加强华北电网输电网络的研究分析

分析华北地区的负荷特点表明，随着华北电网容量的不断增加，华北电网的建设已由原来的联合型向紧密型方向发展，因此根据高速增长的用电需求及当前电网发展的新特点提出了多项建议，强调指出结合华北地区的具体特点加强电网输电方式的研究迫在眉捷。     

电网在线安全稳定分析和预警系统

针对电网运行安全稳定分析由离线分析向在线化发展的要求，将电力系统的静态安全分析、电压安全分析、暂态安全分析和继电保护定值校核等子问题进行在线综合研究，建立了一套完整的基于能量管理系统和调度员培训模拟系统数据平台的在线综合安全预警及协调预防控制分析系统，并提出了电网在线安全稳定分析和预警安全评估体系，从综合安全预警的角度划分了电网的状态。该系统已在江西电网中得到应用，为运行人员由离线分析向在线分析、由“经验型”调度向“智能型”调度转变提供了良好的平台和辅助工具。     

商洛电网运行方式的优化研究

以2006设计水平年为依据，采用电科院综合程序(WPSASP)作为计算工具，用大网(陕西电网) 小网(商洛电网)的数据模式建立了商洛电网2006年的各种典型运行方式，详细研究了商洛电网在运行方式上可能出现的诸如变电站供电方案选择、110kV电网开环点的选择以及向外省电网送电的可行性等一些问题，采用退火选择遗传算法对商洛电网进行了无功优化计算，计算结果表明该算法能够在手工调节潮流的基础上，进一步优化电网潮流，具有明显的降损及改善电网电压质量的作用。     

不同等值方法对辽宁电网短路电流计算的影响研究

提出了一种新的电网等值思路,即骨干电网等值法,它通过配网向主网等值和主网向骨干电网等值两步来简化处理待等值电网。基于PSD-BPA软件搭建东北-华北地区数据库计算短路电流水平,比较采用不同等值方法研究对辽宁电网主网不同电压层级短路电流的影响。研究了不同等值方法的时间鲁棒性和待等值电网的电气参数分布对本地区电网的影响。     

京广电铁谐波对河南电网并联无功补偿电容器组影响的计算与分析

电气化铁道的电力机车是流动性的单相整流负荷，其在行进途中将向电网大量地注入高次谐波，直接威胁电网的安全运行。本文针对向京广电铁河南境内牵引站供电的各系统变电站，利用计算仿真模拟计算，研究谐波对各变电站并联电容器设备运行的影响、并提出了改进和治理措施。     

从智能微网到智能配电网的分析

介绍了智能电网研究的目标,分析了智能微网向智能电网发展的可行性。     

电网企业经营风险及对策

市场环境下任何企业的生存与发展都存在着一定的风险，电网企业也不例外。近年来，随着电力体制改革的不断深入，电网企业逐步由过去的垄断型向竞争型转变，市场环境下的电网企业经营风险防范成为其经营管理及改革研究的一大课题。     

前智能电网时代的电网规划研究

前智能电网发展阶段要实现向智能电网的良好过渡,首先要考虑电网规划的问题。结合当前国际对电网发展的研究,分析我国电网规划的问题,研究了前智能电网时代电网规划的目标、需要考虑的主要因素以及约束条件等与规划相关的问题,提出了基本思路和有关建议。     

"十五"西电东送广东电网受电能力研究

为配合国家西部大开发战略，“十五”期末贵州、云南、天生桥及三峡等将向广东送电10000MW，南方4省将形成世界上最大的交直流互联电网，有关的系统研究表明，在一定的电网结构上，影响广东电网受电能力的关键因素是受端电网的无功电压支撑及交直流系统的相互配合问题。     

浅议集约型发展电网

论述了电网的发展由粗放型向集约型转变的必要性，重点阐明了集约型发展电网的十大效益和措施。     

步进电机的单片机控制设计分析

步进电机是一种将脉冲信号转换为相应角位移的执行元件,在工业控制领域应用广泛。本文介绍了步进电机的控制原理,详细论述了采用单片机的控制方法,并以35BY48L02步进电机为例,分析设计了单片机的硬件接口电路及步进电机的软件控制方法。该设计具有通用性,对于不同步进电机,可以通过修改相应的电路及相关程序实现,提高了系统控制的灵活性。     

一种新型软开关BUCK变换器

针对影视照明用大功率电子镇流器的特殊要求，提出了一种新型软开关BUCK变换器。新型电路具有大功率、低损耗等优点。给出了控制策略，阐述了新电路的工作原理。给出了主电路的参数设计方法。对新电路进行了仿真研究。理论和仿真结果表明，新电路中的所有功率开关全是软开关，大大降低了开关损耗。制作了一台输出功率为6kW的实验样机。实验结果与理论和仿真结果吻合。实验结果表明，用新电路代替原来的硬开关电路，整机效率提高了8%，新系统的效率为93%。     

SoC芯片内嵌模数转换器的验证测试

如何对系统芯片(SoC)中内嵌的模数转换器进行验证测试,是集成电路测试技术研究的重点和难点之一.对一款应用于有线数字电视传输中信道解调解码芯片中内嵌模数转换器的测试方法进行了研究,在分析芯片功能和引脚的基础上,列出了具体的测试夹具开发方案和电路引线图,针对内嵌式ADC的特点,给出了测试向量中测试矢量的时序关系,根据时序...     

Performance analysis of LCL-T resonant converter with fuzzy/PID controller using state space analysis

A closed loop series parallel resonant converter with LCL-T configuration has been simulated and presented in this paper. The fuzzy/PID controller has been used for closed loop operation and the performance of proposed converter has been estimated with the closed loop and the open loop condition. The mathematical model using state space approach has been developed and simulated using MATLAB. The performance of the converter has been found to be better when the fuzzy controller has been considered. The Harmonic Spectrum and steady state error for various load condition have been obtained to validate the role of controllers. The proposed approach is expected to provide better voltage regulation for dynamic load conditions.     

Analysis and design of rectangular microstrip antenna on two-layer substrate materials at terahertz frequency

In this paper, an effective permittivity of the two-layer dielectric substrate material has been analyzed to enhance the electrical performance of the rectangular microstrip patch antenna at terahertz frequency. The frequency dependent effective dielectric permittivity of the substrate materials has been evaluated and result has been compared with finite integral technique based CST Microwave Studio a commercially available simulator. The input impedance characteristic with electrical performance of the rectangular microstrip patch antenna on two-layer substrate materials has also been analyzed at 600 GHz. Manipulation in the input impedance characteristic of the antenna has led to a slow wave structure. This slow wave structure has been examined at 542 GHz, and improvement in the performance has been observed without increasing the overall dimension of the proposed antenna.     

Synthesis of optimal controller for synchronous power system

During the last decade research work has been in progress in the area of system optimisation by control system engineers. Power system engineers have been endeavouring to apply the optimisation technique to obtain an optimal controller to improve the transient response of a synchronous power system.In this paper an attempt has been made to select the best control quantities with a view to extending stability boundaries and improving transient response. The transient response corresponding to different combinations of control quantities was considered when selecting the most effective control law.The optimal control law obtained on the basis of the quadratic index of performance for one particular condition has been tested for operating conditions over a wide range, and the possibility of adopting the same controller for all other operating conditions has been investigated. The influence of local load on the optimal control law and transient response has also been examined, and that of governor and turbine dynamics on the transient response has been assessed.     

电力产业体制变革进程分析及展望

运用交易费用、纵向一体化、自然垄断等相关理论,对电力产业体制变革的进程分析后认为,电力产业在体制上经历了从分散的小规模的私有化到大规模国有化、集中化,再到相对分散化的演变过程,在竞争模式上经历了从早期市场化自由竞争到纵向一体化垄断、纵向产业结构拆分,实现更高层次市场竞争的过程。对比分析了电力产业在不同阶段的产业模式及其特征,并对我国电力产业深化改革的走向进行了判断和展望。     

基于LabVIEW通信虚拟实验系统

在Windows XP系统下,使用LabVIEW开发了通信虚拟实验系统.该系统使用虚拟仪器技术,解决了传统通信实验硬件电路构建复杂的缺陷,具有界面友好,维护简单等优点.文中详细介绍了系统的开发背景,软件结构和特点,实验证明该系统具有很好的教学实验效果.     

Determination of Energy Intensity of Autonomous Power Supplies Taking into Account Interruptible Service of Power Mains

A methodological approach for determining the energy intensity of autonomous power supplies in the presence of interruptible power service due to the overrange of supply quality indices has been considered. The modes of operation of the power supply system have been represented in the form of a Markov chain with discrete states and continuous time. The exponential rule of a working time distribution of the power feeds has been adopted. A marked graph of states of the power supply system that consists of the state electric mains, uninterruptible power supply equipment, and a standby diesel power station has been constructed. The matrix of transition probabilities has been created, and the analytical expressions have been obtained to determine ultimate probabilities. Since the ultimate probabilities are the mean relative residence time of the system in the given state, the analytical expression has been deducted to determine operating time of the storage battery used in the equipment of uninterruptible power supply. The operating time of other standby power supplies can be similarly calculated.     

基于LabVIEW的测试信号预处理方法研究

本文主要讨论了当前测试信号预处理中消除趋势项常用的平均斜率法,详细介绍了该方法的原理及不足,在此基础上提出了用最小二乘法消除趋势项的方法,并在LabVIEW平台上编程实现。最后通过对磁性测量信号的分析验证了算法的可行性。