特种电源（8）

本文例举了几种特种电源的工作原理和应用,这几种特种电源是电解用整流器、电镀电源、同步电机励磁电源、直流电动机调速电源、蓄电池充放电电源和直流弧焊机用电源。     

特种电源（6）

本文例举了几种特种电源的工作原理和应用,这几种特种电源是电解用整流器、电镀电源、同步电机励肱电源、直流电动机调速电源、蓄电池充放电电源和直流弧焊机用电源。     

特种电源（二）

本文例举了几种特种电源的工作原理和应用,这几种特种电源是电解用整流器、电镀电源、同步电机励磁电源、直流电动机调速电源、蓄电池充放电电源和直流弧焊机用电源。     

特种电源（11）

本文例举了几种特种电源的工作原理和应用,这几种特种电源是电解用整流器、电镀电源、同步电机励磁电源、直流电动机调速电源、蓄电池充放电电源和直流弧焊机用电源。     

特种电源（5）

本文例举了几种特种电源的工作原理和应用,这几种特种电源是电解用整流器、电镀电源、同步电机励磁电源、直流电动机调速电源、蓄电池充放电电源和直流孤焊机用电源。     

特种电源（9）

本文例举了几种特种电源的工作原理和应用,这几种特种电源是电解用整流器、电镀电源、同步电机励碰电源、直流电动机调速电源、蓄电池充放电电源和直流弧焊机用电源。     

特种电源（一）

本文例举了几种特种电源的工作原理和应用,这几种特种电源是电解用整流器、电镀电源、同步电机励磁电源、直流电动机调速电源、蓄电池充放电电源和直流弧焊机用电源。     

特种电源（12）

本文例举了几种特种电源的工作原理和应用,这几种特种电源是电解用整流器、电镀电源、同步电机励磁电源、直流电动机调速电源、蓄电池充放电电源和直流弧焊机用电源。     

特种电源（7）

本文例举了几种特种电源的工作原理和应用,这几种特种电源是电解用整流器、电镀电源、同步电机励磁电源、直流电动机调速电源、蓄电池充放电电源和直流弧焊机用电源。     

特种电源（3）

本文例举了几种特种电源的工作原理和应用,这几种特种电源是电解用整流器、电镀电源、同步电机励磁电源、直流电动机调速电源、蓄电池充放电电源和直流弧焊机用电源。     

特种电源(4)

本文例举了几种特种电源的工作原理和应用,这几种特种电源是电解用整流器、电镀电源、同步电机励磁电源、直流电动机调速电源、蓄电池充放电电源和直流弧焊机用电源。     

核电站控氮不锈钢Z2CN19-10焊接技术

控氮不锈钢因材质性能优良被广泛应用于核电站设备制造中,深入研究该钢种的焊接技术,对制造相关核电设备具有重要的意义.在分析了控氮不锈钢的焊接特点基础上,对其所采用的焊条电弧焊和埋弧焊工艺进行了试验和研究.通过选用合理的焊接材料、坡口型式和焊接工艺参数,可获得良好的焊缝质量,也使焊接接头具有良好的综合力学性能和抗晶间腐蚀能...     

Control freaks [induction furnace logic controller]

The induction furnace has been used in a massive range of applications from heating, melting and welding to shrink-fitting, forming, soldering and even plasma physics. Furnaces operate at frequencies between 10 Hz to 60 MHz, and as a result, different power supplies - operating at different frequencies - have also been developed. Induction steel heating furnaces (ISHF) have several advantages in practical applications. However, when a material is heated within an ISHF, its resistivity and magnetic permeability fluctuate, which proves detrimental to the control of power within the furnace. One way to improve power control within an ISHF is to use a programmable logic controller (PLC). Indeed, modern PLCs are modular, affordable, have large memory capacities, and also have special functions such as pulse wave modulation (PWM) and data communication. Using a PLC not only eases position, temperature and pressure control within the ISHF, but also provides overvoltage and overcurrent protection. A new PLC control system design allows heating to take place at constant power while maintaining a steady resonance frequency. The article introduces the system.     

开关电源中印刷电路板寄生参数对传导电磁干扰影响的研究

研究了开关电源中印刷电路板寄生参数及功率器件瞬态特性产生的传导电磁干扰现象。针对半桥型DC／DC变换器电路拓扑，使用Cadence软件中的Specctra Quest工具提取了印刷电路板上主要印制线的寄生参数，通过噪声等效电路模型的仿真计算，表明高频情况下印刷电路板寄生参数对传导电磁干扰有较大的影响。最后，对两台原理样机(仅印刷电路板布线不同)的工作波形进行了实验测试，实验结果表明功率器件开通和关断瞬间形成的电压和电流突变而造成的高频振荡现象与电路杂散参数有关。最后，对两台原理样机(仅印刷电路板布线不同)的工作波形进行了实验测试，实验结果表明功率器件开通和关断瞬间形成的电压和电流突变而造成的高频振荡现象与电路杂散参数有关，说明在不改变原理电路的条件下，通过合理设计印刷电路板布线可以有效提高开关电源的EMC性能。     

特种电源（10）

本文例举了几种特种电源的工作原理和应用,这几种特种电源是电解用整流器、电镀电源、同步电机励磁电源、直流电动机调速电源、蓄电池充放电电源和直流弧焊机用电源。     

山西电网常规电源“两个细则”管理实践与发展展望

分析了山西电网常规电源“两个细则”实施3年多来的情况,总结了“两个细则”实施取得的主要成效。结合山西电网电源结构特点和电力市场深化改革的方向,深入分析了常规电源“两个细则”相关规则在实施和管理中存在的问题,变提出了相关政策建议和发展方向。     

Investigating Pulsed Discharge Polarity Employing Solid-state Pulsed Power Electronics

The power electronics technique has become a key technology in solid-state pulsed power supplies. Since pulsed power applications have been matured and found their way into many industrial applications, moving toward energy efficiency is gaining much more interest. Therefore, finding an optimum operation condition plays an important role in maintaining the desired performance. Investigating the system parameters contributed to the generated pulses is an effective way in improving the system performance further ahead. One of these parameters is discharge polarity, which has received less attention. In this article, the effects of applied voltage polarity on plasma discharge have been investigated in different mediums at atmospheric pressure. The experiments have been conducted based on a high-voltage DC power supply and a high-voltage pulse generator for point-to-point and point-to-plane geometries. Furthermore, the influence of electric field distribution is analyzed using finite-element simulations for the employed geometries and mediums. The experimental and simulation results have verified the important role of the applied voltage polarity, employed geometry, and medium of the system on plasma generation.     

新电磁兼容标准条件下的功率因数校正电路的设计分析

电磁兼容标准是强制性的,因此满足特定的电磁兼容标准是功率因数校正技术研究的重要内容.低成本小功率的开关电源设计以满足电磁兼容标准为目标,电流谐波限制标准的要求不同对于电路的设计有很大的影响.由于IEC1000-3-2电磁兼容标准的变化,许多过去标准中划分为D类装置设备在新版本标准中划分为A类,通过分析计算,按照新标准重新计算的开关电源磁元件尺寸可大幅度地减小,进一步降低成本和提高性能价格比.本文以有源单级功率因数校正电路和无源LC功率因数校正电路为例,对新电磁兼容标准条件下功率因数校正电路进行设计分析.实验结果与理论预期十分接近.     

Active and reactive power sharing and frequency restoration in a distributed power system consisting of two UPS units

A distributed power system consisting of two uninterrupted power supplies (UPS) is investigated in this paper. Parallel operation of the two sources increases the established power rating of the system. One of the sources can supply the system even when the other system is disconnected due to some faults, and this is an important feature. The control algorithm makes sure that the total load is shared between the supplies in accordance with their rated power levels, and the frequency of the supplies are restored to the rated values after the transitions. As the UPSs operate at an optimum power level, losses and faults due to overloading are prevented. The units safely operate without any means of communication between each other. The focus of the work is on the inverter stages of the UPSs. Simulations performed in Matlab Simulink environment have been verified with experimental work via DS1103 controller card.     

IGBT模块封装工艺的研究

随着能源技术的发展,电力电子器件日益受到人们的关注,绝缘栅双极型晶体管(insulated-gate bipolar transistor,IGBT)作为功率半导体的主流器件在能源领域得到了广泛应用。目前IGBT模块已经在电动汽车、高速铁路以及电力设备等领域发挥着不可替代的作用。IGBT模块的封装作为一个新兴产业越来越受到人们的关注。以IGBT模块的封装工艺为研究对象,确定模块封装两次焊接的顺序,选择两次焊接的焊料,确定焊接温度及回流温度曲线。最终焊接效果良好,有效地提高了IGBT模块封装的工艺水平。