在我國(guó),中、低壓母線短路故障中,重點(diǎn)設(shè)備和人員傷害主要由電弧光引起,然而,我國(guó)的大多數(shù)中低壓母線沒(méi)有設(shè)置快速母線保護(hù),而只是采用了簡(jiǎn)單的消弧裝置和變壓器后備保護(hù)。這些保護(hù)智能化較低,動(dòng)作速度慢,往往會(huì)延長(zhǎng)故障切除時(shí)間,從而進(jìn)一步擴(kuò)大設(shè)備損壞程度,甚至?xí)稹盎馃B營(yíng)”的惡性事故,沖擊變壓器一次運(yùn)行,影響整個(gè)電網(wǎng)的安全運(yùn)行。
弧光保護(hù)系統(tǒng)是我公司根據(jù)國(guó)內(nèi)實(shí)際情況,吸收國(guó)外電弧光保護(hù)的特點(diǎn),結(jié)合行業(yè)檢測(cè)及保護(hù)配置相關(guān)規(guī)程,自主研發(fā)出具有獨(dú)特創(chuàng)新技術(shù)、具有廣泛實(shí)用性、高可靠性的新型電弧光保護(hù)系統(tǒng)。采用弧光檢測(cè)和過(guò)電流檢測(cè)雙判據(jù)原理,具有保護(hù)動(dòng)作速度快、可靠性高等特點(diǎn)。
引起開(kāi)關(guān)柜弧光短路故障的原因很多,一般分為以下五類。
1)絕緣故障:主要是柜中絕緣材料爬距不足,未滿足加強(qiáng)絕緣要求,在臟污環(huán)境,天氣潮濕下發(fā)生絕緣故障。另外,由于絕緣材料材質(zhì)缺陷,運(yùn)行年限較長(zhǎng)的開(kāi)關(guān)柜,在強(qiáng)電磁場(chǎng)作用下絕緣老化,也可能造成絕緣損壞而導(dǎo)致故障。
2)載流回路不良:由于一些接頭截面不夠,緊固螺栓松動(dòng),手車柜觸頭接觸不良,在大電流流過(guò)時(shí)引起發(fā)熱,冒火進(jìn)而引起相間,相對(duì)地?fù)舸┑鹊取?/p>
3)外來(lái)物體的進(jìn)入:如小動(dòng)物(老鼠等)進(jìn)入開(kāi)關(guān)柜內(nèi)部,或維修人員在工作完成后將工具遺留在開(kāi)關(guān)柜內(nèi)。
4)認(rèn)為操作錯(cuò)誤:如走錯(cuò)間隔,誤操作,未對(duì)工作區(qū)域進(jìn)行接地,未對(duì)工作區(qū)域進(jìn)行驗(yàn)電等。
5)系統(tǒng)方面的原因:如系統(tǒng)容量增大,接地方式改變,電纜應(yīng)用增多,保護(hù)及自控裝置配置不當(dāng),系統(tǒng)諧振過(guò)電壓等。
開(kāi)關(guān)柜內(nèi)的發(fā)生短路弧光的功率可高達(dá)100MW,電弧燃燒所產(chǎn)生的能量與電弧的燃燒時(shí)間及短路電流變化值呈指數(shù)倍增長(zhǎng)(如下圖所示),燃燒產(chǎn)生的高溫、高壓將會(huì)逐步摧毀元器件、銅排以及成列的開(kāi)關(guān)柜,高明亮的弧光和有毒氣體對(duì)人體也有巨大的傷害。


要保證設(shè)備不受結(jié)構(gòu)性損傷,必須盡量縮短切除時(shí)間。
以下為國(guó)外資料介紹的各種燃弧時(shí)間長(zhǎng)短和對(duì)設(shè)備造成的損壞程度的評(píng)估:

電弧光保護(hù)系統(tǒng),可以起到以下作用:
The Arc protection system functions as follows:
1) 減少或降低電弧光對(duì)于人體的傷害;
1) Reduce or decrease the harms of Arc to human body;
2) 減少或降低電弧光短路故障對(duì)于設(shè)備的損害;
2) Reduce or decrease the damage of Arc short circuit fault to the equipment;
3) 避免變壓器因近距離母線故障造成動(dòng)穩(wěn)定破壞,延長(zhǎng)變壓器的使用壽命;
3) Avoid the dynamic stability damage caused by the close range busbar fault of transformer and extend the service life of the transformer;
4) 縮短電弧光故障切除時(shí)間,避免波及站內(nèi)直流系統(tǒng)造成重大損失;
4) Shorten the Arc fault clearing time to avoid significant losses caused by the DC system in the station;
5) 減少因電弧光故障造成設(shè)備停運(yùn)的時(shí)間,更快地恢復(fù)供電;
5) Reduce the equipment shutdown time caused by the Arc fault and restore the power more quickly;
1) 電力變電站
1) Power substation
2) 常規(guī)電氣段開(kāi)關(guān)柜
2) Switch cabinet of conventional electrical section power plant
3)風(fēng)電場(chǎng)升壓站集電線路開(kāi)關(guān)柜
3) Collector line switchgear of booster station of wind farm
4)箱式變電站
4) Box substation
1).動(dòng)作迅速可靠:
1). Rapid and reliable motion:
采用了可靠的快速算法,可以在短時(shí)間內(nèi)判斷弧光變化信號(hào)和電流變化信號(hào)并迅速出口,從發(fā)現(xiàn)故障到出口跳閘時(shí)間間隔優(yōu)于10ms,確保開(kāi)關(guān)柜內(nèi)設(shè)備的弧光在75ms以內(nèi)切除。
By adopting the reliable fast algorithm, the Arc and current change signals can be judged and rapidly sent to the outlet in a short time. The time interval from discovering the fault to tripping at the outlet is shorter than 10ms so as to ensure that the Arc in the switchgear can be removed within 75ms.
2).全數(shù)字化設(shè)計(jì):
2). Complete digital design:
本裝置采用全數(shù)字化設(shè)計(jì),配置靈活,動(dòng)作精度高,而且排除了由于旋鈕或其他機(jī)械設(shè)計(jì)導(dǎo)致的誤差隱患。
The device adopts complete digital design which is characterized by flexible configuration and high motion precision and excludes the hidden trouble of errors caused by the knob or other mechanical design.
3).原理簡(jiǎn)單
3).Simple principle
根據(jù)弧光產(chǎn)生時(shí)的特點(diǎn),裝置采用弧光和電流雙重判據(jù),判據(jù)簡(jiǎn)單且可以有效的保證動(dòng)作的準(zhǔn)確性。
The device adopts the double criterion of Arc and current according to the characteristics when the Arc is generated. The criteria are simple and can effectively ensure the accuracy of motion.
4).強(qiáng)大的電氣性能:
4). Strong electrical performance:
弧光探頭設(shè)計(jì)、連接線等全部采用耐高溫、阻燃的高分子材料,具有超強(qiáng)的電氣隔離效果。裝置完全滿足EMC的標(biāo)準(zhǔn),保證了弧光保護(hù)系統(tǒng)的整體穩(wěn)定性和動(dòng)作的可靠性。
The Arc probe and connecting wire are made from heat-resistant and flame-retardant polymer materials which have superior electrical isolation effect. The device completely meets the EMC standard and ensures the overall stability of the Arc protection system as well as motion reliability.
5).故障信息記錄全面
5). Comprehensive record of fault information
在故障弧光發(fā)生并引起裝置跳閘后,主控單元或饋線保護(hù)單元可以準(zhǔn)確的記錄弧光探頭檢測(cè)到故障弧光的位置信息,且可以詳細(xì)記錄動(dòng)作時(shí)刻的三相電流值。
After fault Arc occurs and causes tripping, the main control unit or feeder protection unit can record the location information of the fault Arc detected by the Arc probe accurately and record the three-phase current value at the moment of motion in details.
弧光保護(hù)系統(tǒng)主要由主控單元、弧光采集單元和弧光傳感器組成,為了適應(yīng)現(xiàn)場(chǎng)的應(yīng)用需求,分為了母線型弧光保護(hù)系統(tǒng)和饋線型弧光保護(hù)系統(tǒng)。
The Arc protection system is mainly composed of the main control unit, the Arc acquisition unit and the Arc sensor. In order to meet the field application requirements, it is divided into bus Arc protection system and feeder Arc protection system.
2.2.1 主控單元
2.2.1 Main control unit
主控單元是母線型弧光保護(hù)系統(tǒng)的核心。它檢測(cè)分析故障信號(hào)、接收分析采集單元的弧光故障信號(hào),并對(duì)兩種信號(hào)進(jìn)行綜合分析判斷。在滿足跳閘條件時(shí),發(fā)出跳閘指令以切除故障。主控單元一般安裝在進(jìn)線柜或緊鄰進(jìn)線柜的開(kāi)關(guān)柜的二次控制門板上。
The main control unit is the core of the bus Arc protection system. It detects and analyzes the fault signal, receives and analyzes the Arc fault signal of the acquisition unit, and makes the comprehensive analysis and judgment of the two signals. When the tripping condition is satisfied, it issues the trip instruction to remove the fault.The main control unit is usually installed on the secondary control panel of the access cabinet or the switch cabinet near the access cabinet.
主控單元具備如下特點(diǎn):
The main control unit has the following characteristics:
1)48個(gè)弧光信號(hào)檢測(cè)接口,用于接收來(lái)自弧光傳感器的弧光故障信號(hào);
1) There are 48 Arc signal detection interfaces that are used to receive Arc fault signals from Arc sensors.
2)2個(gè)數(shù)據(jù)通訊接口,1路RS485,1路以太網(wǎng);
2) There are 2 data communication interfaces, 1-route RS485, 1-route Ethernet.
3)4路快速跳閘輸出接口,符合IEC255-23繼電器標(biāo)準(zhǔn)。
3) There are 4-route fast tripping output interfaces that conform to the IEC255-23 relay standard.
4)2路報(bào)警出口,其中一路為裝置故障出口。
4) There are 2 alarm outlets, one of which is the device fault outlet
5)12路電流輸入,檢測(cè)4組三相電流信號(hào),用于判斷故障電流。
5) There are 12-route current input that detects 4 groups of three-phase current signals and judges the fault current.
2.2.2 弧光傳感器
2.2.2 Arc sensor
弧光傳感器中的探頭安裝在柜內(nèi)各間隔中,可實(shí)現(xiàn)由簡(jiǎn)單到復(fù)雜、有選擇性的保護(hù)?;」馓筋^作為光感應(yīng)元件,在發(fā)生弧光故障時(shí)檢測(cè)突然增加的光強(qiáng)。
The probe in the Arc sensor is installed in each interval of the cabinet, which can realize the selective protection from simple to complex. The Arc sensor is used as a light sensing element to detect sudden increase of light intensity when Arc failure occurs.
光纖式弧光傳感器,前置探頭采集弧光信號(hào)中的特有光譜信息,并通過(guò)專用光纖將光信號(hào)傳送給弧光采集單元或主控單元,弧光單元或主控單元完成光信號(hào)的分析處理與采集。
The pre-probe of optical fiber type Arc sensor collects the special spectral information of Arc signal, and transmits the optical signal to the Arc acquisition unit or the main control unit through the special optical fiber, and the Arc unit or the main control unit completes the analysis, processing and acquisition of the optical signal.
本系統(tǒng)具有以下技術(shù)特點(diǎn):
The system has the following technical characteristics:
1)滿足所有電磁兼容(EMC)標(biāo)準(zhǔn);
1) It satisfies all electromagnetic compatibility (EMC) standards;
2) 符合中國(guó)繼電保護(hù)設(shè)計(jì)標(biāo)準(zhǔn)要求;
2) It conforms to the requirements of China's relay protection design standards;
3) 采用過(guò)流及弧光雙重判據(jù),可靠性高;
3) It adopts the double criterion of over-current and Arc, with high reliability.
4) 新型光纖連接傳輸,光電轉(zhuǎn)換在裝置內(nèi)完成,抗電磁干擾能力強(qiáng);
4) It is connected and transmits with new optical fiber, and photoelectric conversion is completed in the device, with strong electromagnetic interference resistance;
5) 采用過(guò)濾干擾光的新型弧光傳感器,具有過(guò)濾干擾光的功能,避免可見(jiàn)光傳感器受環(huán)境光照影響引起誤動(dòng);
5) It adopts a new type of Arc sensor to filter the interference light to filter the interference light, and avoid the visible light sensor mal-operation caused by the influence of ambient light.
6)出口跳閘時(shí)間小于10ms,遠(yuǎn)快于傳統(tǒng)的母線保護(hù),對(duì)開(kāi)關(guān)柜的內(nèi)部弧光故障總切除時(shí)間可以控制在75ms以內(nèi);
6) Outlet tripping time is less than 10ms, which is much faster than traditional bus protection. The total removal time of internal Arc faults of switch cabinet can be controlled within 75ms.
7)全漢字(英文)顯示,操作習(xí)慣和傳統(tǒng)數(shù)字式保護(hù)完全一致;
7) It is displayed with full Chinese(English)characters, and operation habits are identical with traditional digital protection.
8) The logic of trip exit is programmable.
主控單元采用全封閉4U 1/2標(biāo)準(zhǔn)機(jī)箱,嵌入式安裝于屏(柜)上。插件為后插導(dǎo)軌式,插緊后上下有鎖緊螺絲。機(jī)箱安裝開(kāi)孔尺寸圖如下:
The main control unit adopts the fully enclosed 4U 1/2 standard case, and is mounted on the screen (cabinet). The plug-in is a rear-insert guide rail with tight screws up and down. The size of the mounting holes is as follows: