新型馈电状态传感器的研究

文章根据《矿井安全监控新标准、新规程汇编》，首次研制了一种新型馈电状态传感器．这种传感器是以电容检测原理来监测电缆芯线对地电场状态的传感器．从而间接检测矿井电缆的馈电状态．与负载是否工作．电缆有无电流流过无关，只要电缆芯线带电，则输出馈电状态；反之，输出非馈电状态。这种馈电状态传感器具有结构简单、成本低、可靠性高、灵敏度高、易于维护、更换方便等优点。     

感应通信式矿用馈电状态传感器研究

为了进一步提高煤矿井下馈电状态传感器的性能,通过对煤矿井下特殊情况、馈电状态传感器的理论探索和现有应用的研究,根据《矿井安全监控新标准、新规程汇编》的要求[1],首次提出一种感应通信式馈电状态传感器,它是根据电压互感器原理和无线通信原理来实现的,从而间接检测矿井电缆的馈电状态,与负载是否工作,电缆有无电流流过无关,只要电缆芯线带电,则输出馈电状态;反之,输出非馈电状态.这种感应通信式馈电状态传感器具有灵敏度高、反映迅速、可靠性高以及维护量少等特点.     

智能馈电状态传感器的研究

介绍了一种适用于煤矿井下使用的智能馈电状态传感器。该传感器利用馈电电缆周围交替电场的不平衡原理检测电缆芯线对地的电场状态,从而间接检测出矿井电缆的馈电状态与电缆是否有电流无关。由单片机将馈电状态信号传输到监控系统。该传感器具有结构简单、成本低、安装方便以及信号传输距离远等特点。     

馈电状态传感器传感头结构形式研究

针对现有馈电状态传感器易受外界电磁场干扰而导致监控结果不准确以及无法监测AC3 300V及以上设备断电状态的问题,通过研究电容式非接触电场检测原理,设计出2种馈电状态传感器传感头结构形式,分别对铠装电缆和非铠装电缆电场变化进行检测,从而实现对被控设备的在线馈电监测,有效解决了现有矿用馈电状态传感器检测非铠装电缆时存在的易误报、抗干扰能力差、稳定性差的问题。     

电力电缆绝缘劣化判断的新方法

<正> 煤矿井下使用着大量的电力电缆,对安全可靠性的要求既高,占生产成本的比重也很大。加强对矿井电缆的劣化判断,掌握电缆的运行状况,对隐型故障早期发现,及时处理,防止事故扩大,避免供电中断,是很必要的。电力电缆是由导电芯线、接地芯线、     

铁路信号电缆断线故障在线监测与定位方法研究

铁路信号电缆是保证列车安全运营的重要组成部分,其故障严重影响列车的安全运营;由于其经多个分线盒接线柱连接的敷设特点,存在中间接头过多,致使传统的电缆故障检测方法应用受到了极大的限制;为此,通过在电缆中间分线盒的备用芯线对接线柱中接入固定阻值的电阻,将备用芯线对形成闭合回路网络,然后在线监测其电阻阻值,利用回路阻值的变化来反映电缆状态,并以在线监测备用芯线对代替在用芯线对,进而在不影响正常列控信号传输的情况下实现了信号电缆的故障在线监测;经实际测试,有效地解决了铁路信号电缆断线故障的在线监测及定位。     

基于LabVIEW的航空电缆故障检测系统

航空电缆不同于普通电缆,包含很多根芯线,要快速修复断开的电缆较为复杂,为了自动检测出断开电缆的芯线连接关系,文章利用LabVIEW的软件开发平台设计、研制了航空电缆故障检测系统;该系统可完成数据库查询、数据分析、结果显示和存储,利用系统中所建立的电缆资料数据库,结合检测电路等相应的硬件,系统即可自动检测出断开电缆的连接关系;应用该系统对某型飞机航空电缆进行了检测试验,结果表明,该系统可快速检测出损伤电缆的连接关系,检测结果准确、可靠.     

非接地式矿用馈电状态传感器设计

针对现有馈电状态传感器需要进行接地处理且易受干扰的问题,提出非接地式矿用馈电状态传感器设计方案。该传感器将信号探头包裹在负荷侧线缆上,并采用屏蔽层对极板进行防干扰处理,保证了极板和信号处理电路采用相同的参考地,能够在不接地的情况下准确检测出馈电状态。     

KDG15型远动开关的研制

文章根据煤矿井下瓦斯超限时需要对远距离(≥2 km)设备进行断电和闭锁控制、并要对被断电设备的断电状态进行确认的要求,介绍了一种防爆高压馈电检测型远动开关的设计。该远动开关不仅集远程断电和馈电状态监测2个功能于一体、检测馈电状态时不受铠装电缆屏蔽作用的影响,而且体积小、重量轻、免维护、使用方便。     

KDGl5型远动开关的研制

文章根据煤矿井下瓦斯超限时需要对远距离（≥2kin）设备进行断电和闭锁控制、并要对被断电设备的断电状态进行确认的要求,介绍了一种防爆高压馈电检测型远动开关的设计。该远动开关不仅集远程断电和馈电状态监测2个功能于一体、检测馈电状态时不受铠装电缆屏蔽作用的影响,而且体积小、重量轻、免维护、使用方便。     

变频式超声波发生器的高速锁相研究

构建了一种变频式超声波发生器,并对其中的高速锁相进行分析。通过换能器的电流反馈,采用基于嵌入式的数字式真有效值试探算法,超声波发生器锁相速度比传统速度提高数十倍,达到高速锁相的要求,满足了换能系统工作时的高速谐振需求。     

自动化配电网模型及故障恢复算法

传统配电网模型是以联络开关和分段开关为独立对象建立的,在大型的复杂的配电网系统中,这种模型的不足之处暴露无遗计算量庞大、效率低、并行性差。论文利用面向对象的方法,以母线及区域为主对象,以开关、连接线为辅对象,抽象出一种新的配电网模型,在此基础之上,使用Petri网描述它的状态变迁,最后给出了故障恢复算法。     

PowerPedia: changing energy usage with the help of a community-based smartphone application

When it comes to conserving electricity, it is crucial for users to know how much energy is consumed by individual appliances. However, the technical feedback provided by existing energy consumption feedback systems in the form of dry numbers and intangible units is not appropriate for most users. To address this shortcoming, we developed PowerPedia, a system that provides behavior-influencing feedback over and above pure consumption values. By integrating a community platform—a Wikipedia for electrical appliances—PowerPedia enables users to identify and compare the consumption of their domestic appliances with that of others. It thus helps users to better understand their electricity consumption and take effective action to save electricity.     

On the design of optimal output feedback control systems†

For a linear control system with quadratic performance index the optimal control takes a feedback form of all state variables. However, if there are some states which are not fed in the control system, it is impossible to obtain the optimal feedback control by using the usual mathematical optimization technique such as dynamic programming or the maximum principle.

This paper presents the optimal control of output feedback systems for a quadratic performance index by using a new parameter optimization technique.

Since the optimal feedback gains depend on the initial states in the output feedback control system, two cases where (1) the initial states are known, and (2) the statistical properties of initial states such as mean and covariance matrices are known, are considered here. Furthermore, the proposed method for optimal output feedback control is also applied to sampled-data systems.     

一种基于小波变换和ARIMA的短期电价混合预测模型

为在实时电价情况下预测未来24小时电价, 提出一种基于小波变换和差分自回归移动平均(ARIMA)的短期电价混合预测模型。该模型分别根据是否受到需求量影响使用ARIMA模型对多尺度小波变换分解后的时间序列进行预测。同时提出一种电价突变点发现和处理算法。使用澳大利亚新南威尔士州2012年真实数据验证表明, 相对ARIMA预测, 改进后的混合模型在不考虑需求量影响时预测精度更高; 电价突变点发现和处理算法能够准确处理电价异常点, 提高预测精度。     

A magnetoelectric energy harvester and management circuit for wireless sensor network

This paper presents an electromagnetic energy harvesting scheme by using a composite magnetoelectric (ME) transducer and a power management circuit. In the transducer, the vibrating wave induced from the magnetostrictive Terfenol-D plate in dynamic magnetic field is converged by using an ultrasonic horn. Consequently more vibrating energy can be converted into electricity by the piezoelectric element. A switching capacitor network for storing electricity is developed. The output of the transducer charges the storage capacitors in parallel until the voltage across the capacitors arrives at the threshold, and then the capacitors are automatically switched to being in series. More capacitors can be employed in the capacitor network to further raise the output voltage in discharging. For the weak magnetic field environment, an active magnetic generator and a magnetic coil antenna under ground are used for producing an ac magnetic field of 0.2–1 Oe at a distance of 25–50 m. In combination with the supply management circuit, the electromagnetic energy harvester with a rather weak power output (about 20 μW) under an ac magnetic field of 1 Oe can supply power for wireless sensor nodes with power consumption of 75 mW at a duration of 620 ms.     

Stabilization and destabilization of hybrid systems of stochastic differential equations

This paper aims to determine whether or not a stochastic feedback control can stabilize or destabilize a given nonlinear hybrid system. New methods are developed and sufficient conditions on the stability and instability for hybrid stochastic differential equations are provided. These results are then used to examine stochastic stabilization and destabilization.