中興ZXDU58 W121室外一體化通信電源機柜

中興ZXDU58 W121室外一體化通信電源機柜

概述

　　ZXDU58 W121 V4.0系列化產(chǎn)品是室外型120 A通信直流電源系統(tǒng)。默認輸出直流電壓-53.5 V，適用于220 V/380 V交流電網(wǎng)。該產(chǎn)品系列包含豐富的機柜系列和溫控系統(tǒng)組合，內(nèi)嵌120A電源插箱，構(gòu)成各種室外電源系統(tǒng)。

　　ZXDU58 W121 V4.0系列室外電源系統(tǒng)包含機柜和電源插箱兩部分組件構(gòu)成。　　

　　特點

• 寬電壓交流輸入范圍，80 V - 300 V，減少了電力不穩(wěn)定對設備的影響。
• 多種溫控設備可供選擇，適應各種場景的溫控需求
• 支持普效整流器與高效整流器混裝，節(jié)省能耗
• 提供三相和單項兩種可選交流輸入模式
• 提供一體化機柜和分體化機柜供用戶選擇

　　用戶體驗

•  選擇范圍寬
• 適應性強　中興ZXDU58 W121室外一體化通信電源機柜

Summary

The ZXDU58 W121 V4.0 series product is an outdoor 120 A communication DC power supply system. The default output DC voltage -53.5 V is suitable for 220 V/380 V AC power grid. The product series includes a rich combination of cabinet and temperature control systems, embedded in 120A power supply box, and forms a variety of outdoor power systems.

The ZXDU58 W121 V4.0 series outdoor power supply system consists of two components, a cabinet and a power supply box.

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Characteristic

The wide voltage AC input range, 80 V - 300 V, reduces the effect of power instability on the equipment.

A variety of temperature control devices can be selected to meet the temperature control needs of various scenes

Support mixed universal effect and high efficiency rectifier rectifier, energy saving

Two kinds of optional AC input modes for three phase and single item

Provide integrated cabinet and split cabinet for user selection

User experience

Wide range of selection

Adaptability

隨著近年來數(shù)據(jù)中心的大規(guī)模建設，傳統(tǒng)供電系統(tǒng)在大規(guī)模部署和運營中暴露的可靠性、維護性等問題日益突出，推動著用戶、設備商和方案設計公司合力進行供電系統(tǒng)的創(chuàng)新和優(yōu)化，供電系統(tǒng)的建設思路逐步從傳統(tǒng)上關注可靠性轉(zhuǎn)移到保障可用性上來。那么為何要建設高可用供電系統(tǒng)，如何建設高可用供電系統(tǒng)，本文對此做出了一些探討。

可用性綜合反映用戶的真實需求,可靠性是影響可用性的因素之一

可靠性通過可靠度來衡量,可靠度的定義為:“給定系統(tǒng)在規(guī)定的工作條件下和預知的時間內(nèi)持續(xù)完成規(guī)定功能的概率"。平均工作時間MTBF ( 又稱平均故障間隔時間) 是決定電源系統(tǒng)可靠度的重要指標，MTBF可通過定量定時的工業(yè)試驗或理論計算的方式獲得。可用性是指產(chǎn)品在任一隨機時刻需要開始和執(zhí)行時，處于可工作或可使用狀態(tài)的程度?？捎眯杂嬎愎绞牵?/p>

式中，MTBF(Mean Time Between Failures)是平均故障間隔時間，MTTR（Mean time to repair）是平均修復時間。

可靠性的高低代表了電源系統(tǒng)是否容易故障。但是從實際應用的角度來說，任何設備都不可能保證在生命周期內(nèi)不出故障，用戶希望的是設備盡量不出故障，即使故障了也不要因故障導致業(yè)務受影響；如果業(yè)務受到了影響，那么應盡快消除故障。相比之下可用性的定義相比可靠性范圍更加寬泛，對于可修復系統(tǒng)而言，它不僅涵蓋了設備是否容易出錯的問題，還涵蓋了設備是否容易從故障中恢復。很明顯可用性更加真實地反映了用戶的需求。

在UPS行業(yè)，通常用幾個“ 9"來代表系統(tǒng)可用性的高低。它是指一年內(nèi)，系統(tǒng)在線運行及可進行生產(chǎn)的時間比例。比如6個“9"(可用性可達到 99.9999%)，即每年可能存在的宕機時間少于 32 秒。UPS系統(tǒng)的目標是盡量提高 UPS 電源系統(tǒng)的可用性，減少來自市電的影響。

提升供電可用性的途徑

提高供電系統(tǒng)可靠性

從可用性計算公式可以看出，提高可靠性是提高可用性的一個重要途徑。提高供電設備可靠性分四個層次：

，設計標準級。在產(chǎn)品規(guī)劃設計階段，應充分考慮產(chǎn)品的可能應用環(huán)境，選定相應的設計標準。對產(chǎn)品使用時可能的電氣隔離、EMI/EMC、防雷、防浪涌、防噪干擾等電環(huán)境，防濕、防塵、防震、防腐等自然環(huán)境，及操作、維護、管理、搬運、安裝等的人環(huán)境有充分的評估，從而構(gòu)建產(chǎn)品合理的設計框架。

第二，器件級。在產(chǎn)品設計階段，嚴格篩選器件，配合電路設計，并反復模擬各種惡劣環(huán)境測試器件應力裕量，保障各類元器件的可靠運行。對于關鍵器件如電解電容，如果電路設計不夠優(yōu)化，紋波電流過大，芯溫過高，壽命將大大縮減，從而導致設備可靠性降低。散熱風扇也要選擇穩(wěn)定性好性能優(yōu)異的廠家提供，防止風扇故障導致功率模塊溫度上升，影響正常供電。

第三，部件級。部件的可靠性主要體現(xiàn)在它的穩(wěn)定性和冗余性，在保證部件故障率降至的前提下，關鍵部件采用冗余設計是提高部件級可用性的方法。

第四，方案級。通過優(yōu)化系統(tǒng)設計，使供電系統(tǒng)運行可靠穩(wěn)定，并且具備容錯能力，整個供電路徑無單點故障點。圖1展示了一個無單點故障的冗余系統(tǒng)架構(gòu)圖。該方案由兩套系統(tǒng)組成，在每套系統(tǒng)中，A4環(huán)節(jié)中興ZXDU58 W121室外一體化通信電源機柜做到輸入冗錯，A5環(huán)節(jié)做到雙回路互為備份，A6使用模塊化UPS或者并機， A7為單電源負載提供雙路保障，如果有條件A1和A2環(huán)節(jié)采用雙路市電輸入，單供電系統(tǒng)做到可靠冗余設計，然后方案采用2N容錯設計，基本做到無單點故障點和在線維護。

圖1 無單點故障的冗余系統(tǒng)架構(gòu)圖

提高UPS供電設備的可維護性

降低維護時間是提高可用性的另一重要途徑。模塊化設計可以有效改善易維護性，降低維護時間。UPS設備各個功能單元模塊化之后，故障之后只需更換上相應備件即可，大幅降低了維護的技術(shù)門檻，運維人員可自行更換維護。不但維護成本可有效降低，故障修復時間也可大幅縮短，從而將業(yè)務損失降到。另外，模塊化易于實現(xiàn)在線維護，即故障修復期間負載可以不斷電。如果需要斷電才能維護，就需要拉備用電源為負載供電，這樣維護非常復雜，而且維護時間很長。

提高UPS供電設備的易用性

易用性是供電設備“可用性"的升華，直接影響用戶的產(chǎn)品體驗。從用戶的角度看，需要從以下幾個方面改善：①易搬運、易安裝。這需要產(chǎn)品體積足夠小，重量足夠輕，并且是模塊化可分解，從而降低搬運和安裝的難度。此外UPS是否支持上下進線，是否支持并柜安裝等都將影響安裝的難度。②易擴容。數(shù)據(jù)中心一般都有未來的擴容計劃，以匹配未來的業(yè)務增長需要。而現(xiàn)網(wǎng)的UPS供電設備為了確?？煽啃酝ǔ９╇娐窂椒浅碗s，牽一發(fā)而動全身，擴容非常不便，即使條件滿足也有負載斷電的重大風險。這樣的供電現(xiàn)狀顯然是不易用的。如果能夠像通信電源一樣，功率模塊可以熱插拔，擴容只需采購功率模塊在線插進去，那么擴容的易用性就可大幅改善。③易管理。UPS設備要高度智能化，各個供電節(jié)點做到可視化管理，便攜化管理。比如，可以開發(fā)手機APP進行隨身監(jiān)控和管理。

UPS供電系統(tǒng)可用性發(fā)展的歷程

代UPS——動態(tài)UPS。其利用機械慣性儲能以及電動機、發(fā)電機的能量傳輸機制以提供短時間的不間斷供電，體積龐大、造價昂貴、噪聲巨大，猶如一個小型電廠。動態(tài)UPS的特征是占地面積較大，噪音大，不易維護和使用，接近一套工程設備。

第二代UPS——工頻機。相比于動態(tài)UPS，其可用性提升主要體現(xiàn)在以下幾個方面：，體積變小，搬運和安裝難度降低；第二，備電時間可以由后備電池決定，從動態(tài)UPS的秒級備電上升到小時級；第三，可以對較差電網(wǎng)優(yōu)化，如果一旦電網(wǎng)波動比較大，可以給后端設備提供相對穩(wěn)定的電力供應。但是，工頻UPS依然存在一些問題：，運輸與安裝問題。工頻機因為體積龐大無法通過門和內(nèi)置的升壓用變壓器重量太重無法使用電梯運輸?shù)?，導致安裝此類UPS經(jīng)常要打墻安裝、吊車運輸；第二，維護問題，UPS主機類似黑盒設計，有任何故障或者異常都只能依托原廠家維修，運維人員不敢直接打開操作，時間響應慢，對業(yè)務影響大。

第三代UPS——高頻機。高頻機的出現(xiàn)進一步提升了功率密度，體積減小了50%，從功能模塊上提升了維護性，縮短了MTTR時間，可在數(shù)小時內(nèi)完成修復。重量較工頻機進一步降低，有效提升了工程的可安裝性。同時，高頻機也大都采用了全數(shù)字化的高集成化設計，在維護性方面也有較大改進。THDi可以做到5%以下，明顯減少電網(wǎng)的諧波污染，效率也進一步提升到92-96%，體現(xiàn)出其節(jié)能優(yōu)勢。但是，對設備可用性的追求探索并未停止：單點故障是否可以排除？故障修復時間是否可以縮短至分鐘級？維護中興ZXDU58 W121室外一體化通信電源機柜技術(shù)門檻可否降低至可以自行維護？

第四代UPS——模塊化高頻UPS。高頻機技術(shù)的發(fā)展為UPS的模塊化架構(gòu)提供了技術(shù)可能，結(jié)合類似通信電源的模塊冗余技術(shù)的供電架構(gòu)，模塊化的高頻UPS得以實現(xiàn)。①可靠性大幅提高，常態(tài)工作的功率模塊、控制模塊實現(xiàn)全模塊化冗余，消除單點故障點。②經(jīng)濟效益顯著，模塊化技術(shù)使得UPS效率上了一個新臺階，同時采用了通信電源成熟的智能休眠功能，讓UPS系統(tǒng)始終處于效率點。③可維護性方面揭開了歷史嶄新的一頁，維護技術(shù)門檻也大幅下降。對于單模塊容量50KVA以下的小系統(tǒng)模塊化UPS，采用模塊熱插拔技術(shù)運維人員可以自行在線維護和擴容，故障修復時間和擴容時間也縮短至分鐘級，，對于單模塊容量200KVA以上的模塊化UPS，采用模塊隔離技術(shù)，雖然重量較重無法熱插拔，但運維人員可以自行在線分、合模塊來維護和查找故障，大幅度縮短修復時間，同時剩余模塊自行保證用戶的容量可用性。④在安裝、運輸上也體現(xiàn)出了模塊化的明顯優(yōu)勢——各單元模塊化可拆卸。模塊化高頻機UPS的功率密度比上一代產(chǎn)品更高，占地面積更小。據(jù)考證華為的小系統(tǒng)模塊化UPS可以做到單柜300KVA以上。

結(jié)語中興ZXDU58 W121室外一體化通信電源機柜

UPS供電設備的核心價值是保障高可用性，為用戶提供高品質(zhì)、易用的不間斷供電從而確保業(yè)務的穩(wěn)定運行，因此，對于數(shù)據(jù)中心UPS供電設備而言，我們需要轉(zhuǎn)換設計理念，從可靠性的點向可用性的面演進。而模塊化UPS相比傳統(tǒng)UPS在可靠性、易維護性、易用性等各個方面均有優(yōu)異的表現(xiàn)，可更有力地保障業(yè)務的連續(xù)性與穩(wěn)定運行，更契合用戶對于高可用供電的需求。

With the large-scale construction of the data center in recent years, the traditional exposure power supply system in large scale deployment and operational reliability, maintenance and other issues have become increasingly prominent, pushing users, equipment manufacturers and design companies ability to innovate and optimize the power supply system, power supply system construction ideas gradually focus from the traditional reliability to guarantee availability up. So why to build high availability power supply system and how to build high availability power supply system, this paper has made some discussion about this.

Availability reflects the real needs of the user, and reliability is one of the factors that affect availability.

Reliability is measured by reliability. The definition of reliability is "the probability that a given system can perform the specified function continuously under prescribed working conditions and predicted time". MTBF is also an important index to decide the reliability of power supply system. MTBF can be obtained by quantitative timing industrial test or theoretical calculation. Availability is the extent to which a product is in a working or usable state when it is required to start and execute at any random time. The formula of availability is:

In the formula, MTBF (Mean Time Between Failures) is an average fault interval time, and MTTR (Mean time to repair) is the average repair time.

中興ZXDU58 W121室外一體化通信電源機柜

The reliability of the power system is a representative of the power system is easy to fail. But from a practical perspective, any device can not guarantee full of trouble in the life cycle of the equipment is the user wants to try not to fail, even if the fault is not caused by malfunction affected business; if the business is affected, so the fault should be eliminated as soon as possible. In contrast, the definition of availability is broader than that of reliability. For repairable systems, it covers not only the problem of device's error, but also whether the device is easy to recover from failure. It is obvious that availability reflects the user's needs more truly.

In the UPS industry, a few "9" are usually used to represent the availability of the system. It refers to the proportion of the system running online and the time that can be produced in one year. For example, the 6 "9" (availability can reach 99.9999%), namely every possible downtime is less than 32 seconds. The goal of the UPS system is to improve the availability of the UPS power system as far as possible and reduce the impact of the power from the city.

Ways to improve the availability of power supply

Improving the reliability of power supply system

From the calculation formula of availability, it can be seen that improving reliability is an important way to improve availability. Improving the reliability of power supply equipment is divided into four levels:

First, design the standard level. In the stage of product planning and design, the possible application environment of the product should be fully considered and the corresponding design standards should be selected. The electrical isolation, the use of the product EMI/EMC, lightning protection, anti surge, anti noise and electrical environment, moisture resistance, dustproof, shockproof, anti corrosion and natural environment, operation, maintenance, management, transportation and installation of the environment have been adequately assessed, so as to construct a reasonable framework for the design of products.

Second, device level. In the stage of product design, we must strictly select the device and cooperate with the best circuit design, and repeatedly simulate all kinds of harsh environments to test the device's stress margin, so as to ensure the reliable operation of all kinds of components. For key devices such as electrolytic capacitors, if the circuit design is not optimized enough, the ripple current is too large and the core temperature is too high, and the life will be greatly reduced, resulting in the reduction of device reliability. The fan also should choose the manufacturers with good stability and good performance to prevent the fan fault from rising the power module temperature and affecting the normal power supply.

Third, component level. The reliability of components is mainly reflected in its stability and redundancy. Under the premise of minimizing the failure rate of components, the most effective way to improve the availability of components is redundancy design of key components.

中興ZXDU58 W121室外一體化通信電源機柜

Fourth, program level. By optimizing the system design, the power supply system is reliable and stable, and has the ability of fault tolerance. There is no single point of failure in the whole power supply path. Figure 1 shows a diagram of a redundant system architecture without a single point of failure. The scheme consists of two systems, in each system, A4 link to achieve input redundancy, A5 link to achieve double loop mutual backup, A6 or UPS and the use of modular machine, A7 provides dual protection for single power load, if the conditions of A1 and A2 link using dual mains input redundancy the design to achieve a single power supply system, and then the scheme uses 2N fault tolerant design, basically no single point of failure and online mainten中興ZXDU58 W121室外一體化通信電源機柜ance.

Figure 1 redundant system architecture diagram without single point failure

Improve the maintainability of UPS power supply equipment

Reducing maintenance time is another important way to improve availability. Modular design can effectively improve the maintainability and reduce the maintenance time. After the modularization of each functional unit of UPS device, the replacement of the corresponding spare parts can only greatly reduce the technical threshold for maintenance, and the operation and maintenance personnel can replace and maintain themselves. Not only the maintenance cost can be effectively reduced, but the time of fault repair can be reduced greatly, so the business loss is reduced to a minimum. In addition, the modularization is easy to maintain online, that is, the load can not be cut off during the fault repair. If power is needed to maintain, it is necessary to pull the backup power supply to the load, which is very complicated and has a long maintenance time.

Improve the usability of UPS power supply equipment

Ease of use is the sublimation of the "availability" of power supply equipment, which directly affects the user's product experience. From the point of view of the user, it is necessary to improve the following aspects: 1. Easy to handle and easy to install. This requires that the product is small enough, the weight is light enough, and it is a mold.

近年來，隨著互聯(lián)網(wǎng)、云計算、移動互聯(lián)網(wǎng)和物聯(lián)網(wǎng)等技術(shù)的快速發(fā)展，數(shù)據(jù)中心系統(tǒng)規(guī)模不斷增大，重要性越來越高，其對系統(tǒng)彈性、可用性、運營效率、可運維性等提出了更高的要求。作為數(shù)據(jù)中心供配電系統(tǒng)的關鍵組成部分，UPS無疑需要匹配這種要求。在此背景下，UPS模塊化已經(jīng)成為業(yè)界的共識。與傳統(tǒng)塔式機相比較，模塊化UPS具有以下優(yōu)勢：

1）投資有效性：隨需擴容，節(jié)省初期投資；

2）模塊冗余高可靠性：避免出現(xiàn)重大斷電事故；

3）易維護性：在線熱插拔，維護簡單快速，無須轉(zhuǎn)旁路；

4）節(jié)能環(huán)保性：對電網(wǎng)污染小，高效率及模塊休眠等技術(shù)減少能源浪費。

正因為具有如此眾多的優(yōu)點，目前大多數(shù)UPS廠商都已發(fā)布模塊化UPS，越來越多的用戶已經(jīng)或正在考慮使用模塊化UPS建設新數(shù)據(jù)中心。但現(xiàn)今市場上的模塊化UPS所采用的技術(shù)不盡相同，客戶在選用過程中有一定的困惑，本文將基于筆者的應用實踐與理解對兩種主流架構(gòu)的模塊化UPS進行剖析，希望能給各位讀者一些幫助及啟發(fā)。

2. 模塊化UPS的兩種典型架構(gòu)

1)分布式架構(gòu)

圖1中展示了分布式模塊化UPS的系統(tǒng)架構(gòu)。

中興ZXDU58 W121室外一體化通信電源機柜

 
       圖1 分布式結(jié)構(gòu)的模塊化UPS架構(gòu)

分布式是早期模塊化UPS經(jīng)常使用的一種架構(gòu)。此類模塊化UPS系統(tǒng)層面上等價于數(shù)立的UPS直接并聯(lián)，其功率模塊利用小型UPS改造而成，可自主獨立工作，其特點是：①除整流、逆變的控制外，均流與邏輯切換也由內(nèi)部控制單元控制；②內(nèi)置容量與功率模塊容量一致的靜態(tài)旁路，在旁路模式時，由每個模塊內(nèi)的靜態(tài)旁路共同承擔負載。

2)分布+集中式架構(gòu)

與之相對應，圖2展示了另一類架構(gòu)的模塊化UPS。

中興ZXDU58 W121室外一體化通信電源機柜

 圖2 分布+集中式結(jié)構(gòu)模塊化UPS架構(gòu)

分布+集中式結(jié)構(gòu)的模塊化UPS設備所有的功率模塊內(nèi)置控制單元用于本模塊的整流器與逆變器控制，而將整個系統(tǒng)的均流及邏輯切換等功能從模塊內(nèi)部控制單元中提取出來，由一個集中的控制模塊控制。為了消除可能引入的單點故障，該控制模塊及相應通訊總線均進行1+1冗余。當一個控制單元出現(xiàn)故障時，整個UPS系統(tǒng)中功率模塊可由另一處于熱備狀態(tài)的控制單元無縫接管系統(tǒng)控制，保障系統(tǒng)不間斷運行。同時，功率模塊內(nèi)不再內(nèi)置靜態(tài)旁路，系統(tǒng)配置一個靜態(tài)旁路模塊，其容量即為系統(tǒng)容量

3. 分散控制與分布+集中控制邏輯模式對比

分布式架構(gòu)的模塊化UPS采用分散控制邏輯模式，系統(tǒng)中每個模塊都含有一個完整獨立的控制單元，系統(tǒng)的主控模塊會通過一定的邏輯規(guī)則從系統(tǒng)內(nèi)所有模塊中選出，其余模塊作為從控模塊聽從主控模塊調(diào)度。當UPS系統(tǒng)中的一個從控模塊出現(xiàn)故障時其余模塊仍正常工作，當主控模塊出現(xiàn)故障時可通過一定的競爭規(guī)則來使得另一個模塊作為主控模塊，保障系統(tǒng)繼續(xù)正常工作。

分散控制邏輯模式的優(yōu)點在于每個控制單元都可以完成對系統(tǒng)獨立控制的工作，故不存在這方面的單點故障點。但缺點也很明顯，首先因為主控模塊既要處理本身的信號，又要協(xié)調(diào)各模塊之間的信號，所以控制邏輯比較復雜，軟件邏輯可靠性不高。其次各主控模塊故障后，會在剩余模塊中競爭產(chǎn)生一個模塊作為主控模塊，該過程中也容易發(fā)生競爭失敗導致系統(tǒng)故障。

分布+集中式架構(gòu)的模塊化UPS功率模塊內(nèi)整流、逆變的控制是分布的，而均流邏輯等控制則是集中控制模式，即采用獨立集中的控制模塊（如圖2中控制模塊）來檢測市電的頻率和相位，然后向每個模塊發(fā)出同步信號，各個功率模塊接受到此同步信號后通過自身的控制環(huán)輸出相應頻率相位的正弦波。當市電丟失時，集中控制模塊會自激產(chǎn)生同步信號發(fā)送給各個UPS模塊來保證各單元的輸出同頻同相。同時在均流的控制實現(xiàn)形式方面，集中式架構(gòu)的模塊化UPS依靠控制模塊來檢測整個系統(tǒng)的負載電流，然后除以系統(tǒng)模塊數(shù)量來作為各個UPS模塊的均流參考值，進而與各模塊輸出電流比較后求出偏差值來不斷調(diào)整各模塊的輸出電流，以保證系統(tǒng)內(nèi)模塊間良好的均流度。分布+集中控制邏輯模式的優(yōu)點在于采用獨立的均流與邏輯控制單元，均流度更好，且控制邏輯層級清晰，各功率模塊之間不存在競爭關系，軟件邏輯可靠性較高。為了保證集中控制單元的可靠性，避免單點故障，一般采用該架構(gòu)的UPS控制單元及通訊線路均會做1+1備份。1+1熱備份是的備份方式，其可靠性在各類系統(tǒng)長期運行實踐中已得到驗證。
綜合來說，集中式冗余架構(gòu)具有的優(yōu)勢是明顯的。

4. 集中旁路與分散旁路對比

正如本文中兩種架構(gòu)圖所示，目前大容量模塊化UPS系統(tǒng)的旁路控制技術(shù)主要有兩種模式：1、系統(tǒng)集中旁路模式（UPS系統(tǒng)內(nèi)只有一套旁路系統(tǒng)，如圖2所示）；2、系統(tǒng)分散旁路模式（UPS系統(tǒng)內(nèi)每個功率模塊都有一套旁路系統(tǒng)，如圖1所示）。集中旁路系統(tǒng)具有過載能力強，可靠性高的優(yōu)點，而分散旁路具有可擴容，成本低的優(yōu)點，但可能存在一定的可靠性風險。

對于分散旁路模式，表面上看因分散布置，在UPS模塊冗余時類似于冗余設計，一處旁路故障，其它旁路仍可工作。實際上此種分散與冗余有本質(zhì)不同。旁路的主要器件為SCR。因為器件的離散性較大，系統(tǒng)工作在旁路模式時，各個旁路基本不可能處于均流狀態(tài)；而為了保持旁路輸出的電壓波形完整，在旁路模式時不會進行開關動作，難以電流進行控制，僅依賴自然均流不均流度很難控制在25%以內(nèi)，電流大的模塊很可能因旁路過載而關機，影響系統(tǒng)供電連續(xù)性。

除了穩(wěn)態(tài)的均流問題，在瞬態(tài)時分散旁路系統(tǒng)也具有一定的風險。在系統(tǒng)控制器發(fā)送切換旁路模式的信號之后，因為信號傳輸路徑、模塊控制器響應速度、器件一致性等各方面原因，各個旁路很難同步切換，而先切換導通的SCR將承擔大部分負載甚至所有負載，極易導致該SCR失效。

靜態(tài)旁路是主路模式的冗余，作用非常重要。而分散旁路的設計方式大大降低了旁路的可靠性。實際上，在傳統(tǒng)塔式UPS應用中當并機數(shù)超過四臺時，一般為了避免旁路不均流問題，都需要采用集中靜態(tài)旁路系統(tǒng)。因為旁路系統(tǒng)的限制，采用分散旁路系統(tǒng)的UPS很難具有較好可擴展性。

5. 總結(jié)

如上所述，模塊化UPS因其高可靠、易維護、易擴容等優(yōu)點，大大地節(jié)省了客戶運營維護成本，為業(yè)務的長期穩(wěn)定運行提供了保障。兩種典型架構(gòu)的模塊化UPS都能提供較好的維護性與擴容能力，比起傳統(tǒng)UPS的可用性大幅提升。但從技術(shù)角度分析，集中式結(jié)構(gòu)的模塊化UPS具有更高的安全性，更優(yōu)異的可靠性。

In recent years, with the rapid development of technology such as Internet, cloud computing, Internet and Internet of things, the size of data center system is increasing, and its importance is higher and higher. It puts forward higher requirements for system flexibility, availability, operation efficiency and operation and maintenance. As a key component of a data center for distribution systems, UPS is undoubtedly required to match this requirement. In this context, UPS modularization has become a consensus in the industry. Compared with the traditional tower machine, the modular UPS has the following advant中興ZXDU58 W121室外一體化通信電源機柜ages:

1) investment effectiveness: to expａnd the capacity with the need to save the initial investment;

2) high reliability of module redundancy: avoid major power failure;

3) easy maintenance: online hot plug, simple and fast maintenance, no bypass;

4) energy conservation and environmental protection: small pollution of the power grid, high efficiency and module dormancy technology to reduce energy waste.

Because of so many advantages, most UPS manufacturers have released modular UPS at present. More and more users are considering the use of modular UPS to build new data centers. But the UPS module on the market today the technology is not the same, customers have a certain confusion in the selection process, the practice and understanding of the author based on the modularization of the two mainstream architectures of UPS are analyzed, the hope can give you some inspiration and help readers.

The two typical architecture of 2. modularized UPS

1) distributed architecture

The system architecture of distributed modular UPS is shown in Figure 1.

中興ZXDU58 W121室外一體化通信電源機柜

Graph 1 modular UPS architecture of distributed structure

Distributed is an architecture that is often used by early modular UPS. This kind of modular equivalent UPS system level on the number of independent UPS directly parallel, the power module and the use of small UPS transformation, can work independently, its characteristics are: the control of rectifier, inverter in addition, uniform flow and also by the internal logic switching control unit control; the internal capacity and static bypass the power module capacity is consistent, in bypass mode, the static bypass within each module shared load.

2) distributed + centralized architecture

In contrast, figure 2 shows the modularized UPS of another type of architecture.

Graph 2 distribution + centralized structure modularized UPS architecture

分布+集中式結(jié)構(gòu)的模塊化UPS設備所有的功率模塊內(nèi)置控制單元用于本模塊的整流器與逆變器控制，而將整個系統(tǒng)的均流及邏輯切換等功能從模塊內(nèi)部控制單元中提取出來，由一個集中的控制模塊控制。 In order to eliminate the single point of fault that may be introduced, the control module and the corresponding communication bus all carry out 1+1 redundancy. When a control unit fails, the power module in the whole UPS system can be controlled by another control unit which is in hot standby state, which ensures seamless operation of the system. At the same time, the static bypass is not built in the power module, and the system is equipped with a static bypass module, which is the capacity of the system.

3. distribution control and distribution + centralized control logic model comparison

UPS modular distributed architecture with distributed control logic model, each module of the system contains a complete and independent control unit, main control module of the system will be selected from the system in all modules through certain logic rules, the other from the control module to the module as the main control module scheduling. When one of the UPS modules fails, the other modules still work normally. When the main control module fails, a certain rule of competition can be used to make the other module as the main control module, so that the system will continue to work normally.

The advantage of the decentralized control logic mode is that each control unit can complete the work of independent control of the system, so there is no single point of fault in this respect. But the disadvantages are also obvious. First, because the main control module not only processes its own signal, but also coordinates the signals between modules, so the control logic is more complex and the software logic reliability is not high. Secondly, after each main control module fails, a module will be generated in the remaining modules as the main control module, which is also prone to competition failure, resulting in system failure.

Control + distribution centralized architecture modular UPS power module, inverter rectifier is distributed, and the flow control logic is centralized control mode, which adopts the independent centralized control module (Figure 2 control module) to the frequency and phase detection of the power, then sends a synchronization signal to each module. Each power module receive the synchronous signal through its control loop output the corresponding frequency sine wave phase. When the electricity is lost, the centralized control module will generate the synchronization signal to each UPS module to ensure the same phase of the output of each unit. At the same time form in controlling flow, UPS modular centralized architecture relies on control module to detect the load current of the whole system, and then divided by the number of modules of the system as a flow of reference value of each UPS module, and then compared with the output current of each module after the obtained partial difference to continuously adjust the output current of each module. In order to ensure the system modules are good mobility. The advantage of the distributed + centralized control logic mode is that the independent flow and logic control unit is adopted. The flow rate is better, and the control logic level is clear. There is no competition relationship among the power modules, and the software logic reliability is relatively high. In order to ensure the reliability of the centralized control unit and avoid a single point of fault, the UPS control unit and the communication line of this architecture will do 1+1 backup. 1+1 hot backup is the most commonly used backup method, and its reliability has been verified in the long run practice of various systems.

Integrated

目前UPS產(chǎn)品在行業(yè)應用已有五十余年的歷史，其為保障關鍵設備和業(yè)務的不間斷運行做出了的貢獻。隨著信息化建設的不斷推進，需要UPS保護的場景越來越多，其作用愈發(fā)重要。當前市場上存在工頻機、高頻塔式機、高頻模塊化UPS三類產(chǎn)品，其利弊優(yōu)劣眾說紛紜，令用戶感到十分困惑。本文旨在通過闡述UPS的發(fā)展歷史及對比各類UPS的優(yōu)劣勢，幫助用戶識別UPS產(chǎn)品發(fā)展的趨勢所在。

一、從工頻機UPS到高頻塔式機UPS的發(fā)展

工頻機結(jié)構(gòu)UPS技術(shù)出現(xiàn)在上世紀70年代，因其整流工作頻率與電網(wǎng)頻率一致而得名。受制于當時半導體技術(shù)發(fā)展，逆變器中IGBT器件耐壓只能做到600V，故母線電壓受限，逆變器輸出電壓不能做到380V；而且工頻機逆變器是全橋電路，輸出為三相火線，無法滿足單相IT負載和三相四線制負載的需求，必須進行Δ-Y轉(zhuǎn)換。為解決這些問題，廠家在工頻機逆變器輸出端加入了變壓器用于升壓和產(chǎn)生中線，以使輸出電壓滿足負載的要求，這便是工頻機內(nèi)置變壓器的真實目的。圖-1所示為工頻機的典型拓撲。

中興ZXDU58 W121室外一體化通信電源機柜

圖-1 工頻機典型拓撲

而到上世紀90年代，第三代溝槽型IGBT面世，其耐壓能力提升至1200V，促使了UPS技術(shù)的革新。通過整流側(cè)高頻升壓電路將母線電壓提升至700V左右，逆變器輸出電壓可以做到380V，輸出變壓器得以取消。而這種整流逆變電路都工作在高頻（幾kHz以上）且沒有輸出變壓器的UPS就被稱為高頻UPS。圖-2所示為一典型的高頻機拓撲。

圖-2 高頻機典型拓撲中興ZXDU58 W121室外一體化通信電源機柜

二、高頻UPS與工頻UPS的對比

1.工頻機輸入功率因數(shù)低、諧波高

工頻機UPS采用可控硅半控整流，6脈沖整流UPS輸入功率因數(shù)低于0.7，諧波高達30%；12脈沖整流UPS輸入功率因數(shù)僅為0.8，諧波高達15%，即使加上諧波處理措施，功率因數(shù)也只能改善至0.95。相比之下，高頻機采用IGBT-PFC全控整流，輸入功率因數(shù)業(yè)界均可做到0.99，諧波電流小于3%。嚴重的諧波污染不僅可能干擾其他設備無法工作、使控制與保護器件誤動作外，而且直接導致投資大幅增加：客戶需要購買額外的諧波處理設備降低諧波；如果前端接柴油發(fā)電機備電，發(fā)電機的容量要配置為UPS容量的2-3倍，同時前級配電器件、線纜等均需要提升20%左右，而高頻機只需前端發(fā)電機容量配置為UPS容量的1.2-1.5倍即可，配電容量和UPS容量保持一致或略高。

2.工頻機功耗大

有三個因素導致工頻UPS效率低于高頻UPS。一是工頻UPS整流為降壓拓撲，器件工作電流大，無論是內(nèi)部線路無論是線性損耗還是平方損耗都比高頻機高；二是因輸出需要升壓的原因工頻機比高頻機多內(nèi)置一個輸出變壓器，致使工頻機效率下降2%-3%左右；三是在實際應用中，為了提高輸入功率因數(shù)至0.95以上，并降低其注入電網(wǎng)的諧波污染，工頻機還要外置一個5次或11次諧波濾波器，效率將再次下降2%-3%。據(jù)英國某運營商與西班牙某運營商現(xiàn)網(wǎng)運行統(tǒng)計數(shù)據(jù)，工頻UPS的效率一般在85%左右，相比高頻92%左右的運行效率和模塊化96%左右的運行效率，導致大量的能量損失。以400kW負載為例，工頻機將比高頻機年多耗電41萬度，比模塊化年多耗電近58萬度。除此之外，工頻UPS還有高諧波、低功率因數(shù)等導致配電線纜損耗增大等問題。

3.工頻機體積大、重量重

因為工頻機采用低頻器件且配置輸出變壓器，致使UPS體積重量大大增加。以某品牌400kVA工頻機和高頻機對比，工頻機重量是高頻機的2.2倍，體積是高頻機的1.5倍，在實際運輸中可能存在機房門或者走道偏小、電梯載重不夠、樓層承重不足等問題，有些情況下甚至需要用吊車裝卸，然后破墻而入來安裝工頻UPS，大大增加了運輸時間及成本。

4.工頻機相比高頻機在可靠性方面并無優(yōu)勢

工頻機和高頻機的主要差異體現(xiàn)在整流器和變壓器上。工頻機整流器采用SCR器件，電壓應力小，電流應力大，高頻機主要采用IGBT器件，電流應力小，電壓應力大。SCR與IGBT目前均為成熟器件，只要應用得當，可靠性并不會有差異。事實上，工頻機的逆變部分也是使用IGBT，并沒有因此而降低工頻機的可靠性，也沒有證據(jù)證明逆變器是工頻機的薄弱環(huán)節(jié)。從拓撲上講，工頻機用的是相控整流+全橋逆變，高頻機一般采用高頻整流+半橋逆變。這些拓撲均為電力電子技術(shù)上非常常用的拓撲，并不存在誰原理上更可靠的問題，其可靠度取決于設計的水平。

而對于變壓器，業(yè)界經(jīng)?？梢月牭狡浜芏嗨^的優(yōu)點，比如抗沖擊能力強、降低零地電壓等，然而真的是這樣嗎？

，過載能力強，抗負載沖擊能力強。過載能力是IEC62040-3中要求標稱的關鍵指標之一，其強弱可通過實際數(shù)據(jù)來衡量。表-1所示為同一廠商的工頻機與高頻機過載能力，由表-1可知，兩類機型過載能力并沒有區(qū)別。

表-1 某廠商工頻機與高頻機過載能力對比

輸出變壓器并不會增強工頻機的抗沖擊能力，中興ZXDU58 W121室外一體化通信電源機柜對于變壓器可以增強抗沖擊能力的想象來源于變壓器的電感特性，電感平滑電流的能力在負載電流激增時可以平滑電流波形延緩電流沖擊。但實際上電感平滑電流的能力與其本身感量成正比。工頻機輸出變壓器變比小，變壓器輸出繞組的勵磁電感也不會太大，在大電流沖擊下極易飽和，很難對逆變器的沖擊有明顯的緩沖作用。而按照傳統(tǒng)變壓器傳遞能量的特點與磁性器件原理分析，當后級負載也就是變壓器輸出側(cè)出現(xiàn)能量沖擊時，在變壓器能量傳遞能力達到飽和上限之前，后端的尖峰勵磁電流會直接反射到前端對UPS的IGBT產(chǎn)生沖擊，并且由于變壓器的變比問題前端所受到的沖擊電流會比輸出端更大，同時造成的損害也更為嚴重。而且，工頻系統(tǒng)由于變壓器的磁滯特性，難以實時監(jiān)測后級動態(tài)響應。當變壓器后端出現(xiàn)突變并反饋到前級時，系統(tǒng)采取相關動作較無變壓器的高頻機來說會延遲幾十甚至幾百個ms，此時流過IGBT的沖擊電流已經(jīng)足夠損壞UPS甚至引發(fā)火災。

第二，在逆變器IGBT管直通故障時隔斷直流危險電壓。工頻機變壓器確實可以避免直流傳遞至副邊，但高頻機通過快速檢測與保護措施一樣可以避免直流危險電壓對負載造成危害。當高頻機逆變某IGBT出現(xiàn)直通故障時，UPS控制器可立即檢測輸出電流異常，并通過整流單元關機及輸出端口熔絲保護等措施快速隔斷直流危險電壓到輸出端口的路徑。在保護過程中，輸出到負載端口的電壓約為持續(xù)幾個ms的400V直流。對于使用開關電源供電的IT負載來說，其輸入允許電壓可以達到276Vac，整流之后電壓也在400Vdc左右，器件選型等均依據(jù)母線電壓選型。此時輸入端口的400Vdc不會超出器件耐受范圍，不可能對設備造成傷害。而對于工頻機而言，其原邊加載直流電壓，將導致電流急劇增大，溫度快速上升，可能引發(fā)火災等更嚴重故障。

第三，可以降低零地電壓。許多服務器等設備都有零地電壓的要求，盡管這樣設計的原因已無法考證，因為從理論上來說零地電壓的大小并不會影響IT設備的正常工作。在數(shù)據(jù)中心中，IT設備只允許使用TN-S或TN-C-S供電制式，那么IT設備輸入端口的零地電壓主要由零線接地點(TN-S系統(tǒng))或零線與地線分離點(TN-C-S系統(tǒng))至IT輸入端口的零線阻抗與零線電流及系統(tǒng)中三次諧波電流決定。在相同的系統(tǒng)中，無論是工頻機還是高頻機均不會影響零線阻抗，而零線電流及三次諧波電流主要是與三相負載配置與負載特性有關，即UPS的類型不會對于零地電壓不會有明顯的影響。真正決定零地電壓的是配電系統(tǒng)的設計。如果需要改善零地電壓，是從配電系統(tǒng)入手，著手減少線路阻抗與零線電流。減少線路阻抗的方式即在負載的列頭柜內(nèi)置隔離變壓器。需要注意的是在應用時有將工頻機變壓器副邊直接接地的做法，這是一種不規(guī)范的做法。工頻機變壓器N線并未隔離，對于TN-S系統(tǒng)和N與PE已經(jīng)分開的TN-C-S系統(tǒng)，N線重新接地也將導致PE線有電流流過，可能干擾設備正常工作。國標還是IEC標準均不允許此種不規(guī)范做法。

而第四，工頻UPS的變壓器可以起到隔離作用，可以保障人身安全。為了保障主旁平穩(wěn)切換，工頻UPS輸出N線由旁路引入，也即工頻機的變壓器并不能起到電氣隔離作用，也不能重新接地。在需要隔離場合的場景，即使使用工頻UPS，其旁路也必須加一變壓器用于隔離N線，以實現(xiàn)真正的隔離。

實際上，變壓器的設計反而增大了環(huán)流的風險。圖-3所示為兩類機型的環(huán)流路徑。工頻機UPS的并聯(lián)就是變壓器的直接并聯(lián)，整條回路上沒有器件限制，電壓的偏差很容易產(chǎn)生環(huán)流。而高頻機的環(huán)流路徑上具備多個二極管，小于2V的電壓差根本形不成環(huán)流。

圖-3 工頻機與高頻機并機環(huán)流路徑

5.工頻機增加用戶投資

由于工頻機整流工作在市電頻率，需要更大的電感儲能。其更大體積的電感與無法省掉的變壓器均由銅和磁性材料組成，成本難以下降，價格一般比高頻機要高30%以上。

中興ZXDU58 W121室外一體化通信電源機柜

綜上，從性能、可靠性、價格上講，高頻機比工頻機均具備優(yōu)勢。從各主要廠家的系列來看，業(yè)界主要廠商均已不推出新工頻機型，部分廠商已全面轉(zhuǎn)向高頻機的研發(fā)與銷售。工頻機被高頻機取代已是大勢所趨。

三、從高頻塔式機UPS到模塊化UPS的發(fā)展

模塊化UPS早在上世紀九十年代即已出現(xiàn)，但因為技術(shù)能力沉寂了很長時間。而自2000年起，由于DSP、數(shù)字控制等技術(shù)的發(fā)展，多功率模塊并聯(lián)均流控制問題得以逐步解決，模塊化UPS技術(shù)開始蓬勃發(fā)展。2009-2010年中國電信對模塊化UPS展開深入測試，根據(jù)各地實際使用單位的反饋，中國電信認為業(yè)界主流模塊化UPS已滿足通信行業(yè)的使用要求，并于2011年底開始對模塊化UPS進行集中采購。中國移動模塊化UPS也以單獨標段進行集采。

四、模塊化UPS與高頻塔式UPS的對比

1.模塊化UPS系統(tǒng)可用性高

供配電系統(tǒng)作為現(xiàn)在信息系統(tǒng)極為重要的一環(huán)，對其一個基本的要求就是該系統(tǒng)必須能連續(xù)工作。而要達到連續(xù)工作這一目的，首先是系統(tǒng)應具備較高的可靠性，其次該系統(tǒng)必須做到能夠快速修復。如果不能快速修復，就可能面臨二次故障導致整個系統(tǒng)癱瘓的風險，客戶的負載就不能保障連續(xù)工作。

在快速修復方面，模塊化UPS具備天生優(yōu)勢。首先，在修復時間上，由于快速插拔這一特性，模塊化UPS現(xiàn)場即可完成更換，平均的修復時間在半小時之內(nèi)，相比于傳統(tǒng)塔式機典型修復時間24小時，修復速度明顯提升。其次，在修復質(zhì)量上，模塊化UPS的修復形式是將故障模塊更換，而傳統(tǒng)塔式機需要原廠派專業(yè)工程師到現(xiàn)場進行故障定位，然后拆機修復故障電路、單板，修復周期長，而且存在溝通和定位過程，易造成重復工作，影響故障處理效率。

可能有的用戶會質(zhì)疑，認為模塊化UPS的N+1體系結(jié)構(gòu)不如1+1并機系統(tǒng)穩(wěn)定。確實，從理論上來講，N+1并機系統(tǒng)中1+1的可靠性肯定是的。但是實際的場景中往往不是這么簡單：

首先，此結(jié)論忽略了負載率這一情況，作為1+1并機系統(tǒng)，最多只能允許一臺UPS損壞；而對于模塊化UPS體系，以4+1為例，99%負載的時候可靠性要低于1+1，但是75%負載率的時候，模塊化體系實際就變成了3+2，50%的時候就變成了2+3，可靠性要遠大于1+1并機。在常見應用場景中，UPS負載率是在20~40%左右的，在這種情況下模塊化的優(yōu)勢具有非常明顯的優(yōu)勢。

其次，不同于傳統(tǒng)單機，模塊化UPS可以輕易實現(xiàn)N+2、N+3這種冗余模式，僅需增加1-2個模塊即可實現(xiàn)，而塔式機要做到此模式不僅僅是增加1臺主機，機器運輸、場地安裝、走線設計以及相應的配電、電池都需變更，導致投資大幅增加。

綜上，UPS模塊化在實際場景中可靠性遠高于傳統(tǒng)塔式并機；再加上UPS快速維護、擴容的特性，模塊化UPS的可用性更是大大高于傳統(tǒng)塔式機。

2.模塊化UPS的擴展性更好

塔式機擴容需要購買整臺新機、將機器安裝到位、將系統(tǒng)中其他UPS轉(zhuǎn)旁路后把新機接入系統(tǒng)，整個步驟中不僅投資高、安裝時間長，而且在并入新機時由于整個系統(tǒng)處于旁路狀態(tài)，存在市電中斷導致負載掉電的風險。

而模塊化只要初期規(guī)劃好配電系統(tǒng)，就可以通過增加模塊來匹配負載的提升，且在擴容過程中保障對原有負載的不間斷供電。

3.模塊化UPS運輸安裝難度低

塔式機UPS需要作為一個整體來安裝、運輸，大型單機就會比較困難。如容量400kVA的UPS重量一般為1500kg左右，體積超過3m3，塔式機UPS會受到運輸通道不足、重量高難運輸?shù)睦щy，而模塊化UPS一方面可以將模塊、機架分開搬運，另一方面多數(shù)機型機架之間可以分開運輸，塔式UPS可能遇到的問題將迎刃而解。

4.模塊化UPS實際運行效率高

目前高頻塔式UPS與模塊化UPS均可做到96%的效率值，但這是在負載率在50%以上才能達到的。而前面提到，因為系統(tǒng)冗余及超前規(guī)劃，常見工況下UPS負載率在20~40%左右。高頻塔式機在此工況下只能做到94~95%的效率，而主流模塊化UPS普遍具備“模塊休眠"特性在保證一定系統(tǒng)冗余的基礎上，可以休眠一定數(shù)量的模塊（可以手動或者設置自動），讓UPS系統(tǒng)工作在效率比較高的區(qū)域，即保持在高點96%附近。圖-4即展示了休眠提升負載率中興ZXDU58 W121室外一體化通信電源機柜與運行效率的原理。

圖-4 休眠可有效提升UPS負載率與運行效率

而且有些廠家考慮到模塊老化時間可能不同，更進一步開發(fā)了“輪換休眠功能"：即每隔一段設定好的周期，休眠模塊進行輪換，以平均每個模塊的老化時間，提升整體UPS系統(tǒng)壽命。圖-5展示了輪換休眠的典型過程。

圖-5 輪換休眠技術(shù)

五、結(jié)束語

自其誕生之日起，模塊化UPS就旨在滿足用戶對于供電系統(tǒng)的可用性、可靠性、可維護性及節(jié)能等方面的需求。經(jīng)過長期的運行驗證，模塊化UPS在這些方面相較傳統(tǒng)UPS系統(tǒng)確實具備很大優(yōu)勢。隨著能源成本持續(xù)增加及用戶對供電系統(tǒng)的靈活性、可用性等要求的進一步提高，模塊化UPS必將得到更廣泛的應用。

At present, UPS products have been used in the industry for more than fifty years. It has made outstanding contributions to ensure the uninterrupted operation of key equipment and business. With the continuous advancement of information construction, more and more scenes of UPS protection are needed, and its role is becoming more and more important. There are three kinds of products in the current market, such as power frequency machine, high frequency tower type machine and high frequency modular UPS. The advantages and disadvantages of these products are different, which makes the users feel very confused. This article aims to help users identify the trend of the development of UPS products by explaining the history of the development of UPS and comparing the advantages and disadvantages of various kinds of UPS.

1. The development of UPS from UPS to high frequency tower machine

The power frequency machine structure UPS technology appeared in the 70s of last century, because the frequency of its rectification work is consistent with the frequency of the power grid. Subject to the development of semiconductor technology, the inverter IGBT breakdown voltage can only 600V, so the bus voltage is limited, the output voltage of the inverter can achieve 380V; and motor inverter is the full bridge circuit, output voltage line, unable to meet the load demａnd of IT single-phase four wire and three-phase load, must be a -Y conversion. In order to solve these problems, the transformer is added to the output terminal of the power frequency inverter, which is used to boost and generate the midline, so that the output voltage can meet the load requirements, which is the real purpose of the transformer built in the power frequency machine. The typical topology of the industrial frequency machine is shown in figure -1.

Figure -1 typical topology of power frequency machine

In the 90s of the last century, the third generation of trench type IGBT came out, and its pressure resistance increased to 1200V, prompting the innovation of UPS technology. Through the high frequency boost circuit of the rectifier side, the bus voltage is raised to about 700V, the output voltage of the inverter can be 380V, and the output transformer can be cancelled. This rectifier inverter circuit works at high frequency (a few kHz above) and UPS without output transformer is called high frequency UPS. Figure -2 is shown as a typical high-frequency machine topology.

Figure -2 typical topology of high frequency machine

Comparison of two, high frequency UPS and power frequency UPS

The input power factor of 1. power frequency machine is low and the harmonic is high

中興ZXDU58 W121室外一體化通信電源機柜

The power machine UPS using thyristor half controlled rectifier, 6 pulse rectifier UPS input power factor is less than 0.7, up to 30% harmonics; 12 pulse rectifier UPS maximum input power factor is only 0.8, harmonic as high as 15%, even with the harmonic treatment measures, the highest power factor can only be improved to 0.95. In contrast, the high frequency machine adopts the IGBT-PFC full control rectifier, and the input power factor industry can achieve 0.99 and the harmonic current is less than 3%. Serious harmonic pollution not only may interfere with other equipment can not work and the malfunction of control and protection devices, but also directly lead to a substantial increase in investment: customers need to purchase additional equipment to reduce the harmonic harmonic treatment; if the front end is connected with a diesel generator power generator, the capacity to be configured as 2-3 times the capacity of UPS, at the same time before distribution device cable, etc. need to increase by 20%, while the high frequency machine just in front of the generator capacity configuration for the 1.2-1.5 times UPS capacity, distribution capacity and UPS capacity is the same as or slightly high.

2. power frequency machine power consumption is big

There are three factors that cause the efficiency of the power frequency UPS to be lower than the high frequency UPS. One is the frequency UPS rectifier for buck topology, device working current, both internal lines of both the linear loss or square loss than high frequency machine; two is the reason for the need to boost the power output than the high-frequency machine with an output transformer, the power machine efficiency decreased about 2%-3%; three is in the practical application in order to improve the input power factor, to more than 0.95, and decrease the injection of harmonic pollution, but also a power machine external 5 or 11 harmonic filter, the efficiency will drop again 2%-3%. According to the data from a British operator and a Spanish operator, the efficiency of power frequency UPS is generally around 85%, which is much higher than the operation efficiency of 92% and the efficiency of modularization is about 96%, resulting in a large number of energy losses. Taking the 400kW load as an example, the power frequency machine will consume more than 410 thousａnd degrees more than the high frequency machine, and will consume more than 580 thousａnd degrees more than the modular year. In addition, the power frequency UPS and the high harmonic, low power factor and so on lead to the increase of distribution cable loss and so on.

3. power frequency machine is large in volume and weight weight

Because the frequency machine uses low frequency devices and the output transformer is configured, the volume weight of UPS is greatly increased. In contrast to a certain brａnd of 400kVA frequency machine and high frequency machine, power machine is 2.2 times heavier than the high frequency machine, high frequency machine volume is 1.5 times, maybe the problem is too small, the room door or aisle elevator load is not enough, the lack of floor bearing in actual transportation, even in some cases need 中興ZXDU58 W121室外一體化通信電源機柜to use the crane loading and unloading, and then break through the wall to install in the frequency UPS, greatly increasing the transportation time and cost.

4. frequency machines have no advantages in reliability compared to high frequency machines

The main differences between the frequency machine and the high frequency machine are reflected in the rectifier and the transformer. The power frequency machine rectifier uses SCR device, the voltage stress is small, the current stress is big, the high frequency machine mainly adopts the IGBT device, the current stress is small, and the voltage stress is big. SCR and IGBT are all mature devices at present. As long as they are properly applied, there is no difference in reliability. In fact, the inverter part of the power frequency machine also uses IGBT, which does not reduce the reliability of the power frequency machine. There is no evidence that the inverter is the weak link of the power frequency machine. From the topological point of view, the frequency machine uses phase controlled rectifier + full bridge inverter, high frequency machine ge中興ZXDU58 W121室外一體化通信電源機柜nerally adopts high frequency rectifier + half bridge inverter. These topologies are all very common topologies in power electronics, and there is no problem that is more reliable in principle, and its reliability depends on the level of the design.

For transformers, the industry can often hear a lot of its so-called advantages, such as strong impact resistance, reduction.

中興ZXDU58 W121室外一體化通信電源機柜

中興ZXDU58 W121室外一體化通信電源機柜