大电流直流叠加供电在铝电解槽上的节能应用

对不同容量电解槽进行叠加供电，在我国有色系统铝电解行业属首例，特别是大电流可控硅机组与二极管机组进行大电流叠加供电在国内尚属首创。该技术从理论上和实际工作中都是可行的，特别对我国铝电解行业设备的更新改造，提供了宝贵的经验，为老设备改造、节约资金、创造更大经济效益闯出了一条新路。     

直流电弧炉的供电与炉壁耐火材料消耗的关系

应用耐火材料消耗指数的概念，提出了直流电弧炉的供电制度与炉壁耐火材料消耗关系的定量表达式。小强度供电和低电压、大电流操作都有利于改善炉壁耐火材料寿命，但对生产效率，石墨电极消耗会产生不利影响。     

常柴股份有限公司率先解决试车车间功率因数偏低行业难题

近年来随着小柴行业的飞速发展，为扩大生产能力，许多企业将柴油机装配试车基地扩散出去成为独立生产基地，但随之而来的问题是基地用电功率因数常徘徊在０．６左右，远低于供电部门功率因数≥０．９的考核要求，既影响了电网的供电质量，又提高了电费单价，增加了企业生产成本。这样的情况出现是柴油机电测功校车台架工作时，电机转速达到２０００转／分以上时处于发电状态，并向电网逆送电，产生大量无功电流，负载高峰时甚至使基地主变压器发生过载，特别在夏天时不得不用强力手段强制冷却，给生产和设备安全带来严重隐患，由于基地校车…     

计算机控制铝电解节能综述

计算机控制铝电解节能综述中国有色金属工业长沙公司傅世叶铝工业是高耗能行业，每电解一吨铝耗电约（１．４～１．８）万ＫＷ·ｈ，因此；降低电解铝的电耗已经成为国内外铝生产企业和行业主管部门注视的焦点。我国铝工业通过引进和创新相结合，以节电增产为目标，近几年...     

平衡电弧功率的三相电流不对称供电方法

研究了一种平衡三相电弧功率的不对称电流供电法。计算结果表明，对于所研究的炉子，在额定的电弧功率水平下，采用电流不对称供电法与电流对称供电法相比，电弧功率不平衡度由１９．６％下降至０．３３％，电效率不降低。     

三相异步电动机软启动技术

在一般启动中，三相异步电动机产生强大电流，从而降低了供电电压质量，造成对负载设备冲击。在发达国家多年来成功地采用了软启动技术，本文介绍了它的工作原理及我国的应用情况。     

钛渣冶炼电炉大电流供电线路与负载电路分析

钛渣电炉大电流供电线路的设计对钛渣电炉的正常运行起着重要的作用,圆形电炉和矩形电炉的大电流供电线路结构有各自的工作特点和不同的供电方式,选择合适的钛渣电炉供电方式,对于钛渣电炉的生产效率、炉衬耐火材料寿命、功率损耗、功率因数及电炉的稳定运行非常重要;大型钛渣电炉功率调节系统应采用阻抗控制的原理。     

基于QROGI的永磁同步风力发电机定子电流谐波抑制方法

针对永磁同步风力发电机驱动系统中定子电流谐波的问题,提出一种基于准降阶广义积分器（QROGI）的电流谐波抑制方法。将QROGI控制器引入电机控制电流环,利用QROGI控制器在设定交流频率处的高增益以抑制谐波电流;针对旋转坐标系下谐波电流分量在交直轴上表征为交流量,通过在电流内环叠加QROGI控制器实现对谐波电流的控制;对叠加QROGI的电流环控制器进行详细理论分析,对电流环控制器参数进行设计,给出详细的分析过程及控制器参数定量计算方法。最后通过搭建半实物实验平台验证了所提方法能够对永磁同步风力发电机定子谐波电流进行有效抑制。     

特高压双回线路潜供电流补偿方案仿真研究

对特高压同塔双回线路中潜供电流的产生机理进行了研究,分析了补偿潜供电流的原理,并且比较分析了中性点小电抗法和快速接地开关（HSGS）法2种不同的补偿措施。以淮南-上海同塔双回特高压输电线路为例,采用实际线路的参数,在PSCAD／EMTDC仿真软件搭建数学模型。通过计算潜供电流、熄弧时间等主要技术指标,分别对中性点小电抗法在不同负载率、不同故障类型和不同故障点位置的潜供电流进行综合比较,分析了影响潜供电流的因素。最后通过仿真,分别计算了采用中性点小电抗法和快速接地开关（HSGS）法的潜供电流,得到中性点小电抗法比较适合我国特高压线路。     

电压跌落时带有Crowbar电路的双馈感应发电机的瞬态分析

为了研究双馈感应发电机对电网电压跌落的适应能力,以及其实现低电压穿越的功能,文章通过将由向量法求出的瞬态电流与由等效电路法求出的稳态电流进行叠加而得出的定子、转子故障电流的近似解析式,来分析在定子端三相对称电压跌落、转子侧变换器断开、投入Crowbar电路情况下的双馈感应发电机内部的电磁关系变化过程。此外,在理论分析的基础上,文中建立了2　MW双馈感应发电机的PSCAD模型,且在7.5 kW双馈风力发电测试平台上进行了实验验证。仿真和实验结果表明,这种通过瞬态电流和稳态电流进行叠加的方法而求得的双馈感应发电机故障电流的近似解析表达式可以准确地反映出双馈感应发电机磁链和电流的瞬态变化。     

Hydrogen generation by electrolysis under subcritical water condition and the effect of aluminium anode

The productions of catalytic active materials and the reactor designs increasing the kinetics of the system are very important because of efficient energy production for electrolysis systems. In this study, the effects of subcritical water's conditions on electrolysis were investigated. All experiments were carried out under the subcritical water conditions, high temperature and pressure resistant reactor was used and the three electrodes were integrated in to the reactor. The aluminium anode was used to prevent the formation of oxygen in the reactor during obtaining pure hydrogen gas. The effect of pure (Al), Al-6013 and Al-7075 aluminium anodes on the electrolysis of water were investigated and compared with Pt anode. For all electrodes, Pt was used as cathode and Ag/AgCl electrode was used as reference electrode. Electrochemical Impedance Spectroscopy (EIS) measurements, current potential measurements were managed at −2 V, electrolysis current at 2 V constant potential during 1800 s was being followed and gas volume produced was measured to determine the most efficient aluminium anode. Energy consumption and hydrogen gases efficiency were also calculated for 25 °C room temperature. After determining the most efficient aluminium anode, the experiments were repeated in the subcritical water environment. Nitrogen gas was used to purge the system. The temperature was 130 °C and the pressure was 20 Bar. As a result, the use of aluminium alloys as an anode under the subcritical water conditions reduced energy consumption from 1400 kJ mol⁻¹ to 300 kJ mol⁻¹. The current density was increased to 370 mA cm⁻² at 2 V. The efficiency increase from %15 to %70, and the amount of hydrogen gas produced was increase from 18 mL cm⁻² h⁻ to 300 mL cm⁻² h⁻. In addition, using the aluminium anode eliminated the gas separation processes by providing purer hydrogen gas production.     

Influence of hydrodynamic parameters on the critical current density at water electrolysis: Mass flux,channel inclination and inlet void fraction

Hydrogen production rate increases as current density increases in a water electrolysis. At a certain high current density, the cell potential abruptly increases due to the hydrogen film formed at the cathode, which is known as the critical current density (CCD). Hence, it is imperative to increase the CCD for effective hydrogen production. However, the investigations regarding hydrodynamic parameters, which affect the CCD have hardly been performed. This work investigated the influence of the hydrodynamic parameters such as mass flux, inclination of cathode channel and inlet void fraction on the CCD in water electrolysis. The increase in the mass flux increased the CCD regardless of the channel inclination and the inlet void fraction due to the enhanced hydrogen bubble elimination near the surface, which retards hydrogen film formation. The influence of the inlet void fraction showed different trend according to the channel inclination. Monotonically decreasing trend was measured in the vertical channel due to reduced flow rate near the surface as the void fraction increased. Meanwhile, a peak was measured in the inclined channels. The inlet voids at bubbly flow regime dispersed the hydrogen bubbles from the cathode, while those at the slug flow regime aided and enhanced the hydrogen film formation at the cathode. It is concluded that the inlet void fraction either enhances or impairs the CCD depending on the flow regime. The authors expect that this work would shed light on the roles of hydrodynamic parameters for efficient hydrogen production.     

预磁极化条件下PEM水电解制氢特性与效率研究

为提高质子交换膜（proton exchange membrane,PEM）水电解制氢速率、降低电解所需能耗,针对磁场预极化条件下蒸馏水的分子极性和应力特性进行研究,通过构建磁场环境下氢质子的能级跃迁微观物理模型与磁化矢量——极化氢质子浓度对应的宏观数学模型,对不同磁场强度下电解液的离子电导率、电流密度和制氢速率进行定性和定量分析,并利用自主搭建的可调节预磁极化PEM水电解制氢试验平台对所提出方法的有效性进行重复试验。试验结果表明,经过预磁极化处理的蒸馏水电导率提高了2~3倍,且随着磁场强度的增加,PEM电解电流密度不断增大,极间电圧不断减小,制氢速率明显提升。     

Investigation of suitable cathodes for the production of hydrogen gas by electrolysis

The anodic and cathodic behaviours of aluminium, iron, mercury steel (HgSt), chrome-nickel steel (CrNiSt) and platinum have been studied in a 2N NaCl electrolyte (pH = 5) by means of electrolysis. The potentials of the cathodes and the theoretical and experimental discharge potentials of the systems have been determined. The cathodic and anodic overpotentials produced on Al, Fe, HgSt, CrNiSt and Pt were predicted against a platinum anode and a platinum cathode, respectively. The amounts of hydrogen gas produced at different times on the cathodes at a constant potential were measured and the hydrogen yield was calculated. From the data obtained, it is suggested that Pt anode and Al or HgSt cathode, or Al anode and Pt cathode, couples should be employed for the best electrolysis system.     

A maximum power point tracking for photovoltaic-SPE system using a maximum current controller

Processes to produce hydrogen from solar photovoltaic (PV)-powered water electrolysis using solid polymer electrolysis (SPE) are reported. An alternative control of maximum power point tracking (MPPT) in the PV-SPE system based on the maximum current searching methods has been designed and implemented.Based on the characteristics of voltage–current and theoretical analysis of SPE, it can be shown that the tracking of the maximum current output of DC–DC converter in SPE side will track the MPPT of photovoltaic panel simultaneously.This method uses a proportional integrator controller to control the duty factor of DC–DC converter with pulse-width modulator (PWM).The MPPT performance and hydrogen production performance of this method have been evaluated and discussed based on the results of the experiment.     

A waste heat recovery system development and analysis using ORC for the energy efficiency improvement in aluminium electrolysis cells

The present work investigates an active waste heat recovery system for the side walls of the aluminium electrolysis cells, enabling utilization of the extracted heat in power generation. This will potentially lead to energy efficiency improvement in the primary aluminium production industry and an enhanced aluminium production rate. An experimentally validated loop thermosyphon heat pipe model was used for heat extraction from the cell side wall. Boosting system thermal efficiency through waste heat recovery, by means of a heat utilization system, and increasing the level of control, as well as thermal equilibrium, stand as the main addressed objectives of the current study, which consequently result in an increased aluminium production rate. An organic Rankine cycle is incorporated into the system, and its performance is evaluated, taking into consideration the operating situations in terms of available temperature and thermal power range.     

FeOOH–CoS composite catalyst with high catalytic performances for oxygen evolution reaction at high current density

Water electrolysis is an efficient approach for high-purity hydrogen production. However, the anodic sluggish oxygen evolution reaction (OER) always needs high overpotential and thus brings about superfluous electricity cost of water electrolysis. Therefore, exploiting highly efficient OER electrocatalysts with small overpotential especially at high current density will undoubtedly boost the development of industrial water electrolysis. Herein, we used a simple hydrothermal method to prepare a novel FeOOH–CoS nanocomposite on nickel foam (NF). The as-prepared FeOOH–CoS/NF catalyst displays an excellent OER performance with extremely low overpotentials of 306 and 329 mV at 500 and 1000 mA cm⁻² in 1.0 M KOH, respectively. In addition, the FeOOH–CoS/NF catalyst can maintain excellent catalytic stability for more than 50 h, and the OER catalytic activity shows almost no attenuation no matter after 1000 repeated CV cycles or 50 h of stability test. The high catalytic activity and stability have exceeded most non-noble metal electrocatalysts reported in literature, which makes the FeOOH–CoS/NF composite catalyst have promising applications in the industrial water electrolysis.     

Low voltage water electrolysis: Decoupling hydrogen production using bioelectrochemical system

Decoupling water electrolysis using mediator is an interesting way to produce pure hydrogen. The present work validates the proof of concept of decoupled electrolyser associated with a bioelectrochemical system (MFC-DES) through a redox flow mediator (potassium hexacyanoferrate (KHCF)). Low voltage (1 V) hydrogen production was achieved with a current density up to 25 mA cm^?2. Regeneration of the mediator was performed by glucose fed microbial fuel cells. The oxidation rate of KHCF in the electrolyser is, at least, an order of magnitude higher than the reduction rate in MFC cascade fed system. MFC-DES is thus a promising set up as it desynchronizes limited microbial rate and hydrogen production, generate value from wastewater and reduce energetic cost of water electrolysis.     

An investigation on the optimisation of electrochemically pigmented aluminium oxide selective collector coatings

In order to produce selective coatings on aluminium substrates to be used as absorber plates in high efficiency solar collectors, nickel pigmentation has been applied to anodically oxidized surfaces. Optical and structural properties of electrochemically formed aluminium oxide films as function of electrolysis conditions such as, applied current, pH, temperature and concentration of metal ions have been examined using electron spectroscopy and scanning electron microscopy. The optimisation of the absorptivity/emissivity ratio of the surfaces in terms of preparation conditions is described. Nickel pigmentation of porous aluminum surfaces was also investigated as a function of electrochemical pigmentation conditions. Mechanisms contributing to selectivity in anodically produced oxides and electrodeposits are discussed.