浅析电弧炉炼钢中的谐波及其抑制

综合治理谐波并同时考虑电网的无功功率补偿问题,是电力企业当前面临的一大课题。但是要消除谐波污染,除了电力系统中大力研究高效的滤波措施外,还必须在设计、制造和使用非线性负载(如电弧炉)时,采取有力的措施抑制谐波,减小谐波侵入电网,从而真正减少由于谐波污染带来的巨大经济损失。文章针对电弧炉炼钢中谐波的产生及其危害,归纳总结了目前电力系统中进行谐波检测及其抑制的常用方法,提出了双向检测双重滤波的思想,这对改善电能质量有一定的促进作用。     

电弧炉的混合仿真模型

为了表征电弧炉在运行过程中能量耗散的物理特性，实现供电系统与冶炼设备组成的多学科系统的混合仿真，宏模型采用了电弧炉电弧功率关系的非线性微分方程，及描写电弧炉时域响应中低频不确定信号的非线性微分方程组，将它们分别表示为含有线性时不变元件和多维、高阶、非线性受控源的电路模型，电弧电压信号与低频混沌信号进行调制后，最终得到的电弧炉输出电压将具有电压谐波和电压闪变等特性。该模型的参数均可在仿真时调整或在选定范围内进行连续仿真，满足了各类电弧炉在冶炼的不同阶段建模的实际需要。文中以电弧炉精炼期为例进行仿真的结果表明，使用本文所提出电弧炉电路宏模型能对电弧炉系统进行切合实际的时域分析，仿真结果能为预测电弧炉对电能质量的污染提供可靠的数据。     

电弧炉微机控制系统

使用一台ＩＢＭ—ＰＣ微机控制一台ＨＧＸ型８．５吨炼钢炉，实现生产自动控制，不仅提高产品质量，节约能源，同时也大大改善工作环境，减轻工人的劳动强度．     

有源电力滤波器谐波电流检测研究及仿真

介绍了一种基于改进型谐波检测方法.该改进型检测方法用积分、延时和增益环节代替传统ip、iq检测方式中的低通滤波器,检测延时可减少到1/6个电源周期,同时这种方法可以推广到单相、三相四线电路和三相不平衡负载的场合中.仿真结果验证了该控制方案的正确性.     

发电厂电气系统谐波抑制措施探究

随着我国国民经济的快速发展,干式变压器以其环保、节能、电气性能优越的特点,在输配电的各个领域都有广泛的应用.本文分析了电力系统中谐波的成因及危害,并从干式变压器自身和配备的电力电子设备两个方面概括性地介绍了抑制电力系统谐波的措施.最后得出了伴随着变压器和电力电子技术的进步,谐波问题一定会得到很好解决的结论.     

民用电网谐波电流检测方法及仿真研究

针对民用电网中存在的电压不稳、三相不平衡和中线电流大等问题,在传统的ip-iq法基础上,采用对称分量法和零序电流分离法研究电流中的零序分量问题,并结合PI调节器建立数学模型对其谐波、基波负序和零序电流进行了实时检测。结果表明,该方法可准确地检测出电网电流中含有的谐波、基波负序和零序电流,且检测精度高、实时性好。     

电动汽车充电站及谐波治理仿真研究

由于非线性元件的存在,电动汽车充电过程会产生大量谐波电流。利用SIMULINK软件搭建电动汽车充电站仿真模型,通过研究电网侧电压电流的特点,发现在电动汽车充电过程中产生的5次、7次等谐波电流含量比较大,容易超过限值;并且以15台充电机同时工作情况为例,通过添加5次、7次单调谐无源滤波器和一个高通滤波器对谐波电流进行治理,取得良好的效果。     

电力系统高次谐波的危害及抑制方法

针对电力系统由于大功率电子变流设备的工业电弧炉的广泛应用,电网电压畸变产生高次谐波的原因,对电力系统及电网用户电气设备造成的危害进行了分析,探讨了其抑制的方法。     

Modeling of electrode system for three-phase electric arc furnace

To simulate the process of electrode operation, a dynamic model describing the electrode system of three-phase electric arc furnace was developed. This new model can be divided into three submodels in terms of the practical situation. They are the power supply system model the electric arc model and the hydraulic actuator system model. According to the basic circuit theory, the power supply system model where the high voltage transmission circuit and mutual inductances were considered, was set up. The electric arc model, which was novel for the electrode control, served as the electrical load and was connected to the power supply system model. The hydraulic actuator system model consists of the proportional valve part that is modeled to capture the dead-zone nonlinear characteristics and the hydraulic cylinder part where the impact of the load force is taken into account. By comparing simulation data and actual data, the results show that the electrode system model is proved to be accurate.     

Arc deflection model and arc direction control for DC arc furnace

Based on the analysis of three-dimensional power conductor for DC arc furnace, the electric arc deflection model was set up and the control system of the arc direction was configured. According to the bus bar distribution at the bottom electrodes cooled by water, the arc direction control principle and its configuration were described, The simulation results show that the control system can restrain the electric arc deflection and control the arc direction.     

大型电弧炉计算机控制系统

介绍了大型电弧炉计算机控制系统的结构，主要功能及工作原理，并就系统软件ＡＭＸ及控制算法进行了讨论。     

交流电弧炉闪变及其影响因素分析

电弧炉在正常生产时会对电网产生以电压波动与闪变为主要特征的不利影响.根据弧长变化对电弧伏安特性造成的实际影响,提出以受控电压源的形式接入电力系统的电弧炉动态模型,可用来实现电弧炉电能质量的研究;并采用IEC闪变仪框图建立基于MATLAB的闪变测量模块,测量公共供电点的短时闪变值,分析电弧炉闪变的影响因素。分析结果表明,弧柱温度的波动区间越大,将产生更多的电压闪变.     

Mathematical Model on heat transfer of water—cooling steel—stick bottom electrode of DC electric arc furnace

For predicting and controlling the melted depth of bottom electrode during the process of steelmaking,the water-cooling steel stick electrode is taken as an example.to analyze the process of heat transfer,then 3D mathematical model by control capacity method is built.At the same time,the measurement on the melted depth of bottom electrode is conducted which verified the correctness of the built mathematical model.On the base of verification,all kinds of key parameters are calculated through the application and a series of results are simulated.Finally,the optimum parameters are found and the service life of bottom electrode is prolonged.     

Zinc leaching from electric arc furnace dust in alkaline medium

Physical and chemical properties of electric arc furnace (EAF) dust from Tianjin seamless Pipe Company were measured and analyzed. The zinc leaching tests in alkaline medium were carried out under variation of leaching agent concentration, leaching temperature, leaching cumulative time and solid-to-liquid ratio. The thermodynamics and kinetics of the zinc leaching process were also analyzed. The results show that the EAF dust contains 10% (mass fraction) zinc and the median particle size is 0.69 μm. The zinc recovery of 73.4% is obtained under the condition of 90 °C, 6 mol/L NaOH, and 60 min leaching time. With the increase of concentration of NaOH and the cumulative time, zinc leaching will be significantly increased. The kinetics study demonstrates that the leaching reaction is chemically controlled and the reaction activation energy is 15.73 kJ/mol.     

微波碳热还原不锈钢厂电弧炉粉尘的热力学及实验研究

采用微波加热方法进行碳热还原不锈钢厂电弧炉粉尘,并计算粉尘中金属氧化物的理论开始还原温度。结果表明,微波碳热还原不锈钢厂电弧炉粉尘在热力学上可行。实际测量的粉尘中金属开始还原温度比理论计算值低。微波加热物料过程中形成的热点和电弧可能导致局部高温,有利于碳热还原反应的进行。在900℃下,有部分粉尘被还原,随着温度的升高,粉尘的还原程度增大。还原出来的金属相主要以Fe-Cr-Ni合金的形式存在,且成分分布不均匀,残余相主要以FeCr2O4、Fe3O4、CaSiO3、（Mg,Al）SiO3和CaMgSiO4形式存在。     

汇东炼钢厂中频炉谐波分析与抑制

针对汇东炼钢厂中频电炉的谐波污染问题,对厂内电源侧以及变电站进行了电能质量测试,通过对测试数据的分析,得出11、13、17次谐波是造成电能污染的主要原因,并提出了在用户侧治理中频炉谐波污染的有效措施,即采用串接4.5％电抗器的方法,构成LC滤波电路,滤除7次及11次谐波,通过治理前后测量数据的对比,验证了措施的有效性.     

电弧炉的间接自适应模糊鲁棒控制

针对三相电弧炉电极调节系统的电极控制问题,设计了自适应模糊鲁棒控制器,给出了模糊鲁棒控制系统的详细设计过程.该方法考虑了跟踪误差和逼近误差对参数自适应律的影响,并对模糊逼近误差和外扰采用H∞补偿控制.仿真结果表明:该控制算法具有较好的动态响应和稳态控制精度,对外界干扰及结构参数不确定性具有很强的鲁棒性.     

三相电弧炉电极调节控制系统的鲁棒自适应控制

讨论了基于反馈线性化的鲁棒控制方法在在非线性系统控制中的应用.应用基于微分几何的反馈线性化方法将单相电极调节系统等价为完全可控线性系统,考虑三相耦合及弧长扰动的影响,设计了鲁棒自适应控制器,进行了MATLAB仿真.结果表明,基于反馈线性化鲁棒控制方法,可以有效克服三相耦合和弧长扰动的影响,在电弧炉电极调节系统控制中有一定的潜力.