【正文】 5 列出文獻(xiàn) 1 Retrieved from 2 、 3 S. Madhava Rao,Power system protection: static relays with microprocessor applications , Tata McGrawHill, 1989, ISBN 0074603078, pp 12, C. Russel Mason, The Art and Science of Protective Relaying, General Electric, available at [1] 。 2 機(jī)電保護(hù)繼電器或 磁操作的吸引力，或磁感應(yīng) 的介紹 。 inconvenient high voltages are required for the circuits, and vacuum tube amplifiers had difficulty with incorrect operation due to noise disturbances. 句 中 be required to 的意思是被需求， due to 的意思是由于。 (b) The returning ratio or differential is the measure of how much the current must be reduced to reset the relay. 這是個(gè)賓語從句， how much 指代 of后 面的賓語。靜態(tài)繼電器 elminated 或減少接觸反彈，并能提供快速的操作，使用壽命長，維護(hù)成本低。不方便高電壓所需的電路，真空管放大器有不正確的操作難度，由于噪聲干擾 靜態(tài)繼電器，沒有或很少運(yùn)動(dòng)部件成為與晶體管的引進(jìn)實(shí)用。設(shè)備采 用電子管應(yīng)用進(jìn)行了研究，但從未作為商品由于真空管放大器的limitatons。如果有兩個(gè)或多個(gè)線圈的使用，否則他們必須在沒有凈營業(yè)力產(chǎn)生相同的頻率。磁盤的旋轉(zhuǎn)運(yùn)動(dòng)經(jīng)營聯(lián)系。另一種動(dòng)圈式暫停從兩個(gè)導(dǎo)電線圈韌帶，使很長的線圈旅行。 “移動(dòng)線圈 ”米使用的線圈在固定磁鐵，類似于振但有聯(lián)系，而不是一個(gè)指針桿轉(zhuǎn)。 一個(gè)變種的吸引力原則應(yīng)用是柱塞式 或電磁運(yùn)營商。由于線圈之間的固定和移動(dòng)電樞空氣的差距變得更小的繼電器操作時(shí)，必須保持繼電器關(guān)閉電流比目前首先操作更小。 “電樞 ”型繼電器有一個(gè)無所不能杠桿上的鉸鏈或刀口支點(diǎn)，這 carrys 一動(dòng)觸頭的支持。然而，由于他們的壽命很長，這些 “沉默的哨兵 ”仍然保護(hù)數(shù)以萬計(jì)世界各地輸電線路和電氣設(shè)備。今天，這些設(shè)備幾乎完全取代微處理器為基礎(chǔ)的數(shù)字保護(hù)繼電器（數(shù)字繼電器）來模擬在以極大的精度和應(yīng)用方便的機(jī)電祖先。例如，一個(gè) 51 中繼功能將包括一個(gè)定時(shí)過電流保護(hù)繼電器。一個(gè)重要的輸電線路或發(fā)電機(jī)組將擁有專門的保護(hù)與許多個(gè)別機(jī)電設(shè)備，板間房。為響應(yīng)保護(hù)繼電器過電流，過電壓，反向功率流，過壓和下頻率的條件。不同于通常有固定和不明確的工作電壓和工作時(shí)間的閾值開關(guān)型繼電器，保護(hù)繼電器的完善，可選 /電流（或其他操作參數(shù)）曲線，時(shí)間。 if two or more coils are used, they must be at the same frequency otherwise no operating force is produced. Keywords： electromechanical protective relays From reference 3 Application of electronic amplifiers to protective relays was described as early as 1928, using vacuum tube amplifiers. Devices using electron tubes were studied but never applied as mercial products, because of the limitatons of vacuum tube amplifiers. A relatively large standby current is required to maintain the tube filament temperature。 5 列出文獻(xiàn) (1) (2) (3)Come from . Page3. Protective Relays(繼電器 ) From reference 1 In electrical engineering, a protective relay is a plex electromechanical apparatus, often with more than one coil, designed to calculate operating conditions on an electrical circuit and trip circuit breakers when a fault is detected. Unlike switching type relays with fixed and usually illdefined operating voltage thresholds and operating times, protective relays have wellestablished, selectable, time/current (or other operating parameter) curves. Such relays may be elaborate, using arrays of induction disks, shadedpole mags, operating and restraint coils, solenoidtype operators, telephonerelay contacts, and phaseshifting works. Protection relays respond to such conditions as overcurrent, , reverse power flow, over and under frequency. Distance relays trip for faults up to a certain distance away from a substation but not beyond that point. An important transmission line or generator unit will have cubicles dedicated to protection, with many individual electromechanical devices. The various protective functions available on a given relay are denoted by standard ANSI Device Numbers. For example, a relay including function 51 would be a timed overcurrent protective relay. Design and theory of these protective devices is an important part of the education of an electrical engineer who specializes in power systems. Today these devices are nearly entirely replaced with microprocessorbased digital protective relays (numerical relays) that emulate their electromechanical ancestors with great precision and convenience in application. By bining several functions in one case, numerical relays also save capital cost and maintenance cost over electromechanical relays. However, due to their very long life span, tens of thousands of these silent sentinels are still protecting transmission lines and electrical apparatus all over the world. Keywords： protective relay From reference 2 Electromechanical protective relays operate by either magic attraction, or magic induction. Armaturetype relays have a pivoted lever supported on a hinge or knifeedge pivot, which carrys a moving contact. These relays may work on either alternating or direct current, but for alternating current, a shading coil on the pole is used to maintain contact force throughout the alternating current cycle. Because the air gap between the fixed coil and the moving armature bees much smaller when the relay has operated, the current required to maintain the relay closed is much smaller than the current to first operate it. The returning ratio or differential is the measure of how much the current must be reduced to reset the relay. A variant application of the attraction principle is the plungertype or solenoid operator. A reed relay is another example of the attraction principle. Moving coil meters use a loop of wire turns in a stationary mag, similar to a galvanometer but with a contact lever instead of a pointer. These can be made with very high sensitivity. Another type of moving coil suspends the coil from two conductive ligaments, allowing very long travel of the coil. Induction disk meters work by inducing currents in a disk that is free to rotate。 2 介紹了 卡特彼勒公司和 CAT 發(fā)電機(jī) ， 卡特彼勒