Thermal spray coating on conductor rolls in electroplating line

In electroplating lines,many conductor rolls are installed in electroplating bath.Typical electroplatings are tin plating(ETL) and zinc plating(EGL),and from required product qualities,a vertical cell for the former and a horizontal cell for the latter is often used.Generally,chrome plating or WC cermet thermal spray coating is applied to stainless steel conductor roll in ETL for prolonging service life by improvement of wear resistance and corrosion resistance.On the other hand,Hastelloy type alloy substrate is used for conductor rolls in EGL due to severe corrosion environment of electro plating solution.Thermal spray coating is effective for reducing wear,but there are many cases where the coating cannot complete expected service life when corrosion becomes an issue.In this study,thermal spray coating for ETL conductor roll and development of the coating for EGL conductor roll to meet expected service life are described.

A New Approach Based on Iterative Method for the Characterization of a Micro-Strip Line with Thick Copper Conductor

In this work, we applied two electromagnetic models for the characterization of a planar structure including a flat, thick copper conductor. Indeed the first model is consisted by modeling two metal ribbons without bulkiness, placed one above the other at a distance of h2 equal to the thickness of the thick conductor. This approach has been implemented and tested by the iterative method. The results of simulations have been compared with those calculated by the Ansoft HFSS software, and they are in good concordance, validating the method of analysis used. The second model is based on the calculation of the effective permittivity of the medium containing the thick conductor. This medium consists of a metallic region of complex relative permittivity , the rest of this medium is filled with air er2 = 1. The effective permittivity eeff calculated from these two relative permittivity er2 and . Comparing the simulation results of this new formulation of the iterative method with those calculated by the software Ansoft HFSS shows that they are in good matching which validates the second model.

A 600-m Jacketing Line of Cable-In-Conduit Conductor (CICC) and the First 600-m Dummy Cable

A cable-in-conduit conductor(CICC ) production line was designed and constructed in Institute of Plasma Physics of Chinese Academy of Sciences (IPPCAS) by the end of 2000. It can produce a length of 600 meters and three kinds of sections of 20.8±0. 1×20.8±0.1, 20.4±0. 1×20.4± 0.1 and 18.6±0.1×18.6±0.1mm2. If the rollers of the shaping machine are changed, it can also produce other sizes of CICCs. So-called inserting-cable technology is adopted in this production line, where the procedures consist of tube pre-treatment (cleaning, pressure and leakage testing, end cutting), conduits butt-welding, six kinds of quality checking (endoscopy, dye penetration, pressure control, leakage testing, ultrasonic inspection and X-ray testing), cable inserting, shaping (compacting & squaring), pre-bending & winding and final checking. Now all the instruments and facilities required for these technologies have been installed and got ready. Some key technologies have been explored and good results obtained. Some short samples were produced and a 600 meters long sample was made out in August, 2001.

Rigorous Electromagnetic Modeling of a Micro Strip Line Incorporating a Flat and Thick Metallic Conductor Based on the Skin Effect Phenomenon

In most studies of microstrip circuits, the majority of researchers assume that the microstrip structures studied have flat metallic conductors of finite widths but without thickness. But in reality these types of structures integrate metallic copper conductors of different thicknesses. If we neglect this thickness we introduce error in the electrical parameters of the microstrip structure, which affects the effective permittivity, the characteristic impedance, the adaptation of the circuit, the resonance frequency, etc. Given the importance of this parameter (thickness of the metal of micro rubon structures), rigorous electromagnetic modeling of the thick micro rubon line based on the skin effect phenomenon (In fact at high frequency the skin effect phenomenon occurs and the current only flows on the periphery of the conductor) has been proposed to improve the studied electric model and ensure the increase in the precision of the analysis method used: Wave concept iterative process. The good agreement between the simulated and published data justifies the improvement of the model.

Research on Breeze Vibration Law and Modal Identification Method of Conductor Considering Anti-Vibration Hammer Damage

In the harsh environment,the structural health of the anti-vibration hammer,which suffers from the coupled effects of corrosion and fatigue damage,is significantly reduced.As part of the conductor structure,the anti-vibration hammer is rigidly attached to the conductor,effectively suppressing conductor vibration.The conductor’s breeze vibration law and natural modal frequency are altered damage to the anti-vibration hammer structure.Through built a vibration experiment platform to simulate multiple faults such as anti-vibration hammer head drop off and position slippage,which to obtained the vibration acceleration signal of the conductor.The acceleration vibration signal is processed and analyzed in the time and frequency domains.The results are used to derive the breeze vibration law of the conductor under multiple faults and propose an anti-vibration hammer damage online monitoring technology.The results show that the vibration acceleration value and vibration intensity of the conductor are significantly increased after the anti-vibration hammer damage.The natural frequency increases for each order,with an absolute change ranging from 0.15 to 6.49 Hz.The anti-vibration hammer slipped due to a loose connection,the 1st natural frequency increases from 8.18 to 16.62 Hz.Therefore,in engineering applications,there can be no contact to determine the anti-vibration hammer damage situation by monitoring the modal natural frequency of the conductor.This is even a tiny damage that cannot be seen.This method will prevent the further expansion of the damage that can cause accidents.

Performance Evaluation for Medium Voltage MIMO-OFDM Power Line Communication System

Power line communication(PLC)provides intelligent electrical functions such as power quality measurement,fault surveys,and remote control of electrical network.Most of research works have been done in low voltage(LV)scenario due to the fast development of in-home PLC.The aim of this paper is to evaluate the link-level performance of a medium voltage(MV)MIMO-OFDM communication system based on transmission link under underground power line channel.The MIMO channel is modeled as a modified multipath model in the presence of impulsive noise and background noise.We first perform a measurement on the practical MV MIMO channel parameters for a section of buried cable of 1 km long in Ganzhou city,Jiangxi province,China.Based on the measured channel,we design the frame structure based on an IEEE standard for broadband over power line networks[1]to support MV MIMO-OFDM transmission.According to designed frame structure,we design an encoder and a decoder for a dual binary tail-biting turbo code and optimize some key decoder parameters for low bit error rate performance.Finally,the link-level performance for both spatial multiplexing and spatial diversity are evaluated.Numeral results show that MV MIMO-OFDM is a promising approach to provide both high data rate and link reliability for PLC.

Implementation of Dynamic Line Rating in a Sub-Transmission System for Wind Power Integration

Based on conventional static line rating method, the actual current carrying capability of overhead conductors cannot be judged. Due to continuous increment in electricity demand and the difficulties associated with new line constructions, the overhead lines are therefore required to be rated based on a method that should establish their real-time capability in terms of electricity transmission. The method used to determine the real-time ampacity of overhead conductors not only can enhance their transmission capacity but can also help in allowing excessive renewable generation in the electricity network. In this research work, the issues related to analyzing an impact of wind power on periodical loading of overhead line as well as finding its static and dynamic ampacities with line current are investigated in detail. Moreover, the investigation related to finding a suitable location for the construction of a 60 MW wind farm is taken on board. Thereafter, the wind park is integrated with a regional grid, owned by Fortum Distribution AB. In addition to that, the electricity generated from the wind park is also calculated in this project. Later on, the work is devoted to finding the static and dynamic line ratings for “VL3” overhead conductor by using IEEE-738-2006 standard. Furthermore, the project also deals with finding the line current and making its comparison with maximum capacity of overhead conductor (VL3) for loading it in such a way that no any violation of safe ground clearance requirements is observed at all. Besides, the line current, knowing the conductor temperature when it transmits the required electricity in the presence of wind power generation is also an important factor to be taken into consideration. Therefore, based on real-time ambient conditions with actual line loading and with the help of IEEE-738-2006 standard, the conductor temperature is also calculated in this project. At the end, an economic analysis is performed to evaluate the financial advantages related to applying the dynamic line ratings approach in place of traditional static line ratings technique across an overhead conductor (VL3) and to know how much beneficial it is to temporarily postpone the rebuilding and/or construction of a new transmission line. Furthermore, an economic analysis related to wind power system is taken into consideration as well to get familiar with the costs related to building and connecting a 60 MW wind farm with the regional grid.

兼顾传输功率和衰减因素的同轴线半径比优化方法

针对传统的通用型同轴线产品设计、制造基础理论缺陷和目前微波采油现场利用地下石油管构建超长、功率容量大及能量损耗小的井筒同轴线工程需求,进行通用型同轴线结构优化理论和设计方法研究;突破经典的单因素优化方法约束,基于同轴线上传输功率、能量损耗与衰减系数三者之间固有的物理关系,构造兼顾最大传输功率和最小衰减系数双重因素影响的目标函数数学模型;提出同轴线半径比优化设计方法。结果表明:通用型同轴线的外、内导体半径比最优值为2.11,特性阻抗标称值为45Ω;同轴线传输特性对其导体半径比的变化很敏感,应用经典的单因素优化结果不能满足使用要求,只有兼顾最大传输功率和最小衰减系数双重因素影响才能使通用型同轴线具有通用性功能,本文的理论结果与同轴线单模传输公式相结合,构成了完整的通用型同轴线结构优化设计理论体系。

Research on Total Electric Field for DC Lines Converted from Double-Circuit AC Lines

With rapid growth of power demand, transmission capacity is also in urgent need of upgrading. In some cases, converting existing AC transmission lines to DC lines can Improve the transmission capacity and reduce the construction investment. In this paper, the upstream finite element method was expanded to calculate the total electric field of same tower multi-circuit DC lines converted from double-circuit AC lines, and the validity of the algorithm was confirmed by experiments. Taking a DC line converted from a typical same tower 500 kV double-circuit AC transmission line as an example, the surface electric field and the ground total electric field in different pole conductor arrangement schemes were calculated and analyzed, and the critical height of pole conductors for DC lines in residential and non-residential area were determined. Then, the corridor width of DC and AC lines at critical height in residential and non-residential areas before and after AC-DC line transformation were compared. The results indicate that for DC lines converted from common 500 kV double-circuit AC lines, the ground total electric field can meet the requirements of corresponding standard with appropriate pole conductor arrangement schemes.

基于分数阶传输线模型的轨道电路暂态分析

为了准确分析暂态信号对ZPW-2000A型轨道电路的影响,考虑传输线中由集肤效应引起的频变损耗问题,建立轨道电路分数阶多导体传输线(Multi-conductor Transmission Line,MTL)模型,针对ZPW-2000A轨道电路高频损耗下暂态响应分析,提出在时域内对轨道电路接收端电压的求解方法.基于传输线理论建立轨道电路传输线系统模型,根据得到的模型建立分数阶传输线方程并对其进行求解.首先,在空间域上利用紧凑有限差分法(Compact Finite Difference Method,CFD)将轨道电路分数阶传输线模型的偏微分方程组离散为常微分方程组;其次,利用G-L分数阶定义将以上方程组转化为整数阶常微分方程组;最后,利用精细积分与递归卷积相结合的方法,得到传输线上每点的电压与电流响应.在双指数信号激励下,通过与状态变量法对比验证了该方法的准确性,两种求解方法的误差在7%以内,且本文方法耗时较短.分析了不同暂态信号输入下轨面过电压变化规律,发现信号频率越大,轨面过电压幅值越小;道床电阻越大,轨面过电压幅值越大且信号从衰减到稳定的时间越长.本文方法可以准确、高效地分析高频损耗下ZPW-2000A型轨道电路暂态响应.

基于绝对节点坐标法的架空线断线工况动力学计算

为了计算架空线断线工况下的动力学变化特性,考虑架空线的绞制几何结构及其初始构型的布置特点,以绝对节点坐标法为基础,建立了架空线单元,推导了架空线单元的质量矩阵和弹性力矩阵,给出了架空线的系统动力学方程。针对钢芯铝绞线的绞制几何结构,给出了其对应的轴向、弯曲刚度计算公式。通过仿真计算得到线缆的运动图像,设计试验验证了算法模型的可靠性。结合实际架空线初始位形和初始应力特点,对不同初始应力下的架空线断线工况动力学问题进行仿真分析,绘制了悬挂点处的受力时程曲线并对曲线进行了频谱分析,研究了初始应力对断裂架空线运动过程以及悬挂点受力的影响规律。

基于ABAQUS的输电线找形与分裂导线模拟研究

架空输电线是输电塔-线体系的重要组成部分,但由于几何非线性特征强,难以直接得到输电线的初始形态。基于ABAQUS有限元分析软件,提出更新形状法和更新张力法两种输电线找形方法,建立单导线模型作为算例进行分析与对比。研究结果表明,两种找形方法均具有很高的精确性,而在操作性和适用范围方面存在区别。由于新建输电线路的需求,分裂导线越来越多地被应用于输电线路中,考虑间隔棒与分裂导线间的耦合作用,提出一种分裂导线的模拟方法,可以实现分裂导线的精细模拟,并通过简化模型和精细化模型的动力特性对比,验证模拟的准确性。提出的输电线找形方法和分裂导线模拟方法可以为输电线路精确建模和分析提供参考。

基于多导体传输线的高速铁路站内机车信号邻线干扰研究

ZPW-2000系列轨道电路广泛应用于高速铁路区间及站内,其中站内邻线干扰问题较为复杂。为防止高速铁路站内机车信号邻线干扰导致CTCS-2和CTCS-3级列控系统车载设备误动作的情况,对站内邻线干扰的分析是非常必要的。基于多导体传输线微分方程,推导多导体传输线的阻抗差分方程和导纳差分方程。在多导体传输线差分方程的基础上,进一步建立包括轨道区段、发送设备和接收设备等的轨道电路邻线干扰模型,并对比现场数据和仿真数据,验证模型的正确性。最后,通过对机车信号邻线干扰模型的计算仿真,研究区段并行长度、线路间距、线路角度、道砟电阻和功放电压等因素对于机车信号邻线干扰数值的影响规律,主要结论为:对于同向载频干扰,机车信号干扰电流最大值随着线路间距和线路角度增大而逐渐减小,设计时线路间距不宜小于5 m,合理设置道岔区段可降低干扰;随着功放电压和道砟电阻增大而逐渐增大,设计时应采用低功放电压设计和当地可能达到的最大道砟电阻。

大风区接触网线路参数对附加导线舞动的影响

针对大风环境下兰新高速铁路接触网附加导线发生剧烈舞动以及线间放电的现象,依据接触网附加导线结构特点,建立了附加导线有限元计算模型,并对附加导线进行找形计算。采用谐波叠加法模拟接触网附加导线处的随机风场,并对导线模型施加风荷载,利用无条件稳定Newmark法以及荷载增量法,分析接触网线路参数对附加导线舞动及线间距离的影响规律,并给出相应的舞动防治措施。结果表明:40 m及更小档距对导线在低风速及高风速下的舞动均有明显的抑制效果;将附加导线运行张力提高至6.5 kN,导线阻尼比提高至1.5%及以上能有效降低两条导线的舞动剧烈程度;接触网附加导线的档距过大,运行张力及阻尼比过小,将导致导线舞动时悬挂点张力过大,易引起导线掉线、断线等事故;随附加导线档距减小、运行张力及阻尼比增大,线间最小距离呈递增趋势;不同线路参数下(档距、运行张力及阻尼比)附加导线舞动时线间最小距离均随风速增大出现减小趋势。本研究可为兰新高铁大风区段接触网附加导线舞动及线间放电的防治提供有效的理论依据。

双差模非屏蔽线缆回路的电磁串扰研究

随着电气化的发展,电气与电子系统中的电磁兼容问题越来越被重视,为了消除或抑制电磁耦合的影响,实现设备或元件电磁兼容的工作,有必要对线缆间的串扰进行研究。但目前少有相关研究关注独立的发射回路与接收回路构成的双差模回路间的电磁串扰问题。提出了一种基于多导体传输线理论的五导体传输线模型,并基于此研究了双差模非屏蔽线缆回路间的串扰问题。该方法根据耦合机理,首先建立单位长度五导体传输线等效模型,然后根据有限差分的方法列写基尔霍夫方程组,最后补充边界条件后求解得到串扰的频域解。将串扰计算结果与CST软件仿真结果进行对比,验证了该模型和计算方法的可行性与有效性,经计算分别研究了感性耦合与容性耦合,分析得到了不同因素对线束间串扰的影响规律,可为实际工程中采取措施抑制线缆间串扰提供指导,体现出该模型的先进性。

兼顾电缆线路效率和可靠性的载流量动态阈值研究

针对当前配电网电缆为了运行可靠性,多采用较低载流量的固定阈值方法,电缆利用率低的问题,本文提出了一种载流量动态阈值的方法。该方法从理论上研究电缆线路载流量与导体温度的关系,通过实际运行的电缆工程的实测数据量化电缆载流量与导体温度的函数关系,并测定电缆线路的基准阈值,以此实现线路的阈值动态化计算。算法应用于智能电缆测控系统的动态阈值监测功能模块,线路所得实际运行数据验证了本方法的有效性。

基于多导体传输线理论的配电网电力电缆载波模型降阶分析

为降低配电网电力电缆载波模型复杂程度,首先,根据配电网常用三芯XLPE绝缘电力电缆结构,结合电力电缆三相金属护套相互接触的实际,以三相金属护套为整体进行分析,将电力电缆7阶多导体传输线载波模型降为5阶。接着,根据配电网终端电力电缆金属护套、铠装直连接地的特点,将其进行等效处理,并分析了等效单位长度参数矩阵各元素与实际参数的关系,再次将配电网电力电缆5阶载波模型降为4阶。仿真试验验证了降阶分析的正确性,电力电缆载波模型的两次降阶,显著降低载波模型复杂程度,降低运算量提升分析速度,为载波通信在电力电缆传输中的进一步分析提供参考。

正极性操作冲击电压下含悬浮导体长空气间隙放电发展过程

带电作业组合间隙是典型的含悬浮导体长空气间隙,含悬浮导体长空气间隙放电机理研究对提升带电作业安全性具有重要意义。为此搭建了棒-棒-板含悬浮导体长空气间隙放电观测平台,开展了悬浮导体位于不同位置的间隙放电观测试验,获得了施加电压、高电位放电电流以及放电光学图像等数据,研究了间隙的放电发展过程。研究结果表明,含悬浮导体长空气间隙这2个子间隙的放电会同时进行并相互影响,子间隙1放电主要由下行先导-流注体系和上行流注组成,子间隙2放电主要由先导-流注体系组成;悬浮导体位置会影响放电发展各阶段的起始时刻和放电发展时间;悬浮导体在任意位置时,放电从子间隙1起始,子间隙2中放电在子间隙1击穿前起始,子间隙2击穿不早于子间隙1击穿;子间隙1流注-先导转化所需临界电荷为0.26μC,与长空气间隙相似;预放电电流幅值、先导发展速度等放电发展特征与长空气间隙存在差异。

一种基于PLC的智能换炉车控制系统设计

采用西门子S7-1500PLC,通过Profinet与V90驱动器通讯,控制伺服电机初步定位、接近开关找准位置二次定位、机械插销准确限位三种方式相结合,设计了一种实用高效的智能换炉车控制系统。换炉车运行平稳、快速且可靠,大大提升了换炉效率。

基于光纤传感稳态热容平衡模型的架空线路导线温度监测

架空线路温度监测过程中,受环境温度、日照等因素的影响,导致其监测数据失真,降低监测准确度。提出基于光纤传感器的架空线路导线温度监测方法。建立架空线路导线的稳态热容平衡模型,分析影响导线温度相关因素。通过光纤温度传感器得到热膨胀的反应系数,计算求得光纤布拉格光栅对温度变化的灵敏度系数,构建传感稳态热平衡方程。结合环境温度、风速和日照辐射等参数,利用导线温升公式计算出传感导线各部位热阻值,获得相对应温度监测数据,实现架空线路导线温度监测。实验结果表明,所提方法在不影响线路正常运行情况下,实验测得导线上表面、侧方位和下表面的温度分别为27.8℃、26.6℃和23.4℃,温度监测准确,误差小。