Mechanical Design and Kinematic Simulation of Automated Assembly System for Relay

By means of Solid Works, three-dimensional model of automated assembly system was established, and kinematic simulation based on Solid Works Motion of assembly process for relay was performed. The simulation results proved the feasibility of mechanical design. Eventually, the productivity was estimated based on simulation analysis. The mechanical design provided a solution with high reference value to practical design of automated assembly system for relay.

Teaching Protective Relaying Design and Application Using New Modeling and Simulation Tools

As the smart grid concepts are emphasized lately, the need to modernize the power engineering education is also well recognized. This paper presents a set of newly developed modeling, simulation and testing tools aimed at better understanding of the design concept and related applications for protective relaying and substation automation solutions for the smart grid. Since the smart grid applications require integration of data from multiple IEDs （intelligent electronic devices）, understanding properties of each IED type in detail, as well as their responses to the power system events is needed. In addition, understanding the communication requirements to perform data integration is also important. To illustrate how the mentioned smart grid issues may be taught, the following advanced teaching approaches are presented： （1） Use of modeling and simulation means to better understand interaction between the relays and power system; （2） Use of IED test facilities to better understand performance of physical devices used for protection, monitoring and control; （3） Utilization of communication network modeling tools to simulate the communication network within SAS （substation automation system）. Examples showing the use of proposed techniques for teaching the fundamentals and applications are presented. The examples demonstrate the adequacy and efficiency of the proposed techniques.

A Design of 220 kV Line Protection Action Deduction System Based on Numerical Simulation

Accurate conditions monitoring and early wrong action warnings of relay protection in the Smart Substation is the basic guarantee to realize the normal operation of primary and secondary system of the power grid.At present,the traditional operation and maintenance monitoring methods of relay protections have poor timeliness,while some automatic monitoring methods have insufficient early warning performance,and lack the online action deduction function independent of the actual device.In this paper,a design method of integrated action deduction system including protection logic reasoning and software and hardware operation condition is proposed.The system can receive real-time operation information of protection online,simulate different types of faults,and output the recording information of sub modules belongs to the action deduction system.It can realize the online monitoring of device faults such as deducing the correctness of setting values at a certain time in the future,giving the wrong action warnings and predicting the probability of them as well,which effectively improves the operation and maintenance efficiency of the secondary system in the intelligent substation.

A Portable Multi-functional Real-time Digital Simulator Dedicated to Protective Relay Testing

The paper intfoduces a PC-DSP based real-time digital simulator which is portable in size and aimed at the closed-loop testing of various types of protective relays for their design and application. The simulator can be widely used in not only concerning utilities but also manufacturers and research / certification institutes because of its many functions. The hardware architecture and software implementation of the simulator are described. The main features and functions of the simulator are also

Novel Sensing Hole Recovery with Expanded Relay Node Capability

The occurrence of‘sensing holes’not only hinders seamless data col-lection but also leads to misinterpretation of information in certain areas under extensive data analysis.In order to overcome this,various sensor relocation stra-tegies have been proposed,but the existing relocation strategies revealed pro-blems such as the ping-pong,shaded area,network disconnection,etc.This paper conducted research on relocation protocols in a distributed environment that is very suitable for real-world situations and efficiently recovering the problem of sensing holes.First,a simulation was performed on the distribution of the shaded area for data collection,which is a problem with the existing representative relo-cation protocol.After that,a data collection capability was newly added to the relay node,which had been in charge of only communication between cluster zones so far,and with this additional functionality,the performance of the revised sensor relocation algorithm was dramatically improved to overcome the existing problems.In addition,the performance and validity of the proposed algorithm were verified through various simulations.

基于电-热流场双向耦合的直流继电器温升特性仿真研究

高压直流继电器体积小、散热能力有限,长期工作下存在局部过热的风险,发热严重时甚至影响到接触稳定性和继电器工作寿命。针对200 A直流继电器,综合考虑导体回路通电下欧姆损耗发热,在大空间的自然热对流、热传导以及热辐射、材料电阻率随温度变化等因素,建立继电器在额定工况下电-热流场双向耦合模型,设置电阻率随温度变化函数,进行耦合计算。最后,搭建对应的样机测温平台,对仿真正确性进行验证。结果表明双向耦合结果比单向耦合结果高约5.1%,与实验测量值误差小于6.2%,验证了电热流场双向耦合的有效性。

基于中继保障的分布式海战补给路径优化

分布式海战是未来战争形态发展的必然趋势。与传统海战样式相比,分布式海战作战部署更加灵活,作战区域更广。分布式海战条件下的后勤保障区域分布范围广、保障半径大、分散程度高,传统伴随保障方式难以适应战争形态发展。依托中继保障基地进行递进保障,并运用补给舰编队进行物资转运的补给模式,更加适合分布式海战特点。考虑复杂多变的海洋天气对远距离物资投送带来的极大影响,首先基于不同地理位置的历史天气信息模拟有效波高,然后根据有效波高测算天气因素对舰船航速及补给开销的影响程度,最后触发优化模型与仿真模型之间的反馈并得到优化方案。将优化方案与未触发仿真模型的理想优化结果进行比较,以验证不同策略的性能表现,得到契合实际应用环境的优化方案,从而提高最优路径的鲁棒性,为分布式海战物资补给提供较好的决策支撑。

基于比例继动阀的解耦式制动能量回收

针对纯电动商用车在连续制动时,气源压力偏低会导致驱动轴耦合制动力响应速度变慢,影响制动能量回收效率的问题,提出一种基于比例继动阀的解耦式制动能量回收系统(uncoupled braking energy recovery system,URBS)方案。首先,基于比例继动阀的迟滞特性,采用前馈-单神经元PID控制方法,实现制动气压的准确输出;其次,以电池SOC、车速等为约束条件,根据气源压力信号确定供压模式,并制定解耦式制动能量回收控制策略;最后,基于AMESim,MATLAB/Simulink及TruckSim搭建联合仿真平台,选取单次制动工况与循环工况验证了制动力耦合效果及系统的制动能量回收效果。结果表明,基于比例继动阀的URBS可实现耦合制动力的快速响应,达到稳态压力值75%的时间小于0.1 s,且在中国重型商用车行驶工况和中国重型商用车瞬态工况下有效制动能量回收率分别为10.13%,17.17%。所提URBS方案能有效提高驱动轴耦合制动力的响应速度及耦合精度,可为纯电动商用车气压式URBS方案设计提供参考。

井下表面电磁波协同中继传输方法

在井下进行表面电磁波通信时,中继器布局不合理会导致信号强度减弱,为此,提出了表面电磁波的协同中继传输方法。首先,结合数值模拟与模拟试验结果,分析了表面电磁波的传播特性;然后,利用电场积分方法,建立了井下表面电磁波中继传输系统的数学模型,分析了不同中继器布局和数量对接收机信号强度的影响。研究结果表明,表面电磁波比传统无线电磁波具有更小的衰减和更高的传输速率,可成为一种高效的井下通信方式;应用表面电磁波协同中继传输技术,信号强度可平均提高5.91 dB。研究结果为增大表面电磁波井下通信的传输距离提供了新的技术途径。

工频磁场对继电保护装置模拟信号影响分析

文章针对工频磁场抗扰度试验对继电保护装置模拟信号干扰问题,阐述了工频磁场的试验方法,通过仿真分析了干扰磁场作用于模拟信号回路的骚扰机理,提出了一种模拟信号抗干扰的改进措施,并通过试验验证了该措施对改进模拟信号采集回路抗磁场类干扰的有效性。

LTE-A Relay下行静态系统仿真方法

Relay(无线中继)技术是LTE-Advanced R10(4G移动通信标准)中引入的一项无线多跳技术。在LTE-A的Relay系统性仿真中,需要考虑到宏基站和RN(中继节点)之间的回程链路对系统性能的影响。提出一种针对Relay系统下行性能评估的静态系统仿真的建模方法。模型考虑了Relay回程链路的信道传播和干扰模型,回程链路的无线资源分配,以及回程链路容量对UE(用户设备)调度的影响。对LTE-A relay进行了仿真,仿真结果表明,Relay提高了用户的平均吞吐率和小区边缘用户的吞吐率,不同的回程链路资源配置方案对Relay的性能有很大影响。

油浸式电力变压器内部游离气体运动汇集规律

轻瓦斯保护可靠性不足等问题突出,现阶段大多数轻瓦斯保护装置仅发出报警信号而不投跳闸。而近年来国内发生的多起变压器燃爆事故中,轻瓦斯保护均在事故前发出报警信号,这表明其性能具有一定的优越性。因此,对于变压器内部游离气体特性的研究具有重要意义。为分析油浸式变压器内部游离气体运动和汇聚规律,该文设计一个与实际变压器具有相似结构的模型试验箱体,开展典型绝缘缺陷在发展演化过程中的产气试验。基于ANSYS仿真软件,建立相应的气液两相流模型,对典型绝缘缺陷发展演化过程的不同阶段进行仿真分析。试验数据与仿真结果有良好的一致性,结果表明,随着绝缘缺陷的发展,游离气体从缺陷处转移到箱体内各类结构的表面;气体生成速率随着时间的推移而逐渐增加,在此期间气体呈现不同的运动模式并发生形态变化。基于相同理论模型对真型变压器内部气体行为进行仿真分析,得到其附着汇集规律。结果可为开发新型轻瓦斯保护装置提供有益参考。

应用于中继卫星通信系统的16QAM-TCM技术研究

网格编码调制技术可以在不改变信息传输频谱带宽的条件下,改善信噪比,减少发射功率,降低误码率,其实现的方法是分割星座图形成子集,逐步增大星座图中信号点之间的最小欧氏距离。本论文在项目组自研的中继卫星通信系统仿真平台上,仿真了8PSK与16QAM-TCM两种调制技术的解调性能,仿真曲线反映了误比特率需求与所需信噪比之间的关系。仿真结果表明:(1)在理想信道条件、I/Q(Inphase/Quadrature,同相/正交)幅相不平衡、幅频特性、群时延、相位噪声、功率放大器饱和点条件下,假设误比特率需求为1E-7,16QAM-TCM技术的信噪比需求与8PSK调制技术的信噪比需求相比,分别可节省8.85 dB、9.04 dB、8.45 dB、10.2 dB、8.5 dB、14.6 dB的信噪比;(2)在非线性信道条件下,当信噪比增大时,8PSK调制技术的误比特率在1E-3数量级附近波动,不再变化;(3)假设需求的误比特率为1E-7,16QAMTCM调制技术非线性信道信噪比仿真值与理想信道信噪比仿真值相比,损失了4.8 dB。

模拟仿真技术在10kV继电保护系统性能评估与优化中的应用

阐述通过建立系统模型,分析系统在故障检测、信号传输和操作响应中的问题。利用仿真工具进行性能测试,得到关键指标数据,提出优化措施。通过仿真实验,验证优化方案的有效性,并对优化后的系统进行综合评估,结果表明系统性能明显提升。

同步电动机自耦变降压起动动态仿真及分析

大型制氧空压机同步电动机是钢铁企业的关键设备之一,决定着高炉等重要工艺流程能源介质供给的可靠性。针对现场一台27000 kW制氧空压机同步电动机多次起动失败,并影响高炉生产的问题开展研究。介绍了采用ETAP软件开展电动机起动过程仿真的关键建模技术,主要包括:电动机等值模型、起动过程空压机负荷模型及自耦变模型,自耦变自身压降等值方法等。分析仿真结果后,提出了相应的起动策略,并对相应的继电保护整定值进行了优化,解决了困扰用户的空压机电动机起动失败难题。

基于截断正态分布的继电器多元维纳退化过程建模及可靠性评估

综合利用继电器多元性能参数退化数据建立多元性能退化模型,并开展继电器可靠性评估研究。选取多个继电器参数,考虑模型参数有界性的实际统计特性,建立改进的基于截断正态分布的多元维纳退化模型。针对所建立的模型,提出一种多阶段模型参数估计方法。以可靠度作为继电器可靠性的评价指标,提出基于蒙特卡洛仿真的可靠度近似计算方法,并通过实际案例验证所提方法的精确性和有效性。

一种基于OLSR协议的分布式多跳自组网技术研究

AdHoc网络是一种移动无线网络,具有网络结构组织灵活等特点。优化链路状态路由(OLSR)协议是专为适应无线自组织网络需求并对纯链路状态算法进行优化而形成的一种标准化先验式路由协议。针对组网终端在系统运行中网络拓扑临机改变导致网络中存在多跳寻址的需求,设计采用一种基于OLSR协议的分布式多跳自组网技术。该技术通过分布式网络感知综合考虑网内成员连通性及转发意愿,并根据多点中继节点(MPR)集选择算法分布式自适应选取网络内中继节点,为用户提供多跳寻址能力。通过OMNET++仿真平台验证了其可行性。

Northeast power system simulator(NEPSS)

1.IntroductionThe Northeast Power System is one of the four bulk powersystems in China,which covers the provinces of Liaoning,Jilin,Heilongjiang and a small part of Inner Mongolia.The total installedcapacity in 1990 was 21,300 MW and the peak demand was 13,600MW.The Control Center is in Shenyang.The dispatching automationsystem which is mainly composed of a dual computer system(2XVAX785)was installed and put into operation in 1988.The plan

环宽可调的滞环Simulink仿真模型

根据滞环的工作特性,利用Simulink 6.0构造了两种环宽可调的滞环模型。两种模型克服了Simulink模块库自带的滞环模块上下限值不可调的缺点,在应用中更为灵活,使用范围更广。为更好地利用Simulink软件进行环宽可调的滞环控制系统仿真研究提供了方便。仿真结果证明了两种模型算法的正确性,且有非常快的响应速度,可以在不同滞环宽度切换过程中平稳过渡。

基于VB平台的Simulink电力系统继电保护仿真

介绍了一种利用ActiveX技术将VB和Matlab仿真模型连接起来的方法。将VB界面友好和Matlab的Simulink工具箱强大的动态系统建模、仿真的优点充分发挥。克服了Simulink保密性不高,操作界面繁杂等缺点,提高了其实际应用的可行性。搭建了一个阻抗继电器的仿真实例,仿真结果验证了这种连接的正确性和直观性。