【正文】 microputer protection function. (2) dimension and structure and the current protection device, exquisite workmanship, shockproof, prevent overheating, preventing electromagic interference ability is strong, can run in very bad working environment, cost can be accepted. (3) using STD bus or PC bus, hardware modular, for different protection can be arbitrarily choose different modules, flexible configuration, easy extension. The microputer relay protection device, puterized is irreversible trend. But how to better satisfy power system, how to further improve the reliability of the relay protection, and how to obtain more economic benefit and social benefit, still must specifically indepth research. 820 works The puter work information and data munication tool has bee the mainstay of the information age, make human production technology and social life of the fundamental changes have taken place. It is deeply affect all industries, as well as various industry provides powerful means of munication. So far, in addition to the differential protection disoperation and protection of the relay protection device, all can only protect the 桂林電子科技大學(xué)畢業(yè)設(shè)計(jì)英文資料 翻譯 6 electricity installation reaction. Protection function is limited, reduce accidents resection fault ponents. This is mainly due to the lack of data munications. Strong Foreign had put forward the concept of protection system, which was mainly refers to the safety automatic device. Because of the relay protection function not only fault ponents and limit resection impact accident (this is to ensure priority), the safe and stable operation of the whole system. This requires each protection unit can be altogether I、 Conclusion Discussed above in the switching regulator of a variety of conservation, and introduces a number of specific ways to achieve. Of a given switching power supply is concerned, but also protection from the whole to consider the following points: 1) The switching regulator used in the switching transistor in the DC security restrictions on the work of regional work. The transistor switches selected by the manual available transistors get DC safe working area. According to the maximum collector current to determine the input value of overcurrent protection. However, the instantaneous maximum value should be converted to the average current. At rated output current and output voltage conditions, the switch of the dynamic load line does not exceed a safe working area DC maximum input voltage, input overvoltage protection is the voltage value. 2) The switching regulator output limit given by the technical indicators within. Work within the required temperature range, the switching regulator39。s output voltage, the lower limit of the output is off, due to the voltage value of voltage protection. Overcurrent protection can be based on the maximum output current to determine. False alarm in order not to protect the value of a certain margin to remain appropriate. 3) From the above two methods to determine the protection after the power supply device in accordance with the needs of measures to determine the alarm. Measures the general alarm sound and light alarm two police. Voice of the police applied to more plex machines, power supply parts and do not stand out in a place, it can give staff an effective warning of failure。 optical Police instructions can be eyecatching and fault alarm and pointed out that the fault location and type. Protection measures should be protected as to determine the location. In the highpower, multichannel power supply, always paying, DC circuit breakers, relays, etc. highsensitivity autoprotection measures, to cut off the input power supply to stop working the system from damage. Through the logic control circuit to make the appropriate program cutoff switch transistor is sensitive it is convenient and economic. This eliminated large, long response time, the price of your highpower relay or circuit breaker. 4) The power of putting in the protection circuit will be affected after the reliability of the system, for which want to protect the reliability of the circuit itself is higher in order to 桂林電子科技大學(xué)畢業(yè)設(shè)計(jì)英文資料 翻譯 7 improve the reliability of the entire power system, thereby increasing its own power supply MTBF. This requires the protection of strict logic, the circuit is simple, at least ponents, In addition to the protection circuit should also be considered a failure of maintenance of their difficulty and their power to protect the damage. Therefore, we must be prehensive and systematic consideration of a variety of switching power supply protection measures to ensure the normal operation of switching power supplies and highefficiency and high reliability. 桂林電子科技大學(xué)畢業(yè)設(shè)計(jì)英文資料 翻譯 8 直流開(kāi)關(guān)穩(wěn)壓電源的保護(hù)技術(shù) 摘要 ：討論了直流開(kāi)關(guān)穩(wěn)壓電源的保護(hù)系統(tǒng) ,提出保護(hù)系統(tǒng)設(shè)計(jì)的原則和整機(jī)保護(hù)的措施，分析了開(kāi)關(guān)穩(wěn)壓電源中的各種保護(hù)的特點(diǎn)及其設(shè)計(jì)方法 ,介紹了幾種實(shí)用保護(hù)電路。 關(guān)鍵 字 ：開(kāi)關(guān)電源；保護(hù)電路；系統(tǒng)設(shè)計(jì) 一、引言 直流開(kāi)關(guān)穩(wěn)壓器中所使用的大功率開(kāi)關(guān)器件價(jià)格較貴 ,其控制電路亦比較復(fù)雜 ,另外 ,開(kāi)關(guān)穩(wěn)壓器的負(fù)載一般都是用大量的集成化程度很高的器件安裝的電子系統(tǒng)。晶體管和集成器件耐受電、熱沖擊的能力較差。因而開(kāi)關(guān)穩(wěn)壓器的保護(hù)應(yīng)該兼顧穩(wěn)壓器本身和負(fù)載的安全。保護(hù)電路的種類(lèi)很多 ,這里介紹極性保護(hù)、程序保護(hù)、過(guò)電流保護(hù)、過(guò)電壓保護(hù)、欠電壓保護(hù)以及過(guò)熱保護(hù)等電路。通常選用幾種保護(hù)方式加以組合 ,構(gòu)成完善的保護(hù)系統(tǒng)。 二、極性保護(hù) 直流開(kāi)關(guān)穩(wěn)壓器的輸入一般都是未穩(wěn) 壓直流電源。由于操作失誤或者意外情況會(huì)將其極性接錯(cuò) ,將損壞開(kāi)關(guān)穩(wěn)壓電源。極性保護(hù)的目的 ,就是使開(kāi)關(guān)穩(wěn)壓器僅當(dāng)以正確的極性接上未穩(wěn)壓直流電源時(shí)才能工作。利用單向?qū)ǖ钠骷梢詫?shí)現(xiàn)電源的極性保護(hù)。最簡(jiǎn)單的極性保護(hù)電路如圖 1 所示。由于二極管 D 要流過(guò)開(kāi)關(guān)穩(wěn)壓器的輸入總電流 ,因此這種電路應(yīng)用在小功率的開(kāi)關(guān)穩(wěn)壓器上比較合適。在較大功率的場(chǎng)合 ,則把極性保護(hù)電路作為程序保護(hù)中的一個(gè)環(huán)節(jié) ,可以省去極性保護(hù)所需的大功率二極管 ,功耗也將減小。為了操作方便 ,便于識(shí)別極性正確與否 ,在二極管之后接指示燈。 三、程序保護(hù) 開(kāi)關(guān)穩(wěn)壓電源的電路比較復(fù)雜 ,基本上可以分為小功率的控制部分和大功率的開(kāi)關(guān)部分。開(kāi)關(guān)晶體管則屬大功率，為保護(hù)開(kāi)關(guān)晶體管在開(kāi)啟或關(guān)斷電源時(shí)