Research on uninterruptable power supply technology for auxiliary winding of electric locomotive while passing the neutral section

Purpose–Auxiliary power system is an indispensable part of the train;the auxiliary systems of both electric locomotives and EMUs mainly are powered by one of the two ways,which are either from auxiliary windings of traction transformers or from DC-link voltage of traction converters.Powered by DC-link voltage of traction converters,the auxiliary systems were maintained of uninterruptable power supply with energy from electric braking.Meanwhile,powered by traction transformers,the auxiliary systems were always out of power while passing the neutral section of power supply grid and control system is powered by battery at this time.Design/methodology/approach–Uninterrupted power supply of auxiliary power system powered by auxiliary winding of traction transformer was studied.Failure reasons why previous solutions cannot be realized are analyzed.An uninterruptable power supply scheme for the auxiliary systems powered by auxiliary windings of traction transformers is proposed in this paper.The validity of the proposed scheme is verified by simulation and experimental results and on-site operation of an upgraded HXD3C type locomotive.This scheme is attractive for upgrading practical locomotives with the auxiliary systems powered by auxiliary windings of traction transformers.Findings–This scheme regenerates braking power supplied to auxiliary windings of traction transformers while a locomotive runs in the neutral section of the power supply grid.Control objectives of uninterrupted power supply technology are proposed,which are no overvoltage,no overcurrent and uninterrupted power supply.Originality/value–The control strategies of the scheme ensure both overvoltage free and inrush current free when a locomotive enters or leaves the neutral section.Furthermore,this scheme is cost low by employing updated control strategy of software and add both the two current sensors and two connection wires of hardware.

Uninterrupted Progress

China remains committed to East Asian cooperationdespite recent frictions Contentious issues have not hindered progress in East Asian integration. And Chinese Premier Wen Jiabao’s attendance at the ASEAN summits in Hanoi showed integration would continue despite difficulties, said Chinese analysts.

机动通信系统UPS的漏电故障分析与处理

剖析机动通信系统中不间断电源(Uninterruptible Power Supply,UPS)的外壳漏电问题,提出相应的故障检测方法和解决方案。以广泛应用于机动通信系统的山特CASTLE 6G系列UPS为例,在分析其结构原理的基础上,通过实际案例验证了所提方法的可行性。此外,从选购、安装使用和维护保养3个方面出发,提出了有关UPS的安全使用建议,可为其他UPS用户提供参考。

Hydrophobic nanochannel self-assembled by amphipathic Janus particles confined in aqueous nano-space

Hydrophobic nanochannel plays a significant role in many physical, biological, and geological phenomena and ex- hibits impressive applications due to both its ubiquitous distribution and great ability to transport hydrophobic molecules, including various oils and gases. Based on theoretical modeling, we herein reveal that the amphipathic Janus nanoparticles have a large probability to self-assemble into uninterrupted hydrophobic nanochannels inside the aqueous nano-space, al- though there are large portions of the Janus nanoparticles to be hydrophilic. The key to this observation is the attractions between the hydrophobic regimes on neighboring amphipathic Janus particles through hydrophobic interaction in aqueous nano-space. More surprisingly, the permeation efficiency of hydrophobic molecules through the uninterrupted hydrophobic channel in Janus particles aggregate is even higher than that in the aggregate of hydrophobic particles. We note that the proposed amphipathic Janus particles can be transported to the appropriate positions by the water since the hydrophilic regimes still remain a strong particle-water interaction. We also note that most natural subsurface rocks are not completely hydrophobic or hydrophilic but have complex surfaces with inhomogeneous wetting property. Our work therefore provides a detailed molecular level understanding of the formation of underground strata as well as the new insight for constructing the artificial hydrophobic channels for various applications, such as the design of proppants to enhance the recovery of the unconventional oil/gas.

Location Prediction for Improved Human Safety at Complex Environments

In underground operation,primary consideration is safety.In recent decades,for minimizing accident and for preventing major economic losses and casualties,wireless sensors are used by various large mineral countries through early warning.The Improved DV-Hop Localization Algorithm(IDVHLA)is used in existing works for doing this.However,accurate anchor node detection is impossible in existing works with the malicious nodes presence,where there won’t be any accurate sharing of anchor node’s location information.In case of emergency situation,faster communication is a highly complex one.A technique calledModified Distance Vector Hop based Multipath Routing Protocol(MDVHMRP)is introduced in this proposed research work for resolving this.In this work,to detect anchor node position,a Modified Distance Vector Hop technique is introduced.This research work considers time taken and session time for computing neighbour node’s presence in addition to hop count values.Malicious nodes presence can be avoided by considering session time in neighbour node presence detection.The alert message are send by people in emergency crisis to sever in initial condition.Then Dynamic Source Routing(DSR)routing protocol is used for doing immediate route path selection.In case of route path failure,for ensuring uninterrupted communication and faster communication,this work introduces amulti path routing.Themodified distance vector hop technique is used for predicting anchor node location information and predicted information will be transmitted.In NS2 simulation environment,overall evaluation of this research work is carried out.When compared with available techniques,localization accuracy is enhanced by proposed technique as proven in experimental results.

论UPS的基础配置与维护保养

不间断供电系统UPS(Uninterruptible Power System)作为保护设备或者数据的最后一道屏障,越来越受到用户的关注与重视,尤其是精密仪器较多的场所或者大型数据交互中心,人们对UPS的需求越来越高,在数量、质量、性能等方面都有了具体的要求。因此UPS在其物理结构、系统配置、电池后备时间、维护保养以及故障的响应时间等方面都有了长足的进步与发展,以满足当前时代发展的需要。

核电厂交流不间断电源系统

本文以某核电作为参考,描述了核电厂交流不间断电源系统的结构组成和系统运行,及其主要设备——整流器、逆变器、蓄电池组、静态开关的功能特性,并从设计角度阐述了核电厂是如何确保交流不间断电源系统安全、可靠、稳定运行的。

A Temperature-Based Hysteresis Buck Converter for Dynamic Current Sharing

In this study, a temperature-based current sharing strategy rather than equal sharing for loads was applied to promote the reliability of uninterruptible power systems (UPS). According to the temperature of each power supply module in a UPS, it would be better to reduce the output current ratio for a hotter supply module in the UPS. In this design, we implemented our regulation circuits by the UMC 0.25-μm CMOS technology with an input range from 3 V to 4.2 V and the regulated output at 1.1 V. The rated output current was 100 mA for each phase. We also employed a current-mode error-correction circuit to improve the current sharing performance based on the averaged current of each phase at the same temperature. According to our simulation results, the current sharing error can be restricted within ± 5% for the supply modules at the same temperature in our system.

The Availability Improvement of Uninterruptible Power Supply by Stabilizing Node Application at Control Part

The UPS （uninterruptible power supplies） are essential power infrastructure components of systems designed for critical application, including data centers. High availability achievement is a very important factor related to UPS performance, consequently to proper critical application functionality. Generally, UPS have a limited input voltage window, referring to the nominal input voltage value. Goal of this paper is to prove larger voltage window, without affecting normal UPS operation. Larger window will result on less commutation, backup and normal mode reduction, and consequently duty time of batteries reduction, too. Thus, under these conditions, it is to be expected availability improvement. The stabilizing node model, applied at UPS＇s control part through this paper is presented. UPS＇s behavior with an implemented stabilizing node is observed at few sites. In order to analyze and conclude about UPS＇s performance under these technical conditions, simulation results are further presented.

High Temperature Superconducting Magnetic Energy Storage and Its Power Control Technology

High temperature superconducting （HTS） power inductor and its control technology have been studied and analyzed in the paper. Based on the results of simulations and practical experiments, a controlled release scheme has been proposed and verified for developing a practical HTS SMES prototype.

Remaining useful life prediction of lithium-ion battery based on auto-regression and particle filter

Purpose-With the rapid development and stable operated application of lithium-ion batteries used in uninterruptible power supply(UPS),the prediction of remaining useful life(RUL)for lithium-ion battery played an important role.More and more researchers paid more attentions on the reliability and safety for lithium-ion batteries based on prediction of RUL.The purpose of this paper is to predict the life of lithium-ion battery based on auto regression and particle filter method.Design/methodology/approach-In this paper,a simple and effective RUL prediction method based on the combination method of auto-regression(AR)time-series model and particle filter(PF)was proposed for lithiumion battery.The proposed method deformed the double-exponential empirical degradation model and reduced the number of parameters for such model to improve the efficiency of training.By using the PF algorithm to track the process of lithium-ion battery capacity decline and modified observations of the state space equations,the proposed PF t AR model fully considered the declined process of batteries to meet more accurate prediction of RUL.Findings-Experiments on CALCE dataset have fully compared the conventional PF algorithm and the AR t PF algorithm both on original exponential empirical degradation model and the deformed doubleexponential one.Experimental results have shown that the proposed PFtAR method improved the prediction accuracy,decreases the error rate and reduces the uncertainty ranges of RUL,which was more suitable for the deformed double-exponential empirical degradation model.Originality/value-In the running of UPS device based on lithium-ion battery,the proposed AR t PF combination algorithm will quickly,accurately and robustly predict the RUL of lithium-ion batteries,which had a strong application value in the stable operation of laboratory and other application scenarios.