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.

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.

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。

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.