采用CMOS数字集成电路的可编程时间顺序控制器

介绍了一种采用CMOS数字集成电路制成的时间顺序控制器的工作原理,讨论了其性能特点、适用范围和功能扩展,给出了具体电路设计.     

基于CMOS缓冲器的路灯线路光时控制器

根据CMOS缓冲器的特点,对采用CMOS缓冲器组成路灯线路控制器进行了研究。讨论了其电路组成,参数设计,并通过电路仿真证明其可行性。该控制器结构简单,成本低,控制可靠,特别适合于控制住宅小区、工厂、机关、学校等小范围的路灯线路。     

高压电动机故障的原因及防范措施

0 引言 火力发电厂厂用高压电动机是锅炉和发电机组配套的动力设备,它们在保证发电机组及锅炉安全稳定运行中起着极其重要的作用.     

A High-Voltage Isolator for Conductive Liquids

In certain manufacturing operations, and particularly in electrostatic spray-coating, portions of a conductive liquid line may be exposed to a high potential. To localize the high potential, a new isolation system has been developed that allows the continuity of the conductive liquid to be broken and insulated by a gas medium. Experiments show that potential differences up to 100 kV may be successfully isolated over a distance of 10 cm.     

Miniaturized High-Voltage Power Supplies for Electrostatic Devices

A requirement for new electrostatic devices of crude but very low-cost extra high voltage (EHV) power supplies has been met by modifying existing circuits in a relatively minor way. Two such systems are described. For the first, the relatively expensive components normally specified have merely been ``designed out' but at some sacrifice to electrical efficiency. In the second case, component additions to a volume-produced circuit intended for other purposes have enabled a very low-cost system to be realized. Output power is very limited, however, for this latter system.     

冶金行业高压断路器的选择

0引言 冶金行业电力系统由于其环境特殊,运行情况较为复杂,系统电压不太稳定,以及谐波的存在,系统过压现象较为严重,特别是开断电炉变压器,单炉断路器动作次数20次/炉以上,每昼夜动作200次以上,平均日作业率9 5%以上,因此,需要选择一种既安全,又可靠的断路器.     

高压异步电动机的微机式过热保护

电动机的绕组温升是按指数规律变化的过程,如何模拟这一过程是实现电动机过热保护的关键。现分析电动机的温升过程,按其热平衡方程建立以热等效电流为基础的过热保护数学模型,并详细阐述该模型的计算机算法实现。     

Power Supplies for Electronic High-Voltage Measuring-Current Transformers

A power supply for electronic high-voltage measuring-current transformers with extraction of energy from the measured current that flows through a high-voltage line has been considered. A magnetic core of the supply transformer from the windings of which the necessary power is extracted is mounted on the line for this purpose. When the line current changes over a wide range, the supply transformer should have a quickly saturated magnetic core. It has been shown that, to reduce the losses and decrease the loading of the elements of a power-supply circuit in a wide current range, a ballast load should be introduced in the circuit of a secondary winding. Three variants of the ballast load have been compared: resistive, capacitive, and in the form of a transistor-current limiter. The results of simulations in the VisSim software have been considered for all three variants, as well as for the case of absence of a ballast load in the power-supply circuit. The simulations were carried out for the lowest and highest measured currents, as well as for the line short-circuit mode. The results of simulations have shown the advantages of a power supply based on a saturated transformer with a transistor-current limiter. A variant of a circuit of a transistor-current limiter has been suggested.     

新型高压发电机及其特点

概述世界目前高压发电机的开发与应用现状及其性能参数。介绍日本北海道三笠市桂泽发电厂的66kV高压发电机的技术特点，涉及本体结构，线圈导线结构与规格、冷却、励磁、主接线及保护等各个方面。说明采用高压发电机可具有降低损耗、提高效率、节省变压器及相应开关的投资、提高可靠性及节省占地面积等多方面的优越性。     

高压电机智能检测系统的研制

介绍了一套基于低压变频机组的高压电机检测系统,通过采用工控机为上位机、PLC为下位机,实现高压电机型式试验自动控制,对检测数据进行专家系统程序化故障判别和智能诊断,自动生成检测报告.     

一种驱动螺旋钻机的专用高压变频器

针对开采薄煤层、延长矿井的使用寿命、提高煤炭资源利用率,螺旋钻进式采煤机提供了良好、有效的选择。为螺旋钻机系统设计了防护等级为IP56的1600 kW/3.3 kV变频器。该变频器采用18脉波移相整流的移相变压器,实现电网侧无谐波干扰。拓扑结构上采用多电平功率单元串联技术,输出13电平,正弦度高,d u/d t小,不会损伤电缆和电机绝缘。变频器移相变压器和功率单元均采用水冷散热方式,实现高效、可靠的散热。变频器性能上满足螺旋钻进式采煤机的3倍起动转矩、急加速、急减速等特殊工况要求,并预留远程通信接口,方便用户进行信号控制与数据采集。     

矿用潜水电泵高压电机设计

通过实例介绍了矿用潜水电泵高压电机的外壳、轴、轴承、接线盒、电磁性能等方面的系统设计方法,指出电机和水泵联合设计的概念,列出了外壳、轴、轴承设计的理论计算公式和判断标准。     

High-Voltage Equipment Considerations for a New Tire Plant

The sizing of primary substations, distribution voltage selection, power-factor correction techniques, and unit substation sizes are discussed for general manufacturing facilities' power distribution. These areas are explored with respect to the specific requirements of a tire manufacturing plant.     

Low-Power High-Voltage Power Modulator for Motor Insulation Testing

Variable-speed pulsewidth-modulated (PWM) drives allow for precise speed control of induction motors, as well as a high power factor and fast response characteristics, compared with nonelectronic speed controllers. However, due to the high switching frequencies and the high $dV/dt$, there are increased dielectric stresses in the insulation system of the motor, leading to premature failure, in high power and medium- and high-voltage motors. Studying the degradation mechanism of these insulation systems on an actual motor is both extremely costly and impractical. In addition, to replicate the aging process, the same waveform that the motor is subjected to should be applied to the test samples. As a result, a low-power two-level high-voltage PWM inverter has been built to replicate the voltage waveforms for aging processes. This generator allows for testing the insulation systems considering a real PWM waveform in which both the fast pulses and the fundamental low frequency are included. The results show that the effects of PWM waveforms cannot be entirely replicated by a unipolar pulse generator.      

高压开关设备的智能化

机电一体化技术用在开关设备中,即把计算机加入机械系统,使之开关系统有了“大脑”,再加入“传感器”采集信息,用光纤传导信息,使开关系统有了“知觉”,大脑根据“知觉”做出判断与决定,使系统有了“智能”,现代二次技术使开关设备“智能化”。     

高压电动机的保护

阐述了高压电动机测温保护、过电压保护及差动保护的基本原理及元器件在高压电动机中的安装与应用的探讨.     

统一潮流控制器的非线性控制

通过独立控制线路的有功和无功功率,统一潮流控制器(UPFC)能够大大提高线路的传输能力。为实现这一目标,装置需要尽可能快的动态响应速度和稳定性。文中提出一种适用于UPFC装置的非线性控制策略,该控制器的理论分析基于同步旋转坐标系,充分考虑了UPFC模型的非线性特点,采用反馈精确线性化的方法进行分析。在此基础上设计得到的控制器较之传统的PI控制和解耦控制策略具有更好的稳定性和更快的动态响应。在EMTDC/PSCAD平台下的仿真结果验证了这种控制策略的优越性能。     

高压变频器中移相变压器的继电保护整定

阐述了高压变频器中移相变压器继电保护的特殊性,最后给出移相变压器继电保护整定的经验公式,同时,对特殊装置的继电保护整定提出一种分析思路.     

静电除尘器用智能高压直流电源的研制

介绍了一套替代传统电源的静电除尘器用智能高压直流电源。该电源以IGBT为主功率器件,SKHI22AH4为驱动电路,UC3875为PWM控制芯片;应用逆变技术,其计算机控制以单片机为主控芯片,由PI算法实现外特性控制;集传统电源的低压、高压和控制系统为一整体,电源输出可为纯直流和脉冲两种形式,外特性可为恒压、恒流和缓降三种形式,参数调节和工作状态可分别通过近控和远控调整。现场实验表明,该电源在输出电特性的可控性、重量、体积、使用效果、节约成本及操作安全等方面都较传统电源有明显优势。