数据中心IT设备功率因数及其影响分析

数据中心IT设备功率因数在不断优化,采用有源PFC技术的高端IT设备,其输入功率因数已经接近1,对不间断电源供电系统产生了一些有利的影响.本文对IT设备功率因数变化及其产生的影响进行了深入分析,并提出了相应的合理化建议,可供UPS制造商、电源工程师和建设维护人员优化电源系统和相关产品.     

大功率UPS电源在广电机房中的技术应用及维护

利用UPS电源可以解决“电荒”造成的电源断电、电压突变、瞬间浪涌、频率漂移和高频干扰对用电设备造成的危害。本文就如何使用和维护UPS电源做扼要论述。     

大型数据机房UPS电源系统的可用性研究

为适应大型数据机房对UPS电源系统可用性提出的更高要求,笔者从“供电”角度对UPS电源系统的配置模式进行分析,从数据设备“用电”角度就如何进一步提高UPS可用性进行探讨,从而对UPS电源系统的设计和建设提出了一些合理化建议。     

不间断电源的选择与要求

为保证UPS用电设备的正常可靠运行，UPS电源设备的正确选择至关重要，文中提出了UPS有关参数的计算方法和注意事项。     

浅谈UPS的应用及日常维护

UPS电源可以解决电源断电、电压下陷、电源浪涌、减幅振荡、电源干扰、电源突波、交换瞬变以及谐波失真等会对前端设备造成危害的因素,电视节目的制作和有线电视前端系统的安全运行是安全播出的心脏至关重要,由于空调、热水器等设备的运转以及办公用电高峰重合时,经常发生大幅度的电压波动和严重杂波干扰.另外供电部门的停电维修及外电故障临时停电,会造成前端播出设备的损坏,每当前端停电用户的投诉电话便接踵而来意见很大,为确保有线电视网的安全运营和优质播出,前端必须使用UPS不间断电.     

UPS的原理与使用

介绍UPS电源的组成、工作原理、分类和特点，通过对各种类型UPS电源的比较，提出了一种新的直流型UPS供电方案，新的UPS电源系统具有良好的扩充性与分布性，允许多台小功率电源并联使用，共同向一台大容量负载供电，容易实现较高的功率因数校正，大大减小开关电源对电网的干扰污染，有利于实现净化电源的目标。最后讨论了UPS的负载问题，提出了UPS的一些使用、维护方法。     

基于Vicor HAM模块的PFC电源设计

为了提高用电设备对电能的利用效率,减少其对电网的谐波污染和电磁干扰,同时满足GJB151A-97标准中CE101项目对用电设备的电源谐波要求,研制了一台600 W的功率因数调整电源,即PFC电源。该电源采用美国Vicor公司的高增压谐波衰减（HAM）模块和V375系列DCDC模块,其中HAM模块用于控制电源输入电流,使其相位与输入电压相位保持一致,以减少谐波的产生,DCDC模块将HAM模块输出的直流高压转换为所需的直流电压输。经测试,该PFC电源达到了GJB151A-97中CE101项目对电源谐波抑制的标     

浅谈中心控制机房UPS电源的选择维护

首先对电网的供电特性以及UPS电源对用电设备的意义做了简要介绍,然后分别对不同UPS电源的工作特性、应用环境进行了分析和阐述,最后对UPS电源的维护工作的开展提出了相应的建议。     

机房中的动力源——UPS

电源是机房的主要动力来源，可靠稳定的电源是机房设备的支柱。UPS的主要功能是为机房内用电设备提供备用电源和改善电源质量。本文主要介绍UPS的类型、组成部分及其工作原理。     

关于UPS蓄电池的配置及维护的探讨

有1／3的计算机故障及70％的用电设备异常与电源有关，因此需要一种能够调节电压的变化、消除电气干扰、在市电故障时保证后备时间的中间设备，这就是UPS交流不问断电源。     

对UPS两项指标的探讨

本文阐述了UPS招标文件中输入电流谐波成份和输入功率因数两项指标的重要性,指出常用的双变换在线式UPS提高输入功率因数及降低输入电流谐波成份的解决方法.     

High-performance online UPS using three-leg-type converter

A high-performance single-phase online uninterruptible power supply (UPS) is proposed. The UPS is composed of a three-leg-type converter which operates as a battery charger and an inverter. The first leg is controlled to charge the battery, and the third leg is controlled to make the output voltage. The common leg is controlled in line frequency. The charger and the inverter are controlled independently. The charger has the capability of power-factor correction while charging a battery. The inverter regulates output voltage and limits output current under an impulsive load. The three-leg-type converter reduces the number of switching devices. As a result, the system has less power loss and a low-cost structure. In the determination of the charger voltage, the nominal voltage is derived using the feedback linearization concept and then a perturbed voltage is determined for the reactive power control. The disturbance of input voltage is detected using a fast sensing technique of the input voltage. Experimental results obtained with a 3-VA prototype show a normal efficiency of over 87% and an input power factor of over 99%.     

A new UPS scheme provides harmonic suppression and input powerfactor correction

A new parallel processing uninterruptible power supply (UPS) configuration is proposed in this paper. It provides active power line conditioning to minimize mains current distortion. This performance is superior to a conventional UPS. A prototype has been implemented and tested to verify its performance. The experimental results show that the input power factor of the proposed UPS is nearly unity, and the total harmonic distortion (THD) of the input current under nonlinear loading is only 3.618% for a mains voltage with THD of 1.633%     

高频整流器的输入功率因数及整流效率

为了验证各种高频整流器在UPS中应用的优越性,文中分析了几种不同类型高频整流器的输入功率因数及整流效率,发现不是所有的高频整流器的输入功率因数及整流效率都高,只有IGBTBoostSPWMPFC高频整流器的输入功率因数大于0．99,UPS效率大于94％,证明有些人所说的“任何容量的高频UPS的输入功率因数都可以做到0．99以上”是不准确的。     

A new UPS topology employing a PFC boost rectifier cascadedhigh-frequency tri-port converter

A new uninterruptible power supply (UPS) topology using the high-frequency tri-port UPS technique is proposed which presents the advantages of no-break power, low cost, input unity power factor, high power density, and high power conversion efficiency. Through the proposed circuit configuration, charging concept, and control strategy, the battery management is easily obtained by controlling the output voltage of the power-factor-correction (PFC) converter, which results in no additional power device being required for charging. The implementing circuit of the charging method is submitted to perform the two-stage charging, constant current charging, and constant voltage charging. The proposed technologies can be applied to the switching power supply with built-in UPS function featuring a low-cost solution for computer equipment, Finally, an experimental AC online UPS is built to verify the proposed concept, analysis, and control strategy     

采用小型汽油发电机对UPS供电探讨

在UPS供电系统中,市电中断时间较短时,蓄电池的直流电能经逆变器转换后给交流负载供电。但是,蓄电池的容量有限,不能长时间供电,为了保证市电长时间停电后设备能够正常工作,必须采用发电机来进一步支持UPS,共同组成UPS/发电机组的完整的不间断供电系统。对使用小型发电机为UPS供电出现的问题进行探讨,并提供实际的使用例子。     

采用小型汽油发电机对UPS供电探讨

在UPS供电系统中，市电中断时间较短时，蓄电池的直流电能经逆变器转换后给交流负载供电。但是，蓄电池的容量有限，不能长时间供电，为了保证市电长时间停电后设备能够正常工作，必须采用发电机来进一步支持UPS，共同组成UPS／发电机组的完整的不间断供电系统。对使用小型发电机为UPS供电出现的问题进行探讨，并提供实际的使用例子。     

A novel on-line UPS with universal filtering capabilities

A novel line-interactive uninterruptible power supply (UPS) is proposed that offers the characteristics of an “on-line” or “inverter-preferred” UPS (which incorporates a pulse-width modulation (PWM) rectifier) at a reduced cost. This new UPS is based on the combination of two full-bridge VSI converters: one in series with the input and the other in parallel with the load. The UPS acts as a line conditioner and output-voltage stabilizer in the presence of input power while charging the battery at a controlled rate. In case of loss of input power, the UPS can make a seamless transition to backup mode while supplying the load with a controlled sinusoidal voltage, drawing power from the battery. The series converter sees only a small percentage of the input voltage (typically, 10%-20%) while carrying the input current and therefore has a small kilovoltampere rating. The parallel converter supplies the load during blackout and hence determines the total kilovoltampere rating of the UPS. The reduced kilovoltampere rating of the series converter results in reduced system cost compared to conventional on-line systems without sacrificing any desirable characteristics. A laboratory version of the proposed UPS has been built to demonstrate the claimed capabilities, and both simulation and experimental results are included in the paper     

UPS电源在中波发射台的运用研究

不间断电源(Uninterruptible Power System,UPS)是当前广播发射台供电系统中不可缺少的组成部分,在处理电台突发断电状况、保护广播电视安全传输发射方面发挥着重要作用。随着UPS电源越来越多的配备到了中波发射台站中,如何管理和维护好UPS电源系统是一项重要工作。文中首先对UPS电源进行介绍,其次分析了UPS电源在717台的应用现状,最后对UPS电源的检修维护给出了相应的策略。     

Digital Control of Three-Phase Series-Parallel Uninterruptible Power Supply Systems

In this paper, a new digital deadbeat controller is designed, implemented, and applied to a three-phase series-parallel line-interactive uninterruptible power supply (UPS). This kind of UPS system provides input power factor correction, output voltage conditioning, and high efficiency. The objective of the controller is to achieve deadbeat dynamic response for the parallel and series converters. The proposed controller adjusts the current of the parallel converter and voltage of the series converter with two and four sampling periods, respectively. A reduced-parts topology is also introduced that has less number of power electronics components as well as switching functions. The power flow of the system in the presence of current and voltage harmonics is discussed. Simulation and experimental results are presented, which show the viability of the proposed controller for this topology.