受限问题,并同时支持户内和户外应用,提高了增强现实系统的可用性。     

Convergence Results of One-Leg and Linear Multistep Methods for Multiply Stiff Singular Perturbation Problems

One-leg methods and linear multistep methods are two class of important numerical methods applied to stiff initial value problems of ordinary differential equations. The purpose of this paper is to present some convergence results of A-stable one-leg and linear multistep methods for one-parameter multiply stiff singular perturbation problems and their corresponding reduced problems which are a class of stiff differential-algebraic equations. Received April 14, 2000; revised June 30, 2000     

涂镀钢铁产品发展近况

随着带钢生产技术的日益进步,涂镀钢铁产品已由传统产品向具有高性能的新型产品发展,无铬钝化板、氟碳板、耐指纹板及自清洁板等应运而生.介绍了部分涂镀钢铁产品近期发展的概况,指出在发展过程中需要注意并加以解决的一些问题.     

MR智能阻尼器试验研究及径向基网络模型

制作了MR智能阻尼器，并在不同的位移，速度和电流输入情况下，对自制的MR智能阻尼器进行了性能试验研究，建立了MR智能阻尼器的径向基函数网络模型。结果表明：神经网络模型能精确的描述阻尼器正向和逆向工作特性，并且对液体沉降、液体磁响应时间、蓄能器刚度等因素的影响也能很好的解决。