转炉氧枪控制系统中编码器的应用与关联

氧枪是转炉炼钢的关键设备之一,它的控制系统性能关系到冶炼钢水的质量与效率。要想保证氧枪系统的安全稳定运行就必须有一套完善的控制体系。简介了转炉氧枪的控制系统以及控制系统中的重要电器设备,简述了编码器的分类及原理,详细说明了速度编码器和高度编码器在氧枪升降控制中起到的作用,并且初步构思了两种编码器所采集的数据共享的方法。     

串联谐振逆变器的内环模糊控制仿真研究

利用模糊控制的优点来对谐振逆变器电路进行控制仿真研究。结果表明,与同样条件下的PID设计方法相比,模糊控制逆变器系统的输出在幅值和相位的稳态精度都得到了提高．系统的动态性能有了明显的改善。     

南昌发电厂125MW机组送风机变频节能改造

介绍了完美无谐波变频器的工作原理及其在送风机上的应用,对变频器安装、调试等阶段中出现的问题进行了讨论并提出建议。实践证明,电机变频调速是有效的节电措施。     

变频器异常检测方法研究与仿真

提出了一种异常参数映射估计的变频器异常动态参数检测算法。提取变频器异常动态参数,建立动态参数与变频器部件之间的映射关系,对变频器动态参数进行非线性变换,计算变频器动态参数异常区间排除干扰。实验证明,这种检测方式能够提高变频器异常检测的准确率,能够准确检测故障部件。     

A 6-switch single-phase 5-level current-source inverter

INTRODUCTION Up to now, multilevel voltage-source inverters(VSIs) (Fang, 2001) have been paid more attentionthan multilevel current-source inverters (CSIs) in thehigh-power fields. One of the most important reasonsis that inductors, as energy storage elements, have thedisadvantages of higher conducting losses and lowerenergy storage efficiency than capacitors. However,with the development of superconducting magneticenergy storage (SMES) technology (Luongo, 1996),superconducting induc…     

最少化直流电压源的新型多重化拓扑结构的研究

Multilevel inverter has become increasingly popular in recent years due to advantages of high power quality waveforms ,low switching losses,and high-voltage capability. A novel multilevel inverter with minimum number of separated DC sources is presented in this paper.Three-phase output voltages of this inverter can easily be balanced they are synthesized by using the same DC sources.A harmonic reduction method eliminating both the 5th and 7th harmonics is proposed.Finally,comparison results and spectral analysis are presented.     

基于Matlab／Simulink的离网型太阳能光伏发电系统仿真研究

提出一种离网型太阳能光伏发电系统的设计方案,阐述了其工作原理,基于MATLAB／SIMULINK仿真软件,构建了离网型光伏发电系统仿真模型并进行了仿真分析。仿真结果表明所提出的离网型太阳能光伏逆变器的设计方案是可行的。     

A new three-phase 5-level current-source inverter

INTRODUCTION Multilevel converters can offer substantial benefits for higher power applications compared to two level inverters, including reduced harmonics, and increased power ratings because of reduced switching device voltage and current stresses. However, until recently, multilevel voltage source inverters (Peng, 2001) have been the dominant multilevel topology, despite the fact that current-source inverters (CSIs) have many advantages for higher power applications. These include mo…     

Applications of cascade multilevel inverters

Cascade multilevel inverters have been developed for electric utility applications. A cascade M-level inverter consists of (M-1)/2 H-bridges in which each bridge's dc voltage is supported by its own dc capacitor. The new inverter can: (1) generate almost sinusoidal waveform voltage while only switching one time per fundamental cycle; (2) dispense with multi-pulse inverters' transformers used in conventional utility interfaces and static var compensators; (3) enables direct parallel or series transformer-less connection to medium- and high-voltage power systems. In short, the cascade inverter is much more efficient and suitable for utility applications than traditional multi-pulse and pulse width modulation (PWM) inverters. The authors have experimentally demonstrated the superiority of the new inverter for power supply, (hybrid) electric vehicle (EV) motor drive, reactive power (var) and harmonic compensation. This paper summarizes the features, feasibility, and control schemes of the cascade inverter for utility applications including utility interface of renewable energy, voltage regulation, var compensation, and harmonic filtering in power systems. Analytical, simulated, and experimental results demonstrated the superiority of the new inverters.     

一种基于DC/DC变换器拓扑的逆变器研究

本文针对传统的逆变器存在功率管直通和难以实现软开关的缺点 ,提出了一种新颖的基于DC/DC变换器拓扑的逆变器 .该逆变器由一个组合的Buck/Boost直直变换器和一个桥式电路构成 ,前级变换器输出可变的直流电压 ,后级电路将直流电压转换为交流输出 .该逆变器可以实现逆变桥功率管的软开关 .由于采用了能量反馈和单周期控制技术 ,变换器具有良好的动态性能 .本文对该变换器的电路拓扑和控制原理进行了详细分析 .电路仿真及样机实验结果表明该逆变器具有良好的性能