【正文】 possible conditions due to the fact that this will make the whole system highly therefore, if such an abnormality takes place in any element or ponent of the power system network, it is desirable that the affected element/ponent is removed from the rest of the system reliably and quickly in order to restore power in the remaining system under the normal condition as soon as protection scheme includes both the protective relays and switching circuits, t protective relay which functions as a brain is a very important protective relay is a sensing device, which senses the fault, determines its location and then sends mand to the proper circuit breaker by closing its trip circuit breaker after getting mand from the protective relay disconnects only the faulted is why the protective relay must be reliable, maintainable and fast in early days, there used to be electromechanical relay of induction r, very soon the disk was replaced by inverted cup, cylinder and the new relay obtained was known as an induction cup or induction cylinder relay, which is still in use, possesses several important features such as higher speed。置無關(guān)；③ 故障線路，兩端零序功率的方向與正斯保護(hù)過熱保護(hù)等。電力系統(tǒng)運(yùn)行方式變因此,稱之為近后備保護(hù)。于自并勵(lì)發(fā)電機(jī) ⑤ 對(duì)于由不對(duì)稱負(fù)荷或外部不對(duì)繼電保護(hù)按反應(yīng)故障和按其功用的不同可分為稱短路所引起的負(fù)序過電流，一般在50mw及以哪些類型?答:(1)按反應(yīng)故障可分為:相間短路保護(hù),接地短路保護(hù),匝間短路保護(hù),失磁保護(hù)等。用于50mw及以上的發(fā)電機(jī)② 復(fù)合電壓(？ ？ 電壓及線電壓)啟動(dòng)的過電流保護(hù)，一般用于1mw阻抗繼電器在阻抗復(fù)平面動(dòng)作區(qū)域的形狀，成為答：無論起動(dòng)和返回，繼電器的動(dòng)作都是明確干脆及以上的發(fā)電機(jī)③ 過電流保護(hù)用于1mw以下的小動(dòng)作特性。接、每相有并聯(lián)分支且中性點(diǎn)側(cè)有分支引出端時(shí)，于本身的對(duì)地電容電流，電容性無功功率的實(shí)際方向由母線流向線路。？其基本任務(wù)是什么？一個(gè)其值與故障相故障前相電壓大小相等。機(jī)額定容量而引起的三相對(duì)稱過負(fù)荷(3)？有何特點(diǎn)？對(duì)稱短路或不對(duì)稱負(fù)荷(如單相負(fù)荷，非全相運(yùn)行變壓器差動(dòng)保護(hù)中怎樣克服勵(lì)磁涌流的影響？ 等)而引起的發(fā)電機(jī)負(fù)序過電流和過負(fù)荷答：當(dāng)變壓器空載投入和外部故障切除后電壓恢復(fù)一般發(fā)電機(jī)應(yīng)裝設(shè)以下繼電保護(hù)裝置 時(shí)，可能出現(xiàn)很大的勵(lì)磁電流（又稱為勵(lì)磁涌流）。發(fā)電機(jī)的內(nèi)部故障主要是由定子繞組及轉(zhuǎn)子繞組連接濾波器,高頻收發(fā)信機(jī),接地開關(guān) 雙側(cè)電源的聯(lián)絡(luò)線上采用單相重合閘，在故障時(shí)大絕緣損壞引起的，常見故障有：(1)定子繞組相間大加強(qiáng)兩個(gè)系統(tǒng)之間的聯(lián)系，提高系統(tǒng)并列運(yùn)行的短路(2)定子繞組單相匝間短路(3)定子繞組單動(dòng)態(tài)穩(wěn)定性。不足:對(duì)于運(yùn)行方式變化很大或接地點(diǎn)變化很大的電網(wǎng),不能滿足系統(tǒng)運(yùn)行的要求單相重合閘過程中,系統(tǒng)又發(fā)生震蕩,可能出現(xiàn)較大零序電流的情況,影響零序電流保護(hù)的正確工作當(dāng)采用自偶變壓器聯(lián)系兩個(gè)不同電壓等級(jí)的電網(wǎng),任一側(cè)發(fā)生接地短路都將在另一側(cè)產(chǎn)生零序電流,使得零序電流保護(hù)整定計(jì)算復(fù)雜化射線路中，重合閘裝置僅裝在靠近電源的一段線路上。接線方式含義:當(dāng) cosψm=1 時(shí),加入繼電器的電壓和電流夾角為 0o,用，)與相電流保護(hù)相比：。相信許多人會(huì)覺得范文很難寫？接下來小編就給大家介紹一下優(yōu)秀的范文該怎么寫，我們一起來看一看吧。電力系統(tǒng)繼電保護(hù)基本原理篇一2有選擇性的接地保護(hù)裝置：保護(hù)直接連于母線。高、動(dòng)作時(shí)限短2零序電流保護(hù)相比相間短路的電重合閘前加速保護(hù)一般稱為“前加速”。所謂后加速就是當(dāng)線路第一次故障時(shí)，保護(hù)有選擇性的動(dòng)作，然后自行重合。相接地(4)轉(zhuǎn)子繞組一點(diǎn)接地或兩點(diǎn)接地(5)轉(zhuǎn)子缺點(diǎn)：需要有按相操作的斷路器。(1)對(duì)1mw以上發(fā)電機(jī)的定子繞組及其引出線的特點(diǎn)：① 包含有大量的非周期分量，使涌流偏向相間短路，應(yīng)裝設(shè)縱差保護(hù)裝置(2)對(duì)直接連于時(shí)間軸一側(cè)；② 包含有大量的高次諧波，而且以母線的發(fā)電機(jī)定子繞組單相接地故障，當(dāng)單相接地故障電流(不考慮消弧線圈的補(bǔ)償作用)大于規(guī)定允許值時(shí)，應(yīng)裝設(shè)有選擇性的接地保護(hù)裝置；對(duì)于發(fā)電機(jī)——變壓器組，對(duì)容量在100mw以下的發(fā)電機(jī)，應(yīng)裝設(shè)保護(hù)區(qū)不小于定子繞組串聯(lián)匝數(shù)90%的定子接地保護(hù)；對(duì)容量在100mw及以上的發(fā)電機(jī)，應(yīng)裝設(shè)保護(hù)區(qū)為100%的定子接地保護(hù)，保護(hù)和勵(lì)磁涌流產(chǎn)生原因:鐵芯中的磁通不能突變涌流的大小的影響因素:合閘角、剩磁、鐵芯飽和特性等 二次諧波為主；③ 波形之間出現(xiàn)間斷——。方向相答：能反應(yīng)電力系統(tǒng)中電氣元件發(fā)生故障或者不正帶時(shí)限動(dòng)作于信號(hào)，必要時(shí)動(dòng)作于切機(jī)(3)對(duì)于 反的零序電壓。，其數(shù)值為全系統(tǒng)非故障元件對(duì)地電容電流之總和，電容性無功基本任務(wù)是：自動(dòng)、迅速、有選擇性地將故障元件從電力系統(tǒng)中切除，使故障元件免于繼續(xù)遭到破壞，保證其他無故障部分迅速恢復(fù)正常運(yùn)行。動(dòng)作特性包括。上的發(fā)電機(jī)上裝設(shè)負(fù)序過電流保護(hù)⑥ 對(duì)于由對(duì)稱負(fù)荷引起的發(fā)電機(jī)定子繞組過電流，應(yīng)裝設(shè)接于一相電流的過負(fù)荷保護(hù) ⑦ 對(duì)于水輪發(fā)電機(jī)定子繞組(2)按其功用可分為:主保護(hù)、后備保護(hù)、輔助保護(hù) 過電壓，應(yīng)裝設(shè)帶延時(shí)的過電壓保護(hù)⑧ 對(duì)于發(fā)電機(jī)三段式電流保護(hù)的評(píng)價(jià)及應(yīng)用 勵(lì)磁回路的一點(diǎn)接地故障，:通過動(dòng)作電流、動(dòng)作時(shí)間來保證選擇性 發(fā)電機(jī)可裝設(shè)定期檢測裝置；對(duì)1mw以上的發(fā)電機(jī)應(yīng)裝設(shè)專用的勵(lì)磁回路一點(diǎn)接地保護(hù)⑨ 對(duì)于發(fā)電機(jī)勵(lì)磁消失故障，在發(fā)電機(jī)不允許失磁運(yùn)行時(shí)，應(yīng)在自動(dòng)滅磁開關(guān)斷開時(shí)連鎖斷開發(fā)電機(jī)的斷路平衡電流 單相電源輻射網(wǎng)絡(luò)上可以保證獲得選擇性 ？ 性:無時(shí)限速斷和帶時(shí)限速斷保護(hù)動(dòng)作是迅速的電力系統(tǒng)振蕩時(shí)，阻抗繼電器是否誤動(dòng)、誤動(dòng)的過電流保護(hù)則常常不能滿足速動(dòng)性的要求 時(shí)間長短與保護(hù)安裝位置、保護(hù)動(dòng)作范圍、動(dòng)作特性:運(yùn)行方式變化較大時(shí),速斷保護(hù)往往不能滿足要器；對(duì)采用半導(dǎo)體勵(lì)磁以及100mw及以上采用電性的形狀和振蕩周期長短等有關(guān)，安裝位置離振蕩求 被保護(hù)線路很短時(shí),無限時(shí)電流速斷保護(hù)長為零動(dòng)機(jī)勵(lì)磁的發(fā)電機(jī)，應(yīng)增設(shè)直接反應(yīng)發(fā)電機(jī)失磁時(shí)中心越近、整定值越大、動(dòng)作特性曲線在與整定阻靈敏度差 :繼電器簡單、數(shù)電氣參數(shù)變化的專用失磁保護(hù)⑩ 對(duì)于轉(zhuǎn)子回路的抗垂直方向的動(dòng)作區(qū)域越大時(shí)，越容易受振蕩的影量少、整定計(jì)算和校驗(yàn)容易 可靠性好是它的主要過負(fù)荷，在100mw及以上，并且采用半導(dǎo)體勵(lì)磁響，振蕩周期越長誤動(dòng)的時(shí)間越長。在遠(yuǎn)處實(shí)現(xiàn)對(duì)相鄰元件的行時(shí)，在300mw機(jī)組上，宜裝設(shè)失步保護(hù)；當(dāng)汽化時(shí),間接影響零序分量大??；②零序電流超前于零后備保護(hù), 稱為遠(yuǎn)后備保護(hù)。序功率的相反；④ 由保護(hù)安裝點(diǎn)到到零序網(wǎng)絡(luò)中構(gòu)成方式:測量部分邏輯部分執(zhí)行部分性點(diǎn)之間的零序阻抗決定，與被保護(hù)線路的零序阻后備保護(hù)的作用是什么?抗及故障點(diǎn)的位置無關(guān)；⑤ 系統(tǒng)運(yùn)行方式變化時(shí)，答:后備保護(hù)的作用是在主保護(hù)因保護(hù)裝置拒動(dòng)、只要送電線路和中性點(diǎn)接地變壓器數(shù)目不變，零序保護(hù)回路中的其他環(huán)節(jié)損壞、斷路器拒動(dòng)等原因不 阻抗和零序網(wǎng)絡(luò)就不變。higher torque for a given power input an more uniform r, with the advent of electronic tubes, electronic relays having distinct features were developed during the discovery of solid state ponents during 1950s, static relays with numerous advantages were use of digital puters for protective relaying purposes has been engaging the attention of research and practicing engineers since layer 1960s and , the microprocessor/mini puterbased relaying scheme, because of its numerous advantages such as self –checking feature and flexibility, has been widely used in power system all over the overall system protection is spanided into following sections:(i)generator protection,(ii)transformer protection,(iii)bus protection,(iv)feeder protection,(v)transmission line requirements to protective relays any protection scheme, which ed to safeguard the power system ponents against abnormal conditions such as faults, consists basically of two elements(i)protective relay and(ii)circuit protective relay which is primarily the brain behind the whole scheme plays a very important ore proper care should be taken in selecting an appropriate protective relay which is reliable, efficient and fast in protective relay must satisfy the following requirements: ⑴ since faults on a well designed and healthy system are normally rare, the relays are called upon to operate only means that the relaying scheme is normally idle and must operate whenever fault other words, it must be reliable.⑵ since the reliability partly depends upon the maintenance, the relay must be easily maintainable.⑶ the palpation of the relay can be in two is the failure to operate in case a fault occurs an second is the relay operation when there is no a matter of fact, relay must operate if there is a fault and must not operate if there is no fault.⑷ relaying scheme must be sensitive enough to distinguish between normal and the faulty tive relays the function of the protective relay is to sense the fault and energize the trip coil of the circuit following types of the protective relays are used for the apparatus such as synchronous machines, bus bar, transformer and the other apparatus and transmission line protection.(1)over current relays,(2)under voltage relays,(3)under frequency relays,(4)directional relays,(5)thermal relays,(6)phase sequence relays such as(i)negative sequence relays and,(ii)zero sequence relays,(7)differe