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1、<p> 1800單詞,9500英文字符,中文2900字</p><p> 出處:Kang Y C, Lim U J, Kang S H, et al. A busbar differential protection relay suitable for use with measurement type current transformers[J]. IEEE Transactions on
2、Power Delivery, 2005, 20(2):1291-1298.</p><p><b> 一、英文原文</b></p><p> A Busbar Differential Protection Relay Suitable for Use With Measurement Type Current Transformers</p>&
3、lt;p> YC Kang , UJ Lim , SH Kang , PA Crossley</p><p><b> Abstract</b></p><p> The design, evaluation and implementation of a busbar current differential protection relay suita
4、ble for use with measurement type current transformers (CTs) is described in the paper. The relay operates in conjunction with a saturation detection algorithm, which effectively detects the start and end of each saturat
5、ion period using a technique based on the third-difference function applied to the current signal. A blocking signal is activated immediately after the onset of saturation and is main</p><p> Index Terms—Bl
6、ocking signal and remanent flux, busbar protection, current transformer saturation, difference function, measurement CT.</p><p> INTRODUCTION</p><p> The effect of current transformer (CT) sat
7、uration on a busbar differential protection scheme is of crucial importance during a high-current external fault. The protection must remain stable, but the settings and/or operating technique needed to ensure this, must
8、 not delay or prevent operation on a low-current internal fault. Busbar protection CTs are normally sized for a high over-current factor, but cost and practical limitations mean that saturation cannot be avoided on a sev
9、ere external fault</p><p> Kumar and Hansen proposed a busbar differential relay that operates with a countermeasure for CT saturation. Effectively, a trip signal is only activated if, within 11–14 ms of an
10、 initial trip decision (for a 50 Hz system), the trip criteria is satisfied once again. The double measurement technique ensures stability on external faults, but increases the operating time on internal faults to 25 m
11、s. To ensure a fast response on a high-cur-rent internal fault, the double measurement technique is i</p><p> Sachdev et al. proposed a busbar protection technique that estimates the impedances of the posit
12、ive and negative sequence circuits for every feeder connected to the busbar. The idea is similar to phase angle comparison, i.e. it compares the direction of current flow in each feeder, and consequently is less dependen
13、t on the effect of saturation than an algorithm based on the magnitude of the differential current.An internal fault is detected if all the impedances seen on every feeder are located </p><p> This paper
14、 describes the design, evaluation and implementation of a busbar</p><p> differential relay suitable for operation with measurement CTs. This is achieved using a saturation detection algorith
15、m that blocks the operation of the relay when a CT is saturated and for a period of one cycle after it ends. The logic to discriminate between internal and external faults is achieved by comparing the sequence in which t
16、he protection operating signal and the saturation blocking signal are activated. The pro-posed scheme does not delay the operating time of a relay for an internal</p><p> CURRENT DIFFERENTIAL RELAY OPERATIN
17、G IN CONJUNCTION WITH A SATURATION DETECTION</p><p><b> ALGORITHM</b></p><p> CT Saturation Detection Algorithm</p><p> The CT saturation detection algorithm is brief
18、ly described in this subsection. The algorithm detects the points of inflection in the secondary current that correspond to the start or end of each saturation period. This is achieved using a first-difference function t
19、hat senses the discontinuities and a third-difference function that converts these discontinuities into pulses. The detection algorithm accurately detects the start and end of each saturation period irrespective of the l
20、evel of remane</p><p> The current also contains a point of inflection at fault inception. This results in an initial peak in the third-difference function, which may be incorrectly detected as the</p>
21、;<p> start of saturation. To prevent maloperation, the algorithm is only activated if the current signal exceeds twice the rated current for two successive samples.</p><p> Differential Relay Opera
22、ting With a Saturation Detection Algorithm</p><p> A “Blocking” signal is activated at the start of each saturation period and is</p><p> maintained until the saturation perio
23、d plus an additional one cycle period has ended. The additional delay is required because the DFT window maintains a large differential current value until one cycle after the end of saturation; consequently the locus of
24、 the relay continues to remain in the operating zone. “Blocking” is also activated for an internal fault if a CT saturates, but a “Trip” signal is now issued, because the logic, described in the following paragraph, c
25、an reliably discrimin</p><p> external faults.</p><p> CASE STUDIES</p><p> Fig. 1shows a single line diagram of a typical Korean 154 kV double busbar system with 12 feeders. F
26、eeders 1, 3, 5, 7, 9, and 11 are connected to Bus 1 and feeders 2, 4, 6, 8, 10 and 12 to Bus 2. The two busbars are connected with a bus coupler. For the case studies, two kinds of CTs were chosen:rated protection CTs
27、(used on all Korean 154 kV busbars) andmeasurement CTs. The CTs were modeled based on the method described in using EMTP, this simulates the remanent flux in the core at the ins</p><p> Fig. 1.Single-lin
28、e diagram of simulated system.</p><p> Each CT was connected to a resistive burden of 3.42 and the saturation points for each CT was selected as 5.12 A at 2.9 s for C800 and 2.05 A at 0.15 Vs for C40. Thi
29、s was then used by HYSDAT, an auxiliary program in EMTP, to generate the hysteresis data.</p><p> The current signals were passed through anti-aliasing 1st order RC low-pass filters with a cut-off frequency
30、 of 1920 Hz and then sampled at 64 s/c (3840 Hz at 60 Hz).</p><p> Differential relays 87B1 and 87B2 were used to protect Bus 1 and Bus 2, respectively. 87B1 acquired its currents from feeders 1, 3,
31、 5, 7, 9, 11, and CT1T; whilst 87B2</p><p> acquired from feeders 2, 4, 6, 8, 10, 12, and CT2T.</p><p> Fig. 2. Results with 87B1 for Case 2. (a) Locus of I and I ; (b) 87B1, detector, b
32、locking and trip signals.</p><p> Fig. 2. shows the results obtained with 87B1. As expected for an internal fault, both</p><p> andincrease immediately after fault occurrence and the loc
33、us ofand</p><p> moves upward and enters the operating zone at 24.5 ms, i.e. 87B1 operates 1.6 ms after fault inception. The loci are effectively identical for both the C800 and C40 CTs. In CT1T, saturatio
34、n was detected 7.0 ms after fault inception with a C800 CT and 2.3 ms with a C40 CT. This corresponds to the activation of ‘Blocking’ 5.4 ms after 87B1 with C800 CTs and 0.7 ms after 87B1 with C40 CTs. Consequently, the
35、‘Trip’ decision was activated 1.6 ms after fault inception for both C800 and C40 CTs, i.e. t</p><p> saturation.</p><p> HARDWARE IMPLEMENTATION</p><p> The protection techniques
36、 described in this paper were implemented on a prototype relay based on a TMS320C6701 digital signal processor. The relay was then tested in real-time using data generated by EMTP and replayed using “digital–analogue” co
37、nverters. Fig. 3. shows the configuration of the prototype relay system. The fourteen current signals are passed via 1st order RC filters with a cutoff frequency of 1920 Hz to</p><p> 14-bit A/D converters
38、 operating at a sampling rate of 64 s/c.</p><p> Fig. 3. Configuration of hardware implementation.</p><p> CONCLUSION</p><p> This paper described the design, evaluation and imp
39、lementation of a busbar differential protection relay immune to the effects of CT saturation in a measurement CT. The relay operates in conjunction with a CT saturation detection algorithm that uses a third-difference fu
40、nction to detect the start and end of each saturation period. During saturation a blocking signal is activated, it then remains active until one cycle after the end of saturation. In the relay, a logic system is included
41、 to disc</p><p> saturation is detected. The proposed scheme does not delay the operating time of a relay on an internal fault even when a CT is severely saturated.</p><p> The performance of
42、 the proposed relay was validated under various conditions with C800 (rated) and C40 (measurement) CTs. The saturation detection algorithm successfully detects each saturation period even when a CT is severely saturated
43、due to its small size. Test results indicate that the relay, even when configured with a highly sensitive operating characteristic, re-mains stable during external faults even when a CT is severely saturated. It also det
44、ects internal faults, without any addition</p><p> The proposed relay has a number of significant advantages:</p><p> high stability on external faults with enhanced sensitivity;</p>&l
45、t;p> fast operation on internal faults with CT saturation;</p><p> makes use with measurement type CTs possible;</p><p> minimal computational burden ideal for busbar protection.</p>
46、<p><b> 二、中文翻譯</b></p><p> 適用于測(cè)量型電流互感器的母線差動(dòng)保護(hù)繼電器 </p><p><b> 摘要</b></p><p> 本文介紹了適用于測(cè)量型電流互感器(CT)的母線電流差動(dòng)保護(hù)繼電器的設(shè) 計(jì)、評(píng)估和實(shí)現(xiàn)。繼電器與飽和度檢測(cè)算法一起運(yùn)行,該算法使用基于施加到當(dāng)
47、 前信號(hào)的第三差分函數(shù)的技術(shù)來有效地檢測(cè)每個(gè)飽和周期的開始和結(jié)束。阻塞信 號(hào)在飽和開始后立即激活,并保持有效,直到飽和期加上一個(gè)周期的額外延遲已 超時(shí)。對(duì)于導(dǎo)致 CT 飽和的內(nèi)部故障,繼電器在阻塞信號(hào)被激活之前發(fā)出跳閘命令。 對(duì)于外部故障,導(dǎo)致 CT 飽和,阻塞信號(hào)首先到達(dá),并且跳閘命令保持不動(dòng)。測(cè)試結(jié)果表明,即使當(dāng) CT 中的剩余磁通量較高并且測(cè)量 CT 的故障能力受到嚴(yán)格限制 時(shí),繼電器成功地區(qū)分了內(nèi)部和外部故障。本文最后描述了如何
48、在基于數(shù)字信號(hào) 處理器的原型繼電器上實(shí)現(xiàn)繼電器。與傳統(tǒng)的母線差動(dòng)保護(hù)方案相比,新型繼電 器在外部故障方面實(shí)現(xiàn)了更高的穩(wěn)定性,并提高了內(nèi)部故障的靈敏度。</p><p> 關(guān)鍵詞:閉鎖信號(hào)和剩余通量,母線保護(hù),電流互感器飽和,差分功能,測(cè)量CT。</p><p><b> 第一章 介紹</b></p><p> 大電流外部故障期間電流互感器
49、飽和程度對(duì)母線差動(dòng)保護(hù)方案的影響是非常 重要的。保護(hù)必須保持穩(wěn)定,但為確保此目的而需要的設(shè)置和或操作技術(shù)不得延 遲或防止在低電流內(nèi)部故障下運(yùn)行。母線保護(hù) CT 通常尺寸適合高過電流因素,但 成本和實(shí)際限制意味著在嚴(yán)重外部故障時(shí)不能避免飽和。差分方案中使用的雙斜 率工作特性旨在確保大電流外部故障的穩(wěn)定性。然而,如果工作特性敏感度很高, 則繼電器可能無法檢測(cè)到低電流內(nèi)部故障,特別是當(dāng)通電電流較大時(shí)。因此,替 代解決方案是基于電流互感器飽和度
50、的檢測(cè)和由此導(dǎo)致操作的閉鎖。</p><p> Kumar 和 Hansen 提出了一種母線差動(dòng)繼電器,用于 CT 飽和的對(duì)策。有效地, 只有在初始跳閘決定的 11-14ms 內(nèi)(對(duì)于 50Hz 系統(tǒng)),跳閘信號(hào)才被再次飽和。 雙重測(cè)量技術(shù)可確保外部故障的穩(wěn)定性,但可將內(nèi)部故障的運(yùn)行時(shí)間增加到 25 ms。為了確保高電流內(nèi)部故障的快速響應(yīng),雙重測(cè)量技術(shù)將被忽略,如果在故障 發(fā)生的幾毫秒內(nèi)發(fā)生初始跳閘判定,則立即
51、激活跳閘信號(hào)。該方法有效設(shè)對(duì)于最 壞情況的內(nèi)部故障進(jìn)行了假設(shè),在最初的幾個(gè)毫秒內(nèi)沒有一個(gè) CT 飽和。</p><p> Sachdev et al 提出了一種母線保護(hù)技術(shù),可以估測(cè)連接到母線的每回線的正序 和負(fù)序電路的阻抗。這個(gè)想法類似于相位角比較,即它比較每個(gè)回線中的電流流 動(dòng)方向,因此相對(duì)于基于差分電流的幅度的算法,飽和效應(yīng)的依賴性較小。 如果 每個(gè)回線上看到的所有阻抗都位于阻抗平面的第三個(gè)象限中,則內(nèi)部
52、故障將被消 除。</p><p> 本文介紹了適用于測(cè)量 CT 操作的母線差動(dòng)繼電器的設(shè)計(jì),評(píng)估和實(shí)現(xiàn)。這是</p><p> 使用飽和檢測(cè)算法來實(shí)現(xiàn)的,該算法在 CT 飽和時(shí)阻止繼電器的操作,并且在結(jié)束 之后的一個(gè)周期的周期內(nèi)實(shí)現(xiàn)。通過比較保護(hù)操作信號(hào)和飽和阻塞信號(hào)被激活的 順序來實(shí)現(xiàn)區(qū)分內(nèi)部和外部故障的邏輯。即使 CT 飽和,提出的方案也不會(huì)延遲內(nèi) 部故障繼電器的工作時(shí)間。使用從具
53、有 12 個(gè)饋線的模擬 154 kV 雙母線變電站獲</p><p> 得的采樣率為 64 個(gè)樣本周期的電流來研究繼電器的性能。在研究中使用了兩種類 型的 CT,第一個(gè) C800 保護(hù) CT 適用于應(yīng)用,第二個(gè) C40 測(cè)量 CT。本文通過描述 基于數(shù)字信號(hào)處理器的原型繼電器和使用母線 EMTP 模型生成的數(shù)據(jù)進(jìn)行測(cè)試時(shí)得 到的結(jié)果。</p><p> 第二章 差分繼電器工作與飽和度檢
54、測(cè)算法的合并</p><p> 2.1 CT 飽和度檢測(cè)算法</p><p> 本節(jié)簡(jiǎn)要介紹了 CT 飽和檢測(cè)算法。該算法檢測(cè)次級(jí)電流中與每個(gè)飽和周期的 開始或結(jié)束相對(duì)應(yīng)的拐點(diǎn)。這是使用感測(cè)不連續(xù)性的差分函數(shù)和將這些不連續(xù)性 轉(zhuǎn)換為脈沖的第三差分函數(shù)來實(shí)現(xiàn)的。檢測(cè)算法可以準(zhǔn)確檢測(cè)每個(gè)飽和周期的開 始和結(jié)束,而不考慮剩余通量的水平.該算法具有最小的計(jì)算負(fù)擔(dān),非常適用于母 線保護(hù)方案。&l
55、t;/p><p> 目前包含故障拐點(diǎn)。這會(huì)導(dǎo)致第三個(gè)差異函數(shù)中的初始峰值,這可能會(huì)被錯(cuò) 誤地檢測(cè)為飽和開始。防止誤操作,僅當(dāng)兩個(gè)連續(xù)樣本的電流信號(hào)超過額定電流 的兩倍時(shí),才使用這個(gè)算法。</p><p> 2.2 差分繼電器運(yùn)行飽和度檢測(cè)算法</p><p> 在每個(gè)飽和周期開始時(shí),“閉鎖”信號(hào)被激活,并保持到飽和周期加上另外 一個(gè)周期周期結(jié)束。需要額外的延時(shí),因
56、為 DFT 窗口保持大的差分電流值,直到 飽和結(jié)束后一個(gè)周期; 因此,繼電器的軌跡繼續(xù)保持在操作區(qū)域。 如果 CT 飽和, 則“內(nèi)部故障”也將被激活,但是由于后面描述的邏輯可以可靠地消除內(nèi)部和外 部故障之間的錯(cuò)誤,因此現(xiàn)在會(huì)發(fā)出“跳閘”信號(hào)。</p><p><b> 第三章 實(shí)例探究</b></p><p> 圖 1 是韓國(guó)具有 12 回線的典型 154kV 雙
57、母線系統(tǒng)的單線圖。 回線 1,3,5,7,9</p><p> 和 11 連接到總線 1 和回線 2,4,6,8,10 和 12 連接到總線 2.兩個(gè)母線與總線耦合器連 接。對(duì)于案例研究,選擇了兩種 CT:額定保護(hù) CT(用于所有韓國(guó) 154 kV 母線) 和測(cè)量 CT。根據(jù)使用 EMTP 描述的方法對(duì) CT 進(jìn)行建模,模擬了通電時(shí)的核心的 剩余通量。</p><p> 圖 1 模擬系
58、統(tǒng)的單線圖</p><p> 每個(gè) CT 連接到 3.42 的電阻負(fù)載,每個(gè) CT 的飽和點(diǎn)選擇為 5.12A,對(duì)于 C800 為 2.9 秒,對(duì)于 C40,0.15 秒為 2.05A。 然后由 EMYS 中的輔助程序 HYSDAT 使 用,產(chǎn)生滯后數(shù)據(jù)。</p><p> 電流信號(hào)通過具有 1920Hz 截止頻率的阻抗混疊 1 階 RC 低通濾波器,然后以</p>&l
59、t;p> 64s / c(3840Hz,60Hz)采樣。</p><p> 差分繼電器 87B1 和 87B2 分別用于保護(hù)總線 1 和總線 2 。 87B1 從饋線</p><p> 1,3,5,7,9,11 和 CT1T 獲取電流; 而 87B2 則從飼料 2,4,6,8,10,12 和 CT2T 獲得。</p><p> 圖 2. 87B1 結(jié)果
60、。(a)I 和 I 的軌跡; (b)87B1,檢測(cè)器,阻塞和跳閘信號(hào)。</p><p> 圖 2 顯示用 87B1 獲得的結(jié)果。如預(yù)期的內(nèi)部故障,兩者都在故障發(fā)生后立即 增加,軌跡向上移動(dòng)并使操作區(qū)在 24.5 ms,即 87B1 在故障開始后運(yùn)行 1.6 ms。 對(duì) 于 C800 和 C40 CT,軌跡都是相同的。 在 CT1T 中,使用 C800 CT 檢測(cè)出故障后 7.0 毫秒,C40 CT 檢測(cè)到飽和度
61、 2.3 毫秒。這對(duì)應(yīng)于在 87B1 與 C800CT 之間 5.4ms 的“阻塞”激活,在具有 C40CT 的 87B1 之后激活“0.7ms”。因此,在 C800 和 C40 CT 故障發(fā)生后,“Trip”決定被激活 1.6 ms,即繼電器正確檢測(cè)到內(nèi)部故障,并且跳閘 決定不會(huì)被 CT 飽和的影響延遲。</p><p><b> 第四章 硬件實(shí)施</b></p><
62、p> 本文介紹的保護(hù)技術(shù)是基于 TMS320C6701 數(shù)字信號(hào)處理器的原型繼電器實(shí) 現(xiàn)的。 然后使用 EMTP 生成的數(shù)據(jù)實(shí)時(shí)測(cè)試?yán)^電器,并使用“數(shù)模轉(zhuǎn)換器”重播。 圖 3 顯示原型繼電器系統(tǒng)的配置。十四個(gè)電流信號(hào)通過具有 1920Hz 截止頻率的第 一級(jí) RC 濾波器通過以 64s / c 的采樣率工作的 14 位 A / D 轉(zhuǎn)換器。</p><p> 圖 3 配置硬件實(shí)現(xiàn)圖</p>
63、<p><b> 第五章 結(jié)論</b></p><p> 本文介紹了在測(cè)量 CT 中免疫 CT 飽和效應(yīng)的母線差動(dòng)保護(hù)繼電器的設(shè)計(jì),評(píng) 估和實(shí)現(xiàn)。繼電器與 CT 飽和檢測(cè)算法一起運(yùn)行,該算法使用第三差函數(shù)來檢測(cè)每 個(gè)飽和周期的開始和結(jié)束。在飽和狀態(tài)下,阻塞信號(hào)被激活,然后在飽和結(jié)束后 一個(gè)周期保持有效。在繼電器中,包括一個(gè)邏輯系統(tǒng)來區(qū)分內(nèi)部和外部故障。這 通過將保護(hù)操作信號(hào)與
64、飽和檢測(cè)器阻塞信號(hào)進(jìn)行比較來完成。在外部故障期間, 繼電器保持穩(wěn)定,因?yàn)樵诒Wo(hù)動(dòng)作之前接收到阻塞信號(hào)。在內(nèi)部故障期間,由于 保護(hù)繼電器在檢測(cè)到飽和之前運(yùn)行,因此發(fā)出跳閘命令。所提出的方案即使在 CT 嚴(yán)重飽和時(shí)也不會(huì)延遲繼電器在內(nèi)部故障時(shí)的工作時(shí)間。</p><p> 對(duì)于所提出的繼電器的性能在各種條件下使用 C800(額定)和 C40(測(cè)量) CT 進(jìn)行了驗(yàn)證。飽和檢測(cè)算法成功地檢測(cè)每個(gè)飽和周期,即使 CT
65、由于其小尺寸 而嚴(yán)重飽和。測(cè)試結(jié)果表明,即使配置了高度敏感的工作特性,繼電器即使在 CT</p><p> 嚴(yán)重飽和時(shí)也能在外部故障期間穩(wěn)定。 即使 CT 嚴(yán)重飽和,也可以檢測(cè)內(nèi)部故障, 無任何額外的運(yùn)行時(shí)間延遲。基于所述方案的原型繼電器在涉及 CT 飽和的各種操 作場(chǎng)景下成功地區(qū)分了內(nèi)部和外部故障。 繼電器的采樣速率為 64 s / c。</p><p> 所提出的繼電器具有很多顯著
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