矿井供电防越级跳闸监控系统研究

为更好地防止矿井供电系统发生越级跳闸故障,分析了煤矿供电系统越级跳闸事故的原因,总结了当前煤矿供电系统主要的防越级跳闸方法,并结合实际工作经验提出了一种基于"三位一体"的煤矿供电防越级跳闸监控系统。实际应用结果表明,该防越级跳闸监控系统能有效防范矿井供电系统发生越级跳闸故障,更好地保障矿井供电系统的连续可靠供电。     

基于煤矿智能变电站的防越级跳闸系统设计

针对煤矿多发的越级跳闸难题,构筑了基于智能变电站的煤矿防越级跳闸系统。在确定智能变电站结构及防越级跳闸流程的基础上,对矿用智能保护装置硬件进行了整体框架设计,同时设计了矿用智能保护装置与防越级主机系统软件部分。该防越级跳闸系统能够有效解决越级跳闸难题。     

常村煤矿变电所防越级跳闸系统设计与应用

针对常村煤矿N3采区1#主变电所供电系统经常出现越级跳闸故障的问题,分析了越级跳闸故障产生的可能原因,开展了防越级跳闸系统设计与应用工作.应用结果表明,防越级跳闸系统运行稳定可靠,成功解决了井下供电系统越级跳闸问题,降低了供电系统的运行维护成本,提高了井下用电设备利用率,为企业创造了更多的经济效益.     

矿井高压电网防越级跳闸技术研究

从王村煤业实际供电现状出发,分析了日常生产作业中引发高压电网越级跳闸的原因,并提出了一系列行之有效的防越级跳闸措施,以期能有效预防矿井高压电网越级跳闸故障,进一步保障矿井供电系统的安全可靠运行。     

煤矿供电系统防越级跳闸技术的分析及应用

为了解决矿山发生超级跳闸事故,分析超级跳闸事故发生的原因,主要是由于短路、漏电及电压波动等造成的,通过分析现有的防越级跳闸的方法提出了三位一体供电防越级跳闸监控系统,分别从短路、漏电及电压波动三个角度进行防越级跳闸。通过现场使用验证了其可靠性与快速性,为矿山供电安全提供参考。     

矿井供电系统防越级跳闸技术及应用研究

煤矿供电系统是保障煤炭开采过程中各类电气设备正常平稳运转的关键,通过输送电能给机械设备产生运转动力,实现煤炭物料的开采.目前矿井供电系统容易出现越级跳闸等问题,对供电系统的安全性有较大影响并且容易引发其他故障,造成矿井安全生产事故的发生.对越级跳闸原理和机制进行分析后,提出了基于GOOSE通讯技术的供电系统防越级跳闸技术,对整个系统硬件、软件进行了设计,实现了防越级跳闸技术在实际现场煤矿供电系统中的应用,并取得了良好的效果,能在矿井恶劣的环境中提升供电系统安全性能.     

矿井高压电网防越级跳闸保护系统设计

为解决申南凹矿原有矿井供电系统越级跳闸事故频发问题,基于数字式光纤电流纵联差动保护技术设计了井下供电系统防越级跳闸保护系统,介绍数字式光纤电流纵联差动保护技术工作原理,同时对系统的硬件和软件的设计方案进行分析确定,优化后的供电系统实际应用验证系统的安全性得到了提升,未出现越级跳闸事故,为矿井供电系统安全运行提供保障.     

矿井高压电网防越级跳闸保护系统设计

为解决申南凹矿原有矿井供电系统越级跳闸事故频发问题,基于数字式光纤电流纵联差动保护技术设计了井下供电系统防越级跳闸保护系统,介绍数字式光纤电流纵联差动保护技术工作原理,同时对系统的硬件和软件的设计方案进行分析确定,优化后的供电系统实际应用验证系统的安全性得到了提升,未出现越级跳闸事故,为矿井供电系统安全运行提供保障.     

矿井高压电网防越级跳闸保护系统设计

为解决申南凹矿原有矿井供电系统越级跳闸事故频发问题,基于数字式光纤电流纵联差动保护技术设计了井下供电系统防越级跳闸保护系统,介绍数字式光纤电流纵联差动保护技术工作原理,同时对系统的硬件和软件的设计方案进行分析确定,优化后的供电系统实际应用验证系统的安全性得到了提升,未出现越级跳闸事故,为矿井供电系统安全运行提供保障.     

煤矿供电保护系统技术改造方案研究

目前,常村煤矿供电保护系统存在着定值整定困难以及越级跳闸等问题,这些问题的存在对于供电系统的可靠运行会带来极为不利影响。从常村煤矿目前供电保护系统实际问题出发,分析了常村煤矿供电系统越级跳闸问题具体原因,并且设计了常村煤矿供电保护系统技术改造方案,从实际运行情况来看,常村煤矿供电保护系统经过技术改造之后运行稳定,最大限度地防止了越级跳闸问题出现,值得进一步推广应用。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.