UPS蓄电池放电时间和使用注意事项

本文简要介绍UPS原理及在维护UPS蓄电池过程中我们应该注意的事项,并着重介绍UPS蓄电池放电时的问题。     

简述UPS电源的测试条件及方法

介绍了UPS电源的测试环境条件、测试项目,并简述了负载能力的测试方法及步骤。该方法适用于新生产、使用中、和维修后的UPS电源的测试。     

一种基于电池恒功率放电模型和能耗预测的数据中心UPS蓄电池组放电时间估算方法

本文阐述了一种基于电池恒功率放电模型和能耗预测的数据中心UPS蓄电池组放电时间估算方法。     

广电行业蓄电池的维护及应用

近年来,随着广电安全播出要求的不断提高,UPS(不间断电源)以其体积小、效率高、无噪声振动、维护费用低、可靠性高等特点,越来越多地应用到机房交、直流供电系统中,特别是在影响较大的中心机房和传输干线机房,UPS蓄电池组已经成为保障网络安全播出的必备设施,作为UPS的核心,UPS蓄电池组的好坏直接决定UPS的整体性能,由于对"免维护"概念的误解,许多广电维护人员较少的关心在线蓄电池的健康状况,到供电异常或者事故发生后才意识到是后备蓄电池性能出问题,将详细介绍一下我台是如何解决UPS蓄电池组维护的难题和实际应用的。     

UPS蓄电池在广电领域中的应用及维护

随着广电行业的不断发展,对电源保护设备提出更高的要求,UPS(不间断电源)以其体积小、效率高、无噪声振动、维护费用低、可靠性高等特点,越来越多地应用到机房交、直流供电系统中,特别是在影响较大的中心机房和传输干线机房,UPS蓄电池组已经成为保障广电行业安全播出的必备设施,UPS电源包括两部分——UPS主机和蓄电池,它作为突然停电时用电设备的"救生员",是直播系统保障供电稳定和连续性的重要设备,因其主要机器智能化程度高,储能设备采用免维护蓄电池,使得在运行中往往忽略对该系统的维护与检修,其实维护的好坏,对电源的寿命和故障率有很大影响,描述UPS(不间断电源系统)的维护的要点,以及在广电系统中如何合理应用UPS供电系统。     

广播电视UPS电源可靠性与容错率的设计

该文简单说明了广播电视UPS电源及其设计依据,并对M(N+1)冗余、2N双母线冗余以及N+1并联冗余这些常见的UPS系统配置方案进行重点阐述。同时,对蓄电池容量的计算方法进行了全面分析,旨在提升广播电视UPS电源可靠性与容错率在设计方面提供参考与建议。     

蓄电池巡检仪、放电仪协议转换研究

蓄电池是变电站内直流系统的主要组成部分,是变电站内继保自动化等设备的后备电源。通过设计一个蓄电池单体电压数据转换装置,优化了蓄电池组的核对性放电试验接线,减少了试验时间。使用结果表明该转换装置安全高效,改进了蓄电池组的核容试验工作。     

基于PLC的动力蓄电池组性能测试系统设计

动力蓄电池组性能测试系统用于对动力电池的综合性能进行分析测试,该系统需要测试电池单体电压、温度、密度、充放电电流、容量、时间等参数.本文对电池组性能测试系统的充电系统、放电系统、上位机系统、检测方法进行了阐述,提出了基于PLC的动力蓄电池组性能测试系统设计方法.通过样机试验,证明了设计方法的可行性.     

电网直流电源系统继电保护探讨

文章对几类操作电源从可靠性、经济性、易维护性、适用范围等几方面进行了分析、比较。蓄电池组直流系统已成为电力企业各发电厂和变电所的标准配置,同时适用于大中型用户配电系统;而带UPS的交流电压操作电源是值得推荐的操作电源,其在中小型用户配电系统中能得到较好应用。     

UPS蓄电池筒述

简单介绍不间断供电电源——UPS,并以铅酸蓄电池为例详细介绍（UPS中）蓄电池的原理、参数、特性、使用及维护。     

锂离子电池负极材料TiS3 纳米片的制备和性能

先用直流(DC)电弧法制备TiH_1.924纳米粉作为前驱体,再用固-气相反应制备了片状结构的TiS₃纳米粉体。使用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、原子力显微镜(AFM)、拉曼光谱分析和性能测试等手段对其表征,研究了TiS₃纳米片的结构和将其用作负极的锂离子电池的性能。结果表明：TiS₃纳米片具有特殊的片状结构,其厚度约为35 nm。将TiS₃纳米片用作负极的锂离子电池具有良好的电化学性能,在500 mA/g电流密度下循环300圈后其容量仍保持在430 mAh/g。以5 A/g的大电流密度放电其比容量为240 mAh/g,电流密度恢复到100 mA/g其放电比容量稳定在500 mAh/g。TiS₃良好的倍率性能,源于其特殊的纳米片状结构。这种单层片状结构,能较好地适应电极材料在大电流密度多次放电/充电过程中产生的应变引起的体积变化,使其免于粉碎。     

AC Loss Analysis of a Model Coil for a 40 T Hybrid Magnet

A model coil for a 40 T hybrid magnet was designed and manufactured at the High Magnetic Field Laboratory of the Chinese Academy of Sciences (CHMFL); the model coil was wound with Nb₃Sn cable-in-conduit-conductors (CICC) and cooled with 4.5 K supercritical helium. The performance of the model coil was tested, and the performance tests included a DC charging test, AC losses test, temperature margin test, cyclic load test, and fast discharge test. The AC losses produced in the different operation scenarios of the tests were simulated and analyzed by a modified Gandalf code. The simulated AC losses will be presented and compared with the test results in this paper.     

A low-voltage Penning cell for vacuum measurement and vacuum technology

This paper presents new results on the performance of a special cold-cathode gauge. The use of an AC and DC voltage simultaneously as the power source makes it possible to ignite and sustain a discharge at a significantly lower voltage than normal over a wide pressure range (from 5 to 3×10⁻⁶ Pa). The Penning discharge voltage can be as low as 20 V at a pressure of 0.3 Pa and 300 V in high vacuum. For low values of pressure, the discharge current has a monotonously increasing dependence on the gas pressure. If a low RF voltage is applied to a high-voltage DC discharge, the discharge current increases in many times. These discharge properties can be used to improve the performance of devices that use the Penning and other magnetic discharges (total and partial pressure gauges, leak detectors, ion pumps, ion sources and hot plasma sources). A vacuum gauge of this type combines the best features of magnetic discharge and hot cathode ionization gauges.     

High-efficient three-phase on-line UPS by using T-source inverter with third harmonic injected maximum constant boost PWM control

This paper presents the analysis of three-phase on-line uninterruptible power supply (UPS) by employing T-source inverter (TSI) with third harmonic injected maximum constant boost PWM control and the results are compared with traditional UPS. Traditional UPS consists of step-up transformer or DC–DC booster along with voltage source inverter which decreases the efficiency and increases energy conversion cost. The proposed three-phase UPS using TSI has high-voltage boost capability through shoot-through zero state which is not present in traditional voltage source inverter (VSI) and current source inverter. This proposed UPS with TSI increases the efficiency with fewer components, reduces the harmonics, increases the voltage gain, and reduces the voltage stress. The performance of three-phase on-line UPS based on TSI is analyzed and evaluated in MATLAB/SIMULINK software and the results are compared with Z-source inverter-fed UPS and VSI-fed UPS. Experimental results are presented for the validation of the simulation and theoretical analysis.     

无声放电等离子体的光谱诊断

无声放电是一种非平衡态的、非稳定的和不均匀的放电 ,它被称作等离子体也是从时间平均的角度来考虑的。对这种非稳定的等离子体一直缺少一种有效的诊断手段。通过理论分析和实验提出用探针 光谱诊断技术测量无声放电等离子体的电子温度。气体放电中的光发射谱线是与等离子体的电子温度有关的。在直流放电的条件下 ,电子温度可通过朗谬尔探针的方法获得。如果能在同一放电系统中比较无声放电与直流放电的光谱数据 ,而直流放电的电子温度已知 ,则可以从比较当中得出无声放电电子温度的信息。本文通过这一方法给出了一个实验无声放电系统的电子温度与气体压强的关系。     

锂离子电池正极材料LiFePO_4在LiBC_2O_4F_2基电解液中的电化学性能

采用循环伏安、交流阻抗和充放电测试等研究了使用LiBC_2O_4F_2基电解液的LiFePO_4/Li电池(LiBC_2O_4 F_2电池)和使用LiPF_6基电解液的LiFePO_4/Li电池(LiPF_6电池)的电化学性能.结果表明,常温下LiBC_2O_4 F_2电池和LiPF_6电池的循环伏安曲线都只有1对对应于Fe~(2+)/Fe~(3+)的氧化还原峰,但是高温下LiPF_6电池的氧化还原峰分裂为多个氧化还原峰,而LiBC_2O_4F_2电池的氧化还原峰却与常温下类似,说明LiBC_2O_4F_2电池在高温下工作能保持较好的稳定性.常温下LiBC_2O_4F_2电池的初始放电容量比LiPF_6电池低,但其具有较高的容量保持率,而且在高温下具有比LiPF_6电池更高的放电容量和更优良的循环性能,如经过50次循环后,LiBC_2O_4F_2电池的容量保持率为92.5%,而LiPF_6电池的容量保持率为78.4%.交流阻抗图谱也表明,使用LiBC_2O_4F_2电池在高温下电池的界面电荷传输反应阻抗比室温下有所下降,说明其具有良好的高倍率性能和高温循环性能.     

尖晶石型LiMn_2O_4阴极材料电化学性能研究

利用柠檬酸络合法制备锂离子电池正极材料尖晶石型LiMn2 O4,利用X射线衍射、循环伏安、充放电测试、交流阻抗等手段对它进行了研究。发现活性物质在不同的电位下具有不同的电化学特征 ,电位处在平台区时与处在非平台区时相比 ,交流阻抗谱明显不同。电位处于非充放电平台区时 ,高频表现为锂离子电极材料中的固态扩散 ,在充放电平台区时 ,高频表现为电子到达活性物质的通道的阻抗。     

直流辉光和磁控增强放电等离子体的空间分辨发射光谱技术

光学发射光谱(OES)方法是等离子体诊断的有力工具之一,可以定量地给出等离子体的多种重要参数,如等离子体中的物种成分、粒子能态分布、激发温度、粒子相对密度等.本文介绍了一种用于电子回旋共振(ECR)微波等离子体磁控溅射靶附近的增强放电和直流辉光放电等离子体空间分辨诊断的发射光谱装置.其特点是光学收集系统的位置可以水平精细移动,因而可以对放电区域进行空间分辨发射光谱测量.作者利用这套装置对氩气的ECR微波等离子体和直流辉光放电等离子体进行诊断.在ECR微波等离子体的下游区内氩离子谱线的发射强度很弱,主要是高激发态原子的辐射.在磁共振增强放电区,离子谱线强度有所增加但仍比原子谱线弱,类似于直流辉光放电正柱区的光发射特性.     

Quantified non-destructive dispersion assessment via macrodispersion and AC/DC ratio analyses for hybrid polycarbonate/graphite nanoplatelet/carbon nanotube composites

New quantitative image analysis methods are presented for non-destructive characterization of nanocomposite macrodispersion. The first method employs spherical contact distribution functions allowing macrodispersion analysis for micrographs with thick sections or films previously requiring modification for analysis. Additionally, a promising quantitative approach utilizing the AC/DC conductivity ratio was demonstrated for the study of dispersion within hybrid polycarbonate/carbon nanotube/graphite nanoplatelet nanocomposites. For the first time, a mechanism for the correlation between the AC/DC ratio and nanofiller dispersion level is theorized. Furthermore, it is demonstrated that the AC/DC ratio method has the potential to be used with metrics for quality assurance and performance assessment of nanocomposites.     

Feedforward simple control technique for on-chip all-digital three-phase AC/DC power-MOSFET converter with least components

A novel simple control technique for on-chip all-digital three-phase alternating current to direct current (AC/DC) power-metal oxide semiconductor field-effect transistors (MOSFET) converter with least components, which is employed to obtain small current and DC output voltage ripples as well as excellent performance, and using a feedforward simple control method for DC output voltage regulation is proposed. The proposed all-digital feedforward controller has the features of low cost, simple control, fast response, independence of load parameters and the switching frequency, it has no need for compensation, and high stability characteristics; moreover, the proposed controller consists of three operation amplifiers and few digital logic gates that are directly applied to the three-phase converter. The power-MOSFETs are also known as power switches, whose control signals are derived from the proposed all-digital feedforward controller. Instead of thyristors or diodes, the application of power-MOSFETs can reduce the loss of AC/DC converter that is proper to the power supply system. The input stage of an AC/DC converter functions as a rectifier and the output stage is a low pass inductor capacitor (LC) filter. The input AC sources may originate from miniature three-phase AC generator or low-power three-phase DC/AC inverter. The maximum output loading current is 0.8 A and the maximum DC output ripple is less than 200 mV. The prototype of the proposed AC/DC converter has been fabricated with Taiwan Semiconductor Manufacturing Company (TSMC) 0.35 mum 2P4M complementary MOS (CMOS) processes. The total chip area is 2.333 1.960 mm². The proposed AC/DC converter is suitable for the following three power systems with the low power, DC/DC converter, low-dropout linear regulator and switch capacitor. Finally, the theoretical analysis is verified to be correct by simulations and experiments.