高动态响应DC-DC Buck变换器边界控制与滑模变结构控制性能比较

通过引用边界控制大信号稳定性及提高系统动态响应理论，以DC-DC Buck电路为例，设计了二次边界控制及滑模控制的开关切换面。通过MATLAB／Simetrix仿真比较波形，验证了理论分析的正确性。边界控制理论适用于所有的非线性开关变换器电路，是一种简单有效的稳定性判定及提高动态响应的控制方法。     

一种驱动系统新型速度控制方案

通过对驱动系统中Ｉ－Ｐ控制言式的分析，提出一种新型的速度控制算法，该方案能够获得比较好的控制响应，仿真衣实验研究结果证实了该方案的有效性。     

基于模糊逻辑的交通信号控制

本文给出了一种采用模糊逻辑进行路口信号灯控制的方法。通过从路口检测器获取车辆信号，模糊规则对信号灯进行优化控制。对本方法进行了仿真模拟，给出了实验结果。     

自适应神经元控制在机器人手指关节控制中的应用

对机器人手指关节驱动用直线驱动器的位置控制提出了单神经元自适应控制方案。通过实验验证了控制方案的正确性，为机器人手指关节的位置控制提供了一种有效方法。     

水泵试验转速控制的研究

通过介绍水泵试验的恒速控制，讨论了三相异步电动机变频控制转速的一种实用方法。     

基于DSP和SA4828的电机控制SPWM的研究

为了克服单纯由硬件或软件产生SPWM在占用硬件资源、精度以及稳定性差的缺点，介绍了一种以SA4828为基础产出SPWM方法，并通过DSP来实现。试验结果表明，该方法占用硬件资源少、精度高、稳定性好。     

叠加载波相移SVPWM调节控制方法研究

叠加载波移相空间矢量PWM(SVPWM)多重叠加法是特大型逆变器发展方向之一，本文推导了载波相移SVPWM电路输出电压谐波与移相角的关系，给出了最佳移相角公式；提出了两种控制方案并比较其优缺点。通过对某地空导弹60KVA静止变频器国产化实验证明了：通过合适的输出滤波参数设计，分步调节变换器的脉宽也是一种可行的方法。     

非线性励磁控制设计方法

非线性系统的几何结构理论在近十几年内有了很大发展，并已被应用到多机系 统发电机励磁控制的设计中。本文在此基础上，通过引入一个附加的状态变量 ，用于解决非线性励磁控制律中功角不易测定这一问题，给出了一种易于实现 的非线性励磁控制规律。通过一个单机无穷大实验系统的动态模拟实验，表明 该方法不仅有效地改善了系统的动态响应，而且显著地提高了系统的静态稳定 极限。     

无速度传感器矢量控制系统的一种控制方法

介绍了无速度传感器矢量控制系统中SVPWM的一种控制方法，并对实际电动机进行了控制。通过实验取得了令人满意的结果。     

改进控制线路确保电开水器沸腾后能及时跳闸

本文通过分析大型电开水器水温控制的不足之处，介绍了一种改进后的温度控制线路，确保了电开水器沸腾后能及时跳闸，该方法简单，有效，经济，值得在已使用的产品中推广。     

Stability of large-scale coal-fired MHD channels

Stability of large-scale coal-fired MHD channels is studied by (1) linearized stability analysis, and (2) time-dependent 1-D analysis. The channel length is 15 m with 600 electrode pairs, and the output power ranges from 220.6 MW through 258.7 MW. Linearized stability analyses show that the Faraday channels operated with fixed loading resistance are stable, whereas the two waves of u and u–a (u, a: gas and sound velocity) become unstable in the Faraday channel with fixed loading factor. Two waves of u and u–a are unstable in the diagonal channel with fixed loading current and the u + a wave becomes unstable in the diagonal channel with fixed electrode current. Time-dependent one-dimensional analyses indicate that the Faraday channels with fixed load resistance are smooth without growth of fluctuation. The diagonal channels with fixed electrode current are smooth with no fluctuation, though the linear theory indicates that the u + a wave is unstable. The diagonal channel with fixed load current suffers large disturbance along the latter half of the channel, being consistent with the linearized analysis which indicates that the u - a and u waves are unstable.     

基于概率路线图法的窄道采样与轨迹优化

提出一种结合莱维飞行和概率路线图法(Lévy-probabilistic roadmap, LPRM)的路径规划算法。将莱维飞行方法应用于窄道采样,障碍物中的随机点通过莱维飞行走至自由空间,并延长碰撞测试来确保采样点位于窄道内,提升狭窄区域的采样质量与效率;为避免大量无效点的生成,在采样前先对地图进行预处理,膨胀障碍并对其进行边界提取,根据边界信息计算狭窄区域采样点数量,保证了全图采样的合理分布;进一步考虑移动机器人的实际工作情况,采用分段贝塞尔曲线对路径轨迹进行优化使其符合运动学约束,提高移动机器人的机动性。仿真实验在不同环境地图下对比了LPRM、传统概率路线图(PRM)和桥测试3种算法,结果表明LPRM算法相较两者在单一窄道环境下规划效率分别提升35.1%和32.2%,在复杂环境下其规划效率分别提升32.9%和15.5%,且提前400和100个采样点达到收敛,规划效率和成功率显著提高,总体耗时更短、路径更优,能减少移动机器人本身的能耗,提高整体工作效率。     

A novel bi-directional high-gain DC-DC converter with optimum number of components

Most emerging applications of battery energy storage systems, fuel cells, and unified power supply (UPS) applications require essential bi-directional power capability with a high conversion ratio. It supports the integration of the high-voltage DC-bus with an energy storage unit or fuel cell. In order to meet this requirement, this paper proposes a novel nonisolated high-gain DC-DC converter with bi-directional power flow capability. This converter is configured with a hybrid structure with a combination of the switched capacitor (SC) and switched inductor (SI) techniques. Moreover, this converter can attain extreme voltage gain with less number of semiconductors and passive components. As a result, the converter cost gets reduced and achieves a wide range of voltage gain at a lesser duty ratio. Furthermore, steady-state analysis and performance of the proposed topology and its characteristics were presented in this paper. Additionally, a detailed comparative analysis was presented with the most recent literature. Finally, a 500-W experimental prototype has been fabricated to authorize the performance, feasibility, and analytical waveforms with experimental results.     

New soft-switching current source converter for photovoltaic power system

This paper proposes a soft-switching CSI for a photovoltaic power system which has an H-type switched-capacitor module composed of two semiconductor switches, two diodes and an L-C resonant circuit. The operation of the proposed system was analyzed using a theoretical approach with equivalent circuits and verified by computer simulations using a simulation program with integrated circuit emphasis and experimental work with a hardware prototype. The proposed system could be effectively applied to the power converter of a photovoltaic power system interconnected with an a.c. power system.     

Constructions and characteristics of a tiny piezoelectric linear motor using radial mode vibrations

A tiny ultrasonic linear motor with a structure has been developed, and various shaft materials were tested in the motor in order to improve its dynamic properties. We found that the shaft material has direct influence on efficiency, reliability and quality of the motors and their dynamic properties and is crucial to the achievement of high motor performance. The use of shafts of various materials such as stainless steel, stainless steels coated with DLC (Diamond Like Carbon) and PTFE (Teflon), a Pyrex, and a graphite, can make it possible to improve dynamic properties of the motors over a wide range of tribological conditions. In a motor with a stainless steel shaft coated with DLC driven at 44 kHz, its velocity was 4 mm/s with a force of 75 mN. When a motor used the Pyrex shaft was used a force of 110 mN was attained at 51 kHz. Thus the maximum force produced by a motor with a graphite shaft is estimated to be 120 mN with a velocity of 8 mm/s. We found that graphite has the appropriate surface conditions and directional texture to promote the linear motion of the moving element. Finally, the use of a cap resulted in significant improvements in the stability of the motor’s operation. Motor with graphite and Pyrex shafts were found to exhibit very stable operation and improved dynamic characteristics.     

基于LabVIEW的SVC监控系统的研制

采用分布式模块化结构开发了静止无功补偿器(SVC)的控制系统,它由监控、数据采集、控制调节及触发单元通过串、并行通信方式构成。监控单元在LabVIEW环境下采用虚拟仪器技术设计,操作控制可通用SVC、显示记录运行信息、设置工作参数等。经静止无功补偿模拟试验系统检验、运行证明控制系统设计正确合理。     

磁体外部片状均匀磁场区的构建

在磁体外部构建片状均匀磁场区域，是磁体设计所面临的一个全新问题。文中提出了一种混合逆数值算法，以探索这种设计的可行性。混合逆数值算法是一种两步算法，包含直接矩阵反演求逆和二次规划两个步骤。文中对该数值算法进行了详细的描述，并用它成功地找到一种多磁块组合的单边永磁磁体结构。经通用有限元计算软件仿真和对磁体模型的测量表明，这种磁体结构能够较好地在磁体外部一侧构建片状均匀磁场区。用单边永磁磁体在磁体外部构建片状均匀磁场区的实现，为开展单边均匀场常规磁共振成像系统研制等科学研究打下了坚实的基础。     

Hierarchical decentralized autonomous control in super‐distributed energy systems

This paper deals with a decentralized autonomous control strategy of a super‐distributed energy system with a hierarchical structure in order to reduce the complexity of control. In this paper, distribution systems are assumed to be composed of multiple small‐scale power systems in which many customers with dispersed generators exist. A small‐scale power system can be considered as a unit with a generator state and a load state, or as a customer with dispersed generators. Control components of small‐scale power systems are interconnected with each other and are used to operate distribution systems. An expanded decentralized autonomous control method for a super‐distributed energy system with a hierarchical structure is proposed on the basis of the Hopfield neural network. It is demonstrated that super‐distributed energy systems with a hierarchical structure can be controlled autonomously by applying the proposed method. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

对各偏好下正价格的CAPM均衡的讨论

对各偏好下的正价格的CAPM均衡分4种情况进行了讨论,分别是多元CAPM均衡、负指数效用函数下的正价格CAPM均衡、线形效用函数下的正价格CAPM均衡、平方效用函数下的正价格CAPM均衡。通过证明得到了多元CAPM均衡的1个定理。在LEVY的讨论基础上,绕开复杂的积分,给出了负指数效用函数在求解市场组合的详细过程。对于平方效用函数下的正价格CAPM均衡,由2个引理可知,投资者的偏好为二次效用函数时,具有均值方差偏好,并且其投资组合为切点组合。     

Ferroelectric Based Photonic Crystal Cavity by Liquid Crystal Infiltration

A novel type of two-dimensional photonic crystal is investigated for it optical properties as a core-shell-type ferroelectric nanorod infiltrated with nematic liquid crystals. Using the plane wave expansion method and finite-difference time-domain method, the photonic crystal structure, which is composed of a photonic crystal in a core-shell-type ferroelectric nanorod, is designed for the square lattice and the hexagonal lattice. It has been used 5CB as a photonic crystal core, and LiNbO₃ as a ferroelectric material. The photonic crystal with a core-shell-type LiNbO₃ nanorod infiltrated with nematic liquid crystals is compared with the photonic crystal with solid LiNbO₃ rods and the photonic crystal with hollow LiNbO₃ rods.