Electric power system state estimation

This paper discusses the state of the art in electric power system state estimation. Within energy management systems, state estimation is a key function for building a network real-time model. A real-time model is a quasi-static mathematical representation of the current conditions in an interconnected power network. This model is extracted at intervals from snapshots of real-time measurements (both analog and status). The new modeling needs associated with the introduction of new control devices and the changes induced by emerging energy markets are making state estimation and its related functions more important than ever     

基于FPGA的电动助力转向系统

采用Verilog硬件描述语言自顶向下的设计方法,通过FPGA实现了车辆电动助力转向系统的设计.论述了计数模块、查询模块与电机控制模块的工作原理,通过对车速、转向盘扭矩和转角查表得到对应的助力控制、回正控制和阻尼控制模式与控制值,实现了车辆低速时的转向轻便性和高速时对驾驶员路感的保证.利用Cyclone EP2C8控制板在实验台架上的实验表明,系统能够实现所设计的功能,并具有较高的响应速度.     

基于分布式实时数据库的电能量计费系统

为了解决电能量计费系统中要保存大量历史数据的数据库技术问题,采用分布式实时数据库系统技术.具体介绍了分布式实时数据库系统的基本结构,以及CPU调度算法、I/O调度算法、事务提交协议、并发控制协议。从电力企业需求出发,在电能量计费系统TMR中应用分布式实时数据库,实现了跨操作系统的电能量计费,降低了网络流量,提高了各节点的数据查询速度,从而提高系统的响应速度,为进行实时的线损计算提供了基础。     

Electric field mapping system using an optical-fiber-basedelectrooptic probe

A microwave electric-field mapping system based on electrooptic sampling has been developed using micromachined GaAs crystals mounted on gradient index lenses and single-mode optical fibers. The probes are able to detect three orthogonal polarizations of electric fields and, due to the flexibility and size of the optical fiber, can be positioned not only from the extreme near-field to the far-field regions of microwave and millimeter-wave structures, but also inside of enclosures such as waveguides and packages     

电动地坦克运动控制系统设计

基于单片机以及CAN总线,设计一种能实现360°自由转向的永磁无刷直流电机驱动的电动地坦克运输装置。利用无线通讯技术所提供的控制信号,通过选择合适的控制算法,实现对两路直流电机运动的协调控制。运动控制系统具有快速、平稳和准确的特性。     

基于Windows CE的线路巡检系统

首先讨论了现有线路巡检模式的不足，然后提出了利用windows CE来构建线路巡检系统。分析了该系统的硬件平台之后，提出了线路巡检系统的体系结构，阐述了该系统应具有的软件功能。在实际应用中表明，该系统在线路巡检中有较强的推广价值。     

基于人工智能的电力114查号系统建设

随着电力系统程控交换设备逐步退网和IP多媒体子系统(IP Multimedia Subsystem,IMS)网络的全面部署,电力行政交换系统将不再提供传统的E1数字或模拟中继,导致现有查号系统无法继续工作.同时随着人工智能技术的逐步成熟,智能化取代人工的趋势不可避免.为了适应IMS网络全网部署后全新的网络架构及人工智能...     

河北南网卫星应急通信系统建设方案研究

通过对卫星应急通信系统技术体制的分析,提出了河北南网卫星应急通信系统建设方案。主要包括:地面卫星应急通信中心站、卫星便携站和卫星应急通信车系统的建设。     

分布式电能计量互感器检测仿真平台设计

电能计量互感器直接与供电企业和用户利益相关,因此电能计量互感器定检至关重要,为有效改善检定人员素质,本文设计了一种分布式仿真检定平台,其由控制台、电能计量互感器检测仿真平台等组成;本文较为详细阐述电能计量互感器检测仿真平台中关键设备的设计与实现.     

支持智能问答的电能计量互感器检测仿真培训系统

电能计量互感器是决定电力企业经济效益和用户成本的关键设备,因此需定检,为了提高检定人员素质,本文在已有的检测仿真培训系统的基础上设计了一种可智能问答软件模块,首选介绍了问题模块关键字匹配算法,然后给出了智能问题模块的实现方案,最后通过实际统计数据证明了该模块的实用性.     

Electric regeneration

Electricity is often featured in the media for its role in causing pollution: acid rain and the greenhouse effect are two side effects of power generation. However, electricity plays a vital role in the treatment of many liquid and gaseous effluents and in new techniques that are being developed to recycle wastes and recover valuable resources from them. The author concludes that electricity can solve more problems than it creates     

Electric vehicles

The renewed interest in electric vehicles (EVs) in the wake of the California Air Resources Board mandate that 2% of the vehicles lighter than 3750 lb (1700 kg) sold by each manufacturer in that state in 1998 be zero-emission vehicles is examined. The reasons why replacing an internal combustion vehicle (ICV) with an electrically powered equivalent greatly reduces air pollution, not only where the EV is driven, but over the rest of the map as well are discussed. Three drawbacks that have kept EVs from taking over, despite the fact that they are quieter and more reliable as well as less polluting than their internal combustion counterparts, are discussed. They offer limited range on a simple charge, long recharge time, and higher cost than ICVs. The importance of an appropriate infrastructure is stressed     

DSP-Based Sensorless Electric Motor Fault Diagnosis Tools for Electric and Hybrid Electric Vehicle Powertrain Applications

The integrity of electric motors in work and passenger vehicles can best be maintained by frequently monitoring its condition. In this paper, a signal processing-based motor fault diagnosis scheme is presented in detail. The practicability and reliability of the proposed algorithm are tested on rotor asymmetry detection at zero speed, i.e., at startup and idle modes in the case of a vehicle. Regular rotor asymmetry tests are done when the motor is running at a certain speed under load with stationary current signal assumption. It is quite challenging to obtain these regular test conditions for long-enough periods of time during daily vehicle operations. In addition, automobile vibrations cause nonuniform air-gap motor operation, which directly affects the inductances of electric motors and results in a noisy current spectrum. Therefore, it is challenging to apply conventional rotor fault-detection methods while examining the condition of electric motors as part of the hybrid electric vehicle (HEV) powertrain. The proposed method overcomes the aforementioned problems by simply testing the rotor asymmetry at zero speed. This test can be achieved at startup or repeated during idle modes where the speed of the vehicle is zero. The proposed method can be implemented at no cost using the readily available electric motor inverter sensors and microprocessing unit. Induction motor fault signatures are experimentally tested online by employing the drive-embedded master processor (TMS320F2812 DSP) to prove the effectiveness of the proposed method.      

浅谈电动自行车电池

文中阐述了电池的充电技术及其与电动车各部件的关系、电池失效的原因和电池的更换,便于加深对电动自行车电池的了解和电池的正确使用。     

智能电动车模拟设计

本设计采用单片机(ATC89S52)作为电动车跷跷板的控制核心,智能控制电动车在跷跷板上固定水平状态和跷跷板状态时,行驶完成从起始端到尾端,停留5 s后返回到起始端.并分别显示前进和倒退所用时间等功能.引导方式采用反射式红外传感器感知,采用与白色板面颜色有较大差别的黑色引导线,平衡判断采用自制摆陀与光耦合器构成的角度传感器;驱动电机采用直流减速电机;电机控制方式为调压调速的PWM控制;计时与显示采用单片机内置定时器处理后由液晶显示器(LCD)输出.测试数据表明文中设计的智能电动车可以完成基本功能,水平状态及跷跷板上运行时间均较短,效果良好.     

基于ANN和残差修正的电力系统短期负荷预测

提出了一种人工神经网络与灰色理论模型相结合的综合预测方法。在神经网络结构设计中分别选取带有横向和纵向特征的负荷作为输入，并充分考虑气候敏感因素及特殊负荷日的影响。在分析预测差值的基础上，将灰色理论残差校正模型运用到预测结果的修正当中去。算例表明所提出的方法提高了预测精度。     

Power Electronics and Motor Drives in Electric, Hybrid Electric, and Plug-In Hybrid Electric Vehicles

With the requirements for reducing emissions and improving fuel economy, automotive companies are developing electric, hybrid electric, and plug-in hybrid electric vehicles. Power electronics is an enabling technology for the development of these environmentally friendlier vehicles and implementing the advanced electrical architectures to meet the demands for increased electric loads. In this paper, a brief review of the current trends and future vehicle strategies and the function of power electronic subsystems are described. The requirements of power electronic components and electric motor drives for the successful development of these vehicles are also presented.