摘要：针对直流电磁铁因形状特殊且不规则、磁性材料的非线性与分布性而导致电磁铁设计方法不完善、设计精度低的问题,提出了一种基于magnet的直流电磁铁的优化设计方法,重点分析了直流电磁铁的初步设计,包括设计要求、直流电磁铁的结构设计及线圈设计,以及基于magnet有限元分析软件的直流电磁铁的优化设计,包括线圈骨架材料的确定、端盖尺寸的优化、气隙长度的优化等。试验结果表明,应用该方法优化设计的直流电磁铁具有启动电流小、动作迅速、可靠性和耐用性高等特点。

摘要：利用专用的电磁仿真软件magnet对轴向双分裂和大容量等复杂干式变压器进行了不同运行工况下的磁场分析和验证。基于场路耦合法根据需要模拟的工况建立合适的2D或3D等效模型,并利用正确的等效电路和边界条件对变压器的运行工况进行有限元分析模拟,最终通过能量法或电压法得到相应工况下变压器的阻抗。实际测试结果表明该方法的计算精度可满足产品实际要求,可使用magnet对干式变压器的阻抗进行仿真计算和设计改进。

摘要：A new electromagnetic suspension model using a combination of high temperature superconductors (HTS) and copper conductors is proposed in this paper. A feasibility study showed that the magnets of our model can generate the 250 kg vertical suspension force. Three dimensional FEM and Design Sensitivity Analysis using the levitation gap length and cross sectional dimensions of the HTS magnets as design parameters were conducted to obtain the optimal shape of the cross section and the configuration of the HTS magnet. It was found that the gap length when optimized HTS magnet was used was much larger than that when copper conductor magnet was used, while the HTS coil volume was minimum, and the perpendicular field along the outer surface of the HTS coil was less than 0.12 T.

摘要：The KTX device is a reversed field pinch （RFP） device currently under construction. Its maximum plasma current is designed as 1 MA with a discharge time longer than 100 ms. Its major radius is 1.4 m and its minor radius is 0.55 m. One of the most important problems in the magnet system design is how to reduce the TF magnetic field ripple and error field. A new wedge- shaped TF coil is put forward for the KTX device and its electromagnetic properties are compared with those of rectangular-shaped TF coils. The error field B,I/Bt of wedge-shaped TF coils with 6.4 degrees is about 6% as compared with 8% in the case of a rectangular-shaped TF coil. Besides, the wedge-shaped TF coils have a lower magnetic field ripple at the edge of the plasma region, which is smaller than 7.5% at R=1.83 m and 2% at R=l.07 m. This means that the tokamak operation mode may be feasible for this device when the plasma area becomes smaller, because the maximum ripple in the plasma area of the tokamak model is always required to be smaller than 0.4%. Detailed analysis of the results shows that the structure of the wedged-shape TF coil is reliable. It can serve as a reference for TF coil design of small aspect ratio RFPs or similar torus devices.

摘要：This paper tries to build a multi-functional downhole nuclear magnetic resonance （NMR） fluid analysis laboratory that can evaluate fluid information in real time at reservoir conditions at a depth of several thousand meters. The aim is to monitor the pollution of the formation fluids and quantitatively evaluate NMR characteristics of the fluids. It focuses on the design of the structure and parameters of a sensor with zero stray fields. Two separate coils are designed to measure NMR characteristics of flowing or static fluids. A method is proposed to use the Bloch equation, to guide the optimization of the NMR sensor. Finally, the measured results confirm that the design is reasonable. There is a homogeneous static field （perpendicular to the axial direction） in the center of the sensor, and there are no stray external fields. The novel design of pre-polarization magnet improves the signal to noise ratio, while shortening the sensor length.

摘要：In order to study the technology on cyclotron design,and to carry out researches on the crucial parts including the main magnet,beam diagnostics and engineering technology to accomplish the experimental verification of the 100MeV high intensity cyclotron and to pave the way for further increasing the current of the proton beam,a series of work has been done in succession since 2004,which highlights the research,design and fabrication of some of the critical *** technical requirement for each part has been reached *** present,all the work has been integrated into a set of comprehensive device,CRM Cyclotron,which is actually a test stand for high intensity cyclotron *** report will lay emphasis on the following:the CRM Cyclotron design and fabrication of relevant equipment,magnetic field mapping and shimming,10—15mA H- ion source,experimental research on RF cavity and injection system,beam commissioning on the internal target system,etc.

摘要：高压输变电的发展要求换流变压器的性能不断提高,而附加损耗作为重要的设计依据,目前的商用软件无法提供相关数据,为此该课题组设计了基于magnet面向高压换流变压器计算瞬态电磁场及附加损耗的二维专用程序。为提高不同设计人员的接受程度,该程序的前处理技术提供添加材料属性功能,二维电磁铁的瞬态电磁场计算实例,采用Delaunay和直线内插法相结合的网格剖分方法,Visual Basic 6.0脚本和magnet混合编程,后处理技术采用VBscript脚本、Txt文本及MATLAB实现结果显示分析。对一台500 kV换流变压器模型的附加损耗及短路阻抗进行计算,计算值和实测值的最大偏差是4.1%,验证了该软件计算的准确性和有效性。

摘要：A novel digital implementation of speed controller for a Permanent magnet Synchronous Motor (PMSM) with disturbance rejection using conventional observer combined with Extended Kalman Filter (EKF) is proposed. First, the EKF is constructed to achieve a precise estimation of the speed and current from the noisy measurement. Second, a proportional integral derivative (PID) controller is developed based on Linear Quadratic Regulator (LQR) to achieve speed command tracking performance. Then, an observer is designed and its error is utilized to provide load disturbance compensation. The proposed method greatly enhances the PMSM performance by reducing the control signal variation as well as the disturbance. The speed control performance is significantly improved compared to the case when we have an observer acting alone. The simulation results for the speed response and variation of the states when the PMSM is subjected to the load disturbance are presented. The results verify the effectiveness of the proposed method.

摘要：将改进型非支配排序遗传算法(NSGA-Ⅱ)应用于无刷直流电动机优化设计中,缩短电机设计周期,提高电机设计智能化程度。以效率和功率密度最高为目标,构建了基于NSGA-Ⅱ的电机多目标优化模型,采用VS2010开发平台进行了优化软件的开发,进行了一台50 W无刷直流电动机的优化设计。采用有限元分析软件magnet验证了该算法在电机优化设计中的有效性。

摘要：国内高压直流输电系统的发展对高压直流换流变压器性能要求愈来愈高。在换流变压器设计过程中,附加损耗是一项重要的参考指标。笔者介绍了基于趋肤深度控制的三维实体模型网格分层剖分方法和磁损耗计算方法,使用magnet软件计算了一台换流变压器的构件损耗,并对国际基准模Problem 21B进行了验证性计算。基于Visual Basic 6.0编写了换流变压器绕组涡流损耗计算专用程序界面,通过VBScript与magnet连接,完成了绕组涡流损耗计算并与实测值比较,验证了其正确性。