Closed circle DNA algorithm of change positive-weighted Hamilton circuit problem

Chain length of closed circle DNA is equal. The same closed circle DNA＇s position corresponds to different recognition sequence, and the same recognition sequence corresponds to different foreign DNA segment, so closed circle DNA computing model is generalized. For change positive-weighted Hamilton circuit problem, closed circle DNA algorithm is put forward. First, three groups of DNA encoding are encoded for all arcs, and deck groups are designed for all vertices. All possible solutions are composed. Then, the feasible solutions are filtered out by using group detect experiment, and the optimization solutions are obtained by using group insert experiment and electrophoresis experiment. Finally, all optimization solutions are found by using detect experiment. Complexity of algorithm is concluded and validity of DNA algorithm is explained by an example. Three dominances of the closed circle DNA algorithm are analyzed, and characteristics and dominances of group delete experiment are discussed.

Using Automation Controller System and Simulation Program for Testing Closed Circuits of Mini-Sprinkler Irrigation System

The field experiments were conducted at the experimental farm of Faculty of agricultural, southern Illinois University SIUC, USA. The project makes the irrigation automated. With the use of low cost sensors and the simple circuitry makes currently project a low cost product, which can be bought even by a poor farmer. This research work is best suited for places where water is scares and has to be used in limited quantity and this proposal is a model to modernize the agriculture industries at a mass scale with optimum expenditure. In the field of agricultural engineering, use of sensor method of irrigation operation is important and it is well known that closed circuits of Mini-sprinkler irrigation system are very economical and efficient. Closed circuits are considered one of the modifications of Mini-sprinkler irrigation system, and added advantages to Mini-sprinkler irrigation system because it can relieve low operating pressures problem at the end of the lateral lines. In the conventional closed circuits of Mini-sprinkler irrigation system, the farmer has to keep watch on irrigation timetable, which is different for different crops. Using this system, one can save manpower, water to improve production and ultimately profit. The data could be summarized in following: Irrigation methods under study when using lateral length 60 mcould be ranked in the following ascending order according the values of the predicted and measured head losses CM1M-SIS CM2M-SIS.The correlation (Corr.) coefficients were used to compare the predicted and measured head losses along the lateral lines of all the closed circuits designs. Generally, the values of correlation analysis were (>0.90) were obtained with 0% field slope60 mlength (experimental conditions) for all closed circuits.The interaction between irrigation methods: at the start there are significant differences between CM2M-SIS and CM1M-SIS.

Energy and water saving by using modified closed circuits of drip irrigation system

The aim of this research was determine the en- ergy and water use efficiencies under the modification of closed circuit drip irrigation systems designs. Field experiments carried out on transgenic maize (GDH, LL3), (Zea Mays crop) under two types of closed circuits: a) One manifold for lateral lines or Closed circuits with One Manifold of Drip Irrigation System (CM1DIS);b) Closed circuits with Two Manifolds of Drip Irrigation System (CM2DIS), and c) Traditional Drip Irrigation System (TDIS) as a control. Three lengths of lateral lines were used, 40, 60, and 80 meters. PE tubes lateral lines: 16 mm diameter;30 cm emitters distance, and GR built-in emitters 4 lph when operating pressure 1 bar under Two levels slope conditions 0% and 2%. Experiments were conducted at the Agric. Res. Fields., Soil and Plant & Agric. System Dept., Agric. Faculty, Southern Illinois University, Car- bondale (SIUC), Illinois, USA. Under 0% level slope when using CM2DIS the increase percent of Energy Use Efficiency (EUE) were 32.27, 33.21, and 34.37% whereas with CM1DIS were 30.84, 28.96, and 27.45% On the other hand when level slope 2% were with CM2DIS 31.57, 33.14, and 34.25 while CM1DIS were 30.15, 28.98, and 27.53 under lateral lengths 40, 60 and 80 m respectively relative to TDIS. Water Use Efficiency (WUE) when level slope 0% under CM2DIS were 1.67, 1.18, and 0.87 kg/m3 compared to 1.65, 1.16, and 0.86 kg/m3 with CM1DIS and 1.35, 1.04, and 0.75 kg/m3 with TDIS whereas with level slope 2% when using CM2DIS were 1.76, 1.29, and 0.84 kg/m3 compared to 1.77, 1.30, and 0.87 kg/m3 with CM1DIS and 1.41, 1.12, and 0.76 kg/m3 (for lateral lengths 40, 60, and 80 meters respectively). Water saving percent varied widely within individual lateral lengths and between circuit types relative to TDIS. Under slope 0% level CM2DIS water saving percent values were 19.26, 12.48, and 14.03%;with CM1DIS they were 18.51, 10.50, and 12.78%;and under slope level 2% with CM2DIS they were 19.93, 13.26, and 10.38% and CM1DIS were 20.49, 13.96, and 13.23% (for lateral lengths 40, 60, 80 meters respectively). The energy use efficiency and water saving were observed under CM2DIS and CM1DIS when using the shortest lateral length 40 meters, then lateral length 60 meters, while the lowest value was observed when using lateral length 80 meters this result depends on the physical and hydraulic characteristics of the emitters, lateral line uniformity, and friction losses. CM2DIS was more energy use efficiency, EUE, water saving, and WUE than either CM1DIS or TDIS.

Effect of closed circuits drip irrigation system and lateral lines length on growth, yield, quality and water use efficiency of soybean crop

Field experiment was conducted for one growing season (2012) in clay loam soil at the Experimental Farm of Faculty of Agriculture, Southern Illinois University at Carbondale (SIUC), USA on soybean crop to study the effect of: 1) the closed drip irrigation system: closed circuits with one and two a manifolds for lateral lines (CM1DIS;CM2DIS) and traditional drip irrigation system (TDIS) as a control;and 2) lateral lines length (LLL): LLL1, LLL2 and LLL3 (40, 60,80 m) on soybean growth, yield, oil, protein content and water use efficiency. Plants were drip irrigated every 4 days. N, K2O and P2O5 fertilizers were added via irrigation water. Data obtained could be outlined as follows: 1) According to the mean values of soybean crop growth (leaf area;plant height), yield (grain and straw), both oil and protein content and water use efficiency, the treatment used could be ranked in the following ascending orders: TDIS < CM1DIS < CM2DIS and LLL3 < LLL2 < LLL1;2) Differences in the means of the studied data among treatments used were significant at the 1% level;3) The effects of the DIC × LLL on the data obtained were significant at the 1 % level;And 4) the highest values of the obtained data and the lowest ones were achieved in the following interactions: CM2DIS × LLL1;TDIS × LLL3, respectively.

Modification of water application uniformity among closed circuit trickle irrigation systems

The aim of this research was determine the ma- ximum application uniformity of closed circuit trickle irrigation systems designs. Laboratory tests carried out for Two types of closed circuits: a) One manifold for lateral lines or Closed circuits with One Manifold of Trikle Irrigation System (COMTIS);b) Closed circuits with Two Manifolds of Trikle Irrigation System (CTMTIS), and c) Traditional Trikle Irrigation System (TTIS) as a control. Three lengths of lateral lines were used, 40, 60, and 80 meters. PE tubes lateral lines: 16 mm diameter;30 cm emitters distance, and GR built-in emitters 4 lph when operating pressure 1 bar. Experiments were conducted at the Agric. Eng. Res. Inst., ARC, MALR, Egypt. With COMTIS the emitter flow rate was 4.07, 3.51, and 3.59 lph compared to 4.18, 3.72, and 3.71 lph with CTMTIS and 3.21, 2.6, and 2.16 lph with TTIS (lateral lengths 40, 60, and 80 meters respectively). Uniformity varied widely within individual lateral lengths and between circuit types. Under CTMTIS uniformity values were 97.74, 95.14, and 92.03 %;with COMTIS they were 95.73, 89.45, and 83.25 %;and with TTIS they were 88.27, 84.73, and 80.53 % (for lateral lengths 40, 60, 80 meters respectively). The greatest uniformity was observed under CTMTIS and COMTIS when using the shortest lateral length 40 meters, then lateral length 60 meters, while the lowest value was observed when using lateral length 80 meters this result depends on the physical and hydraulic characteristics of the emitter and lateral line. CTMTIS was more uniform than either COMTIS or TTIS. Friction losses were decreased with CTMTIS in the emitter laterals at lengths 40 meters compared to TTIS and COMTIS. Therefore, differences may be related to increased friction losses when using TDIS and COMDIS.

Process Analysis of Double Circuit Transmission Line Trip-out on the Same Tower Due to Lightning

In recent years,several failures of double circuit transmission line on the same tower due to lightning were happened in Beijing power grid.Although it can be reclosed successful,the lightning strike caused a grave threat to the power grid security.The cause of the accident and the accident process were studied for the sake of further understanding of the impact of lightning on power grid.As an example,110 kV double circuit transmission line(Xilong-line) was analyzed.At first,the system topology was given.Through the analysis on relay protection actions and the fault recorder data,over voltage on the insulator strings was calculated.Based on the analysis and the calculation,accident cause and the process were presented respectively.Secondly,it comes to the conclusion that the lightning failure was caused by counterattack.The wave of the lightning over voltage would spread to the not grounded neutral point of the transformers,and make the neutral protective gap breakdown,then cause freewheeling with the frequency of 50 Hz.As results of the relay protection,the double circuit transmission line all tripped out.Finally,the causes of the accident were proposed that included terrain features,large corner towers,strong thunderstorm weather and poor grounded contact of the tower.

Dynamic modeling and analysis of the closed-circuit grinding-classification process

Mathematical models of the grinding process are the basis of analysis, simulation and control. Most existent models in- cluding theoretical models and identification models are, however, inconvenient for direct analysis. In addition, many models pay much attention to the local details in the closed-circuit grinding process while overlooking the systematic behavior of the process as a whole. From the systematic perspective, the dynamic behavior of the whole closed-circuit grinding-classification process is consid- ered and a first-order transfer function model describing the dynamic relation between the raw material and the product is established. The model proves that the time constant of the closed-circuit process is lager than that of the open-circuit process and reveals how physical parameters affect the process dynamic behavior. These are very helpful to understand, design and control the closed-circuit grinding-classification process.

Close Neighbors Plus Relatives──An unforgettable Trip to the Philippines

At the invitation of the.Asian Center of the Philip-pine University,a five-mem-berCAFIU delegation visited the Philippines.The host high-ly regarded our visit,gave us a W arm and courteous recep-tion.Mr.Estrada.

手跳线路分相断路器失灵时预防事故扩大的方法

现场出现了几起手跳分相断路器时一相或两相断路器失灵的情况,但目前的规范并未要求手跳断路器失灵时启动失灵保护,若由零序过流保护动作切除负荷电流,可能导致事故扩大。目前南网220 kV线路保护通过修改软件实现了三相不一致和单相运行三跳动作后远跳线路对侧,但国网以及南网有些地区的保护不具备软件升级条件,提出了将手跳继电器触点和断路器三相位置不一致状态触点串联后接入纵联电流差动保护的其他保护动作开入方法。该方法简单可靠,便于实施。

断路器碳陶瓷合闸电阻能量耐受及失效特性

合闸电阻在大能量注入下的热电耐受及性能稳定是超/特高压交流系统断路器安全稳定运行的关键因素。为此通过开展合闸电阻模拟能量注入实验,并建立碳陶瓷复合材料微观结构热电耦合仿真模型,研究碳陶瓷电阻在不同强度能量注入下的材料温升、动态导电、性能劣化及结构破坏行为,分析碳陶瓷合闸电阻的能量耐受及失效机理。研究发现,碳陶瓷电阻具有随温度变化的动态导电特性,导通电阻及恢复电阻随能量注入强度的增加而减小;在大能量注入下,碳陶瓷电阻劣化及损伤模式包含恢复电阻下降、侧面绝缘击穿及电阻体碎裂。根据大能量注入下电阻内部多物理场分布仿真结果,结合碳陶瓷复合材料微观结构观察及电接触导电机制分析,揭示来源于碳陶瓷电阻内部电流密度、温度及热应力不均匀分布的性能劣化及结构破坏电热正反馈物理机制。

SF_(6)断路器触头劣化过程合闸预击穿特性研究

电容器组投切断路器触头烧蚀劣化后会改变合闸预击穿时间,这不仅会影响选相合闸效果,同时也说明预击穿电弧持续时间可作为衡量触头烧蚀状态的指标之一。建立了126 kV SF_(6)断路器灭弧室内合闸预击穿过程电—流体耦合仿真模型,研究了触头劣化过程中合闸预击穿特性,并提出了预击穿时间带电检测方法。结果表明:合闸过程中场强最大点总是出现在静弧触头表面;灭弧室内SF_(6)气体密度几乎保持不变;110 kV电压等级相电压下,触头预击穿电弧持续时间随烧蚀程度变化的试验值与仿真值吻合良好。从电场畸变角度解释了随着触头的表面烧蚀劣化程度增大对应预击穿时间的变化规律,结果可为断路器选相合闸策略和触头状态评估提供理论指导。

关于取消新疆电网750 kV断路器合闸电阻可行性的仿真研究

目前,超、特高压输电线路常用合闸电阻吸收能量,并将其作为限制合闸过电压的主要手段,但是带有合闸电阻的断路器不仅造价昂贵,而且还存在运行可靠性差、故障率高等缺点,如果能利用低残压、保护性能优异的金属氧化物避雷器替代合闸电阻来限制操作过电压,不仅可以降低成本,还能简化断路器操纵机构以提高电力系统运行的可靠性。文中以新疆电网最长距离的750 kV线路为研究对象,通过沿线安装多组避雷器的方式,将沿线最大2%合闸过电压限制到规程规定的1.8 p.u.以内,为新疆电网所有750 kV长距离线路取消断路器合闸电阻的可行性提供了理论依据。

具备限流能力的混合式高压直流断路器拓扑

直流断路器(DCCB)是解决直流系统短路故障的重要手段,针对现有DCCB存在的限流效果差、避雷器使用寿命短和故障隔离速度慢等一系列缺陷,文中提出一种具备限流能力的混合式高压直流断路器拓扑(CLC-HDCCB)方案。CLC-HDCCB载流支路和转移支路采用双桥式结构,具备双向通断能力;限流部分采用限流电阻和限流电感并联限流方式,显著降低了故障电流峰值及上升率;设计泄能电阻在断路过程中将限流电感旁路,减少了避雷器单次开断吸收的能量;对所提CLC-HDCCB方案分断故障电流、正常合闸和分断小电流等直流系统出现的各种工况进行了详细分析,并给出参数选定的方法。最后在PSCAD/EMTDC平台进行仿真验证,结果表明所提CLC-HDCCB方案与现有DCCB方案相比在故障限流、避雷器吸能和故障清除时间等方面具有一定的优势。

用于纳米压电定位平台的电容传感器设计

针对纳米压电定位平台中电阻应变片式传感器无法满足定位精度的问题,设计了一种非接触式测量的双极板电容式位移传感器。首先,详细分析了电容传感器的基本测量原理和闭环控制原理。对电容传感器固有的边缘效应问题进行理论分析,并通过保护环措施消除其影响。在建立电磁仿真参数模型的基础上,带保护环结构的电容仿真值与理想值误差小于1.8%。改进了一种基于有源电桥的高灵敏度运算放大器式电容检测电路,使电路具有更高的分辨率和线性度。通过对该传感器进行标定,其测量范围在0~30μm内,线性度为0.05%,分辨力优于0.01μm。

海外工程中断路器跳闸监视回路设计

海外工程对高压断路器的跳闸监视回路设计要求特殊,如不重视其设计,将耽搁项目工期,造成项目成本的增加。本文着重分析了国内跳闸监视回路设计的原理及弊端,对海外工程中断路器跳闸监视回路的设计弊端提出了解决方案,减少了项目成本,以期为类似项目提供参考。

硫化铅锌矿“优先选铅—选铅尾矿选锌”回收铅锌

内蒙古某硫化铅锌矿主要有价元素为Pb和Zn,含量分别为0.90%和3.23%。采用化学分析、XRD分析和MLA等分析手段对该矿进行详细的工艺矿物研究,并在工艺矿物学研究的基础上开展条件试验和闭路试验。工艺矿物学分析结果表明:在该矿中,方铅矿和闪锌矿为主要目的矿物,二者主要呈稀疏-稠密浸染状分布于脉石矿物间,且嵌布特征较为复杂,局部富集程度不高,嵌布粒度不均,部分方铅矿包裹于闪锌矿中,会对后续浮选作业产生不利影响。脉石矿物主要为钙铁辉石、石英、方解石、绿帘石、钙铝榴石、斜长石和钾长石,另含有少量的绿泥石、白云母和黑云母。采用优先选铅-选铅尾矿选锌—中矿依次返回上一作业的闭路浮选流程进行浮选,最终可获得Pb品位为66.83%、Pb回收率为85.42%的合格铅精矿产品,以及Zn品位为53.26%、Zn回收率为91.53%的合格锌精矿产品,可实现对该硫化铅锌矿的有效利用。

基于动态灰色关联分析法的高压断路器机械故障诊断

高压断路器机械故障成因复杂,机械故障与分合闸线圈电流之间难以找到解析的映射关系。因此引入灰色关联分析法,建立一种高压断路器机械故障诊断模型,进一步通过计算参考数列与比较数列的距离来选择分辨系数,提出一种基于动态分辨系数的灰色关联分析法。该方法不需要大量样本数据,且算法精度不受信号干扰的影响。研究表明,选取铁心卡涩运动的时间参量相关度作为故障诊断特征量能有效诊断出高压断路器机械故障。

断路器选相合闸技术应用综述与展望

目前,选相合闸技术在无功补偿电容器组、特高压线路、滤波器场等场景应用广泛。本文综述了国内外断路器选相合闸技术的研究现状,介绍了断路器选相合闸技术的应用,深入归纳了介质强度下降率(rate of decrease of dielectric strength, RDDS)、温度、间歇时间等各种因素对断路器选相合闸精度的影响,总结了断路器选相合闸的关键技术和问题,分析了断路器合闸动作时间分散性的产生原因,对断路器选相合闸技术的研究提出一些建议。

1100 kV GIS断路器合闸电阻故障检测及分析

断路器的合闸电阻能够有效抑制合闸涌流以及操作过电压,对电网的稳定运行起着重要作用,合闸电阻一旦出现故障,无法正确投入或退出,将会造成巨大的设备和安全事故。由于1100 k V GIS断路器为多断口结构,断口间的配合时序偏差以及各触头弹跳因素的干扰,经常导致合闸电阻特性无法测量,或者测试结果误差较大。针对一起1100 kV GIS断路器合闸电阻预投入时间及阻值无法检测事件展开研究,分析其结构与测试原理,通过提高测试频率获取完整测试波形,推断得出合闸电阻的预投入时间及其阻值无法检测的原因是其中一侧的合闸电阻断口失效。解体检查,发现该断路器其中一侧合闸电阻动触头因固定螺栓断裂而导致该侧动触头脱落,验证了电阻断口失效导致动作特性无法检测的推断。最后从制作工艺、试验项目、试验仪器、检测手段等方面提出相应的建议及改进措施,为同类型设备的工艺管控和故障诊断提供参考。

断路器防跳回路的分析与优化

阐述了操作箱防跳回路和断路器机构防跳回路的工作原理,探讨了操作箱防跳与断路器机构防跳的区别。针对一起断路器防跳回路元件参数失配案例进行探讨,提出了在防跳回路中串接电阻、串接断路器分位辅助接点等改进措施来优化防跳回路,防止断路器在短时间内多次分闸、合闸,为电力系统的安全可靠运行提供更加坚实的保障。