freepeople性欧美熟妇, 色戒完整版无删减158分钟hd, 无码精品国产vα在线观看DVD, 丰满少妇伦精品无码专区在线观看,艾栗栗与纹身男宾馆3p50分钟,国产AV片在线观看,黑人与美女高潮,18岁女RAPPERDISSSUBS,国产手机在机看影片

正文內(nèi)容

電氣專業(yè)畢業(yè)設(shè)計外文資料及中文翻譯(文件)

2024-12-25 20:39 上一頁面

下一頁面
 

【正文】 措施,那么TN-C-S系統(tǒng)可以作為智能型建筑物的一種接地系統(tǒng)。該系統(tǒng)一般用在建筑物的供電由區(qū)域變電所引來的場所,進戶之前采用TN-C系統(tǒng),進戶處做重復接地,進戶后變成TN-S系統(tǒng)。智能化大樓內(nèi),單相負荷所占比重較大,難以實現(xiàn)三相負荷平衡,PEN線的不平衡電流加上線路中存在著的由于熒光燈、晶閘管(可控硅)等設(shè)備引起的高次諧波電流,在非故障情況下,會在中性線N上疊加,使中性線N電壓波動,且電流時大時小極不穩(wěn)定,造成中性點接地電位不穩(wěn)定漂移。在常用的幾種接地方式中,哪一種能夠適合智能化樓宇呢?我們不妨分析一下下面幾種接地系統(tǒng)。統(tǒng)一接地體在建筑物供配電設(shè)計中,接地系統(tǒng)設(shè)計占有重要的地位,因為它關(guān)系到供電系統(tǒng)的可靠性,安全性。電位基準點 中文翻譯: 智能樓宇的電氣保護與接地摘 要: Independent exchanges earth resistance is in conformity with ≤ 4Ω。 In a bit more neutrally power system not grounded directly , the earth electric current flows into the earth through the human body, and form thorough fare by electric capacity by circuit to ground, two situation these can lead to the fact the rights of the person get an electric shock. If the insulation which is equipped with the electric equipment of the earth device is damaged while electrifying outer cover , short out in the electric current and flow through two thorough fares of earth body and human body at the same time in earth, I =IL + IP, we know: In a parallel circuit, the electric current value of passing each branch road is in inverse proportion to size of the resistance.In the type: I Electric current total value in the earth return circuitIL Electric current flowing through along the earth body IP Flow through electric current of the human body Have type can find out earth resistance little , flow through to little electric current have human body, human resistance usually is it ground than earth resistance through electric current of human body electric current of body have several hundred less flowing through too to have several hundred heavier. When earth resistance is extremely small, the electric current that remakable body flows nearly equals zero. Namely I≈IL. In fact, because earth resistance very little, earth short out electric current flow out of date produce press and lower very lightly, so equipment outer cover voltage in earth high. People stand while going to touch the outer cover of the equipment on the earth, the voltage that the human body bears is very low, it can not be dangerous. Is it protect earth device and reduce earth resistance of it to install additional , not only ensure the electric security of system of intelligent building, the effective measure operated effectively, it is not the essential means of equipment and personal security in the intelligent building that ensure too. current is grounded: In a block of intelligent building , include a large number of puters , munication apparatus and automation equipment of building with puter. Importing to information in these electronic equipment, transmission information, change energy , amplify signal, logic movement, output information a series of course go on through little electric potential or little electric current fast, and will often carry on the work through the internet between the equipment. So in order to make its accuracy high, the stability is good, besides needing to have a steady power supply power, must also possess a steady basic electric potential . Can adopt bigger and sectionaller insulating copper core line as the lead wire , one end is connected with basic electric potential directly, another end support electronic equipment direct current earth. It is unsuitable to connect with PE line to deserve and go between , forbid connecting with N line. shielding earth defend static earth: In the intelligent building, it is very important to design electromagnetic and patibly, in order to avoid the dysfunctions of the equipment used, equipment can appear evenned to prevent from damage, form equipment of wiring system should can prevent inside oneself conduct and extraneous interference from. Or because of the coupling phenomenon between the wire in these production that interfere, or because of the electric capacity effect or inductance effect. Main source its superelevation voltage, highpower pieces of radio magnetic field, strike by lightning naturally and static discharge. Phenomenon these will is it send or receive very high to transmit equipment of frequency produce heavy interference very to used for designing. Is it must take the protective measure to equipment the to connect up , avoid the interference from various kinds of respects. Shielding and correct earth to prevent electromagnetic best protection method that interfere. Can connect the equipment outer cover with PE line 。t with other earth system, such as direct current earth, shielding earth, defend static earth is it is it connect to mix to wait for?!here are a large amount of electronic equipment and wiring system in the intelligent building, such as the munication automated system, the fire reports to the police and fire control link the control system , the automated system of the building , monitoring systems of security personnel, office automated system, the closedcircuit TV system,etc., and their corresponding wiring system. By the look of building built, the roof of every storey in the building, the baseplate, the side wall, hang and is nearly covered with by various kinds of wiring while carrying. These electronic equipment and wiring system generally belong to and able to bear the grade of pressing low , defend and interfere expecting muc
點擊復制文檔內(nèi)容
公司管理相關(guān)推薦
文庫吧 www.dybbs8.com
備案圖鄂ICP備17016276號-1