0 引 言
繼電(dian)保護對(dui)變電(dian)站設(she)備(bei)(bei)的(de)(de)安全運行(xing)起(qi)著(zhu)至(zhi)關重要(yao)的(de)(de)保障(zhang)作(zuo)用(yong),在電(dian)氣設(she)備(bei)(bei)發生故(gu)(gu)障(zhang)或工作(zuo)異常時,能夠自(zi)動、快速(su)、有(you)選擇地將故(gu)(gu)障(zhang)設(she)備(bei)(bei)從系統中(zhong)切除,將事故(gu)(gu)限制在*小范(fan)圍內,提高系統運行(xing)可(ke)(ke)靠性。可(ke)(ke)靠、高效的(de)(de)繼電(dian)保護技術對(dui)于變電(dian)站和(he)電(dian)力系統的(de)(de)安全可(ke)(ke)靠運行(xing)具有(you)非常重要(yao)的(de)(de)意義[1-3]。
目前,繼(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)保(bao)(bao)(bao)(bao)護(hu)(hu)技術在(zai)常規變(bian)(bian)(bian)(bian)電(dian)(dian)(dian)(dian)(dian)(dian)站(zhan)的應用中(zhong)(zhong)已經顯得尤為(wei)成熟(shu)、穩定(ding),而正在(zai)新建的智(zhi)能(neng)變(bian)(bian)(bian)(bian)電(dian)(dian)(dian)(dian)(dian)(dian)站(zhan)相較常規變(bian)(bian)(bian)(bian)電(dian)(dian)(dian)(dian)(dian)(dian)站(zhan),對繼(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)保(bao)(bao)(bao)(bao)護(hu)(hu)技術的要(yao)求(qiu)更為(wei)嚴格。智(zhi)能(neng)變(bian)(bian)(bian)(bian)電(dian)(dian)(dian)(dian)(dian)(dian)站(zhan)在(zai)繼(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)保(bao)(bao)(bao)(bao)護(hu)(hu)技術方(fang)面存(cun)在(zai)采樣(yang)數(shu)(shu)據(ju)(ju)(ju)網絡(luo)傳(chuan)輸(shu)(shu)和(he)(he)以太網傳(chuan)輸(shu)(shu)延(yan)遲的不(bu)確定(ding)性[4-5]的問題,因此,研究如何進一(yi)步(bu)(bu)提(ti)高(gao)智(zhi)能(neng)變(bian)(bian)(bian)(bian)電(dian)(dian)(dian)(dian)(dian)(dian)站(zhan)數(shu)(shu)據(ju)(ju)(ju)采集的同(tong)(tong)步(bu)(bu)性,消除差異性傳(chuan)輸(shu)(shu)與延(yan)遲帶(dai)來的影(ying)響至(zhi)關重要(yao)。文(wen)獻(xian)[6-7]提(ti)出用于繼(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)保(bao)(bao)(bao)(bao)護(hu)(hu)中(zhong)(zhong)合(he)并單元的高(gao)采樣(yang)率(lv)數(shu)(shu)據(ju)(ju)(ju)的方(fang)案,能(neng)有效識別準確的數(shu)(shu)據(ju)(ju)(ju)采樣(yang)時間(jian)是智(zhi)能(neng)變(bian)(bian)(bian)(bian)電(dian)(dian)(dian)(dian)(dian)(dian)站(zhan)間(jian)隔層和(he)(he)過程(cheng)層智(zhi)能(neng)電(dian)(dian)(dian)(dian)(dian)(dian)子設(she)(she)(she)備(intelligent electronic device,IED)之間(jian)數(shu)(shu)據(ju)(ju)(ju)同(tong)(tong)步(bu)(bu)的關鍵,這在(zai)很(hen)大(da)程(cheng)度上(shang)制(zhi)約了(le)智(zhi)能(neng)變(bian)(bian)(bian)(bian)電(dian)(dian)(dian)(dian)(dian)(dian)站(zhan)繼(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)保(bao)(bao)(bao)(bao)護(hu)(hu)網絡(luo)的應用。數(shu)(shu)字式(shi)繼(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)保(bao)(bao)(bao)(bao)護(hu)(hu)測試(shi)(shi)儀是目前應用*廣泛的調試(shi)(shi)工(gong)具,數(shu)(shu)字式(shi)繼(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)保(bao)(bao)(bao)(bao)護(hu)(hu)測試(shi)(shi)儀基(ji)本能(neng)滿足智(zhi)能(neng)變(bian)(bian)(bian)(bian)電(dian)(dian)(dian)(dian)(dian)(dian)站(zhan)保(bao)(bao)(bao)(bao)護(hu)(hu)裝(zhuang)(zhuang)置(zhi)測試(shi)(shi)的要(yao)求(qiu),但在(zai)測試(shi)(shi)過程(cheng)中(zhong)(zhong)仍需(xu)要(yao)大(da)量的人工(gong)操作[8-9]。現(xian)有測試(shi)(shi)儀存(cun)在(zai)以下缺(que)陷:繼(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)保(bao)(bao)(bao)(bao)護(hu)(hu)測試(shi)(shi)儀不(bu)能(neng)實現(xian)對所有保(bao)(bao)(bao)(bao)護(hu)(hu)裝(zhuang)(zhuang)置(zhi)的遠程(cheng)控制(zhi);繼(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)保(bao)(bao)(bao)(bao)護(hu)(hu)測試(shi)(shi)儀不(bu)能(neng)自(zi)動(dong)(dong)設(she)(she)(she)置(zhi)故障參數(shu)(shu)(substation configuration description,SCD)文(wen)件(jian)后,繼(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)保(bao)(bao)(bao)(bao)護(hu)(hu)測試(shi)(shi)儀無法檢查(cha)保(bao)(bao)(bao)(bao)護(hu)(hu)裝(zhuang)(zhuang)置(zhi)的一(yi)致(zhi)性和(he)(he)測試(shi)(shi)儀配置(zhi)信息的一(yi)致(zhi)性。因此,根據(ju)(ju)(ju)目前廠(chang)站(zhan)側(ce)保(bao)(bao)(bao)(bao)護(hu)(hu)裝(zhuang)(zhuang)置(zhi)的特點,開發了(le)一(yi)種針對智(zhi)能(neng)變(bian)(bian)(bian)(bian)電(dian)(dian)(dian)(dian)(dian)(dian)站(zhan)保(bao)(bao)(bao)(bao)護(hu)(hu)裝(zhuang)(zhuang)置(zhi)的自(zi)動(dong)(dong)測試(shi)(shi)系(xi)統(tong),其中(zhong)(zhong)包括測試(shi)(shi)系(xi)統(tong)的軟硬件(jian)結構設(she)(she)(she)計(ji)。采用模塊化設(she)(she)(she)計(ji)思想,旨在(zai)提(ti)高(gao)系(xi)統(tong)的可擴展性,同(tong)(tong)時支持(chi)多設(she)(she)(she)備同(tong)(tong)步(bu)(bu)自(zi)動(dong)(dong)測試(shi)(shi)功能(neng),進一(yi)步(bu)(bu)提(ti)高(gao)測試(shi)(shi)效率(lv)。
1 系統(tong)測試方法設計
測(ce)試(shi)系統由保護測(ce)試(shi)主站通(tong)過(guo)智(zhi)(zhi)能變(bian)電(dian)站后備(bei)光纖控制多臺分布式(shi)信(xin)(xin)號(hao)發生(sheng)器(qi)同步(bu)測(ce)試(shi)和現場(chang)智(zhi)(zhi)能終端(duan)動作反饋來完成(cheng)測(ce)試(shi)參(can)數配置(zhi)和測(ce)試(shi)過(guo)程控制。如(ru)圖1所示的測(ce)試(shi)系統結構包(bao)括(kuo)采集單元、測(ce)量(liang)接(jie)口(kou)(kou)裝置(zhi)、制造報文規范(manufacturing message specification,MMS)信(xin)(xin)號(hao)接(jie)口(kou)(kou)模(mo)塊(kuai)、面向通(tong)用對象的變(bian)電(dian)站事件(generic object oriented substation event,GOOSE)信(xin)(xin)號(hao)接(jie)口(kou)(kou)模(mo)塊(kuai)、分布式(shi)信(xin)(xin)號(hao)發生(sheng)器(qi)接(jie)口(kou)(kou)模(mo)塊(kuai)、時(shi)間信(xin)(xin)號(hao)接(jie)口(kou)(kou)模(mo)塊(kuai)、時(shi)鐘同步(bu)模(mo)塊(kuai)、測(ce)試(shi)控制模(mo)塊(kuai)等(deng)。
保護系統信息(xi)管理主站可獲取繼電保護設置表(biao),配(pei)置繼電保護測試(shi)參數(shu)表(biao),設置分布式信號發(fa)生器和信號輸出接(jie)口的(de)間隔,控制自動測試(shi)過程(cheng);接(jie)收繼電保護動作信號,顯示*終測試(shi)結果,獲取智能變電站SCD文(wen)件等(deng)。
MMS 信(xin)(xin)(xin)號(hao)(hao)接(jie)口(kou)(kou)模(mo)塊用(yong)于(yu)(yu)接(jie)入(ru)(ru)繼(ji)電(dian)(dian)(dian)保(bao)護(hu)(hu) MMS網(wang)(wang)絡,獲(huo)取(qu)繼(ji)電(dian)(dian)(dian)保(bao)護(hu)(hu)整(zheng)定策(ce)略(lve)表,與人(ren)機(ji)交(jiao)(jiao)互界(jie)面獲(huo)取(qu)的(de)繼(ji)電(dian)(dian)(dian)保(bao)護(hu)(hu)整(zheng)定策(ce)略(lve)表進行比對(dui),完成繼(ji)電(dian)(dian)(dian)保(bao)護(hu)(hu)裝置校準(zhun)(zhun)(zhun)比對(dui)。GOOSE 信(xin)(xin)(xin)號(hao)(hao)接(jie)口(kou)(kou)模(mo)塊用(yong)于(yu)(yu)訪問繼(ji)電(dian)(dian)(dian)保(bao)護(hu)(hu)GOOSE網(wang)(wang)口(kou)(kou),獲(huo)取(qu)繼(ji)電(dian)(dian)(dian)保(bao)護(hu)(hu)動作信(xin)(xin)(xin)息(xi)[10]。分(fen)布(bu)(bu)式(shi)信(xin)(xin)(xin)號(hao)(hao)發生(sheng)(sheng)器(qi)接(jie)口(kou)(kou)模(mo)塊為 3~4路光(guang)以(yi)太(tai)網(wang)(wang)接(jie)口(kou)(kou),通過(guo)現場(chang)備用(yong)光(guang)纖(xian)接(jie)入(ru)(ru)分(fen)布(bu)(bu)式(shi)信(xin)(xin)(xin)號(hao)(hao)發生(sheng)(sheng)器(qi)進行信(xin)(xin)(xin)號(hao)(hao)交(jiao)(jiao)互。計時(shi)(shi)接(jie)口(kou)(kou)模(mo)塊是(shi)指接(jie)入(ru)(ru)智能變電(dian)(dian)(dian)站計時(shi)(shi)到控制(zhi)終端計時(shi)(shi)。時(shi)(shi)鐘同(tong)步(bu)模(mo)塊用(yong)于(yu)(yu)同(tong)步(bu)外部時(shi)(shi)間(jian),形成信(xin)(xin)(xin)息(xi)管理端的(de)準(zhun)(zhun)(zhun)確(que)對(dui)時(shi)(shi),可標記從GOOSE信(xin)(xin)(xin)號(hao)(hao)接(jie)口(kou)(kou)獲(huo)取(qu)的(de)繼(ji)電(dian)(dian)(dian)保(bao)護(hu)(hu)動作的(de)準(zhun)(zhun)(zhun)確(que)時(shi)(shi)間(jian)[11]。測試控制(zhi)模(mo)塊用(yong)于(yu)(yu)連接(jie) MMS信(xin)(xin)(xin)號(hao)(hao)接(jie)口(kou)(kou)、GOOSE 信(xin)(xin)(xin)號(hao)(hao)接(jie)口(kou)(kou)、分(fen)布(bu)(bu)式(shi)信(xin)(xin)(xin)號(hao)(hao)發生(sheng)(sheng)器(qi)接(jie)口(kou)(kou)、時(shi)(shi)鐘同(tong)步(bu)模(mo)塊和人(ren)機(ji)交(jiao)(jiao)互模(mo)塊,實現繼(ji)電(dian)(dian)(dian)保(bao)護(hu)(hu)總動測試功(gong)能。
2 系統測試方法關鍵技術
2.1 分布(bu)式信號(hao)發生器同步技術
分布式信(xin)號發生(sheng)器的功能如下:
1)發送 FT3格式的 SV(sample value, SV)信號(hao)(hao)和 IEC61850-9-2 格式的 SV 信號(hao)(hao)[12],應用于(yu)模擬總線(xian)電(dian)壓合并單元(yuan)(merging unit, MU)輸出信號(hao)(hao)至(zhi)間隔層MU;
2)接收IRIG-B碼/PPS時間(jian)脈沖,同步后輸(shu)出至合并單(dan)元(yuan);
3)將現(xian)場(chang)動(dong)作反饋信息、測試信號輸出信息、繼電保護(hu)(hu)動(dong)作信息傳(chuan)輸至(zhi)保護(hu)(hu)系統管理(li)主站。
分布式信號(hao)發生器由 FT3信號(hao)接(jie)口(kou)模(mo)塊(kuai)(kuai)、SV信號(hao)接(jie)口(kou)模(mo)塊(kuai)(kuai)、控制(zhi)端接(jie)口(kou)模(mo)塊(kuai)(kuai)、信號(hao)處理模(mo)塊(kuai)(kuai)、時(shi)(shi)鐘信號(hao)接(jie)口(kou)模(mo)塊(kuai)(kuai)、時(shi)(shi)間脈沖接(jie)口(kou)模(mo)塊(kuai)(kuai)、時(shi)(shi)間同步模(mo)塊(kuai)(kuai)、現場動作反饋模(mo)塊(kuai)(kuai)、D/A模(mo)塊(kuai)(kuai)、電(dian)壓(ya)功放模(mo)塊(kuai)(kuai)和電(dian)流(liu)功率放大器模(mo)塊(kuai)(kuai)組(zu)成。其(qi)結構如圖2所示。
FT3信(xin)(xin)(xin)號(hao)(hao)(hao)(hao)接(jie)(jie)口(kou)(kou)模(mo)(mo)塊(kuai)(kuai)用(yong)于(yu)發(fa)(fa)送(song)FT3格式(shi)的SV信(xin)(xin)(xin)號(hao)(hao)(hao)(hao)和傳(chuan)輸(shu)級聯到間隔合并單(dan)元的 SV 信(xin)(xin)(xin)號(hao)(hao)(hao)(hao)。控制端接(jie)(jie)口(kou)(kou)模(mo)(mo)塊(kuai)(kuai)通過現(xian)場備用(yong)光纖與控制端連接(jie)(jie),并進行信(xin)(xin)(xin)號(hao)(hao)(hao)(hao)交(jiao)換。時鐘信(xin)(xin)(xin)號(hao)(hao)(hao)(hao)接(jie)(jie)口(kou)(kou)模(mo)(mo)塊(kuai)(kuai)用(yong)于(yu)將IRIG-B碼(ma)/PPS脈(mo)沖(chong)信(xin)(xin)(xin)號(hao)(hao)(hao)(hao)接(jie)(jie)入分(fen)布(bu)式(shi)信(xin)(xin)(xin)號(hao)(hao)(hao)(hao)發(fa)(fa)生(sheng)器(qi)(qi)。時間信(xin)(xin)(xin)號(hao)(hao)(hao)(hao)接(jie)(jie)口(kou)(kou)模(mo)(mo)塊(kuai)(kuai)用(yong)于(yu)向合并單(dan)元輸(shu)出(chu)準確的時間同(tong)步信(xin)(xin)(xin) 號(hao)(hao)(hao)(hao) IRIG-B 碼(ma)/PPS 脈(mo) 沖(chong) ,當 信(xin)(xin)(xin) 號(hao)(hao)(hao)(hao) 接(jie)(jie) 口(kou)(kou) 模(mo)(mo) 塊(kuai)(kuai) 將IRIG-B 碼(ma)/PPS 脈(mo)沖(chong)時間信(xin)(xin)(xin)號(hao)(hao)(hao)(hao)發(fa)(fa)送(song)至分(fen)布(bu)式(shi)信(xin)(xin)(xin)號(hao)(hao)(hao)(hao)發(fa)(fa)生(sheng)器(qi)(qi)時,同(tong)步IRIG-B碼(ma)/PPS脈(mo)沖(chong)信(xin)(xin)(xin)號(hao)(hao)(hao)(hao)通過時鐘信(xin)(xin)(xin)號(hao)(hao)(hao)(hao)接(jie)(jie)口(kou)(kou)模(mo)(mo)塊(kuai)(kuai)輸(shu)出(chu)至合并單(dan)元。時鐘同(tong)步模(mo)(mo)塊(kuai)(kuai)用(yong)于(yu)同(tong)步外部時間信(xin)(xin)(xin)號(hao)(hao)(hao)(hao),與分(fen)布(bu)式(shi)信(xin)(xin)(xin)號(hao)(hao)(hao)(hao)發(fa)(fa)生(sheng)器(qi)(qi)形成同(tong)步時間。現(xian)場動(dong)作(zuo)反(fan)(fan)饋模(mo)(mo)塊(kuai)(kuai)訪問智能終端動(dong)作(zuo)觸點(dian)(dian)或開關位置(zhi)觸點(dian)(dian),獲(huo)取現(xian)場動(dong)作(zuo)反(fan)(fan)饋信(xin)(xin)(xin)息。
D/A模(mo)(mo)塊(kuai)(kuai)(kuai)將信(xin)(xin)號(hao)(hao)處理(li)模(mo)(mo)塊(kuai)(kuai)(kuai)輸(shu)(shu)出(chu)的數(shu)字信(xin)(xin)號(hao)(hao)轉(zhuan)換成模(mo)(mo)擬信(xin)(xin)號(hao)(hao),然后發送(song)至(zhi)電(dian)(dian)壓功(gong)放(fang)模(mo)(mo)塊(kuai)(kuai)(kuai)和電(dian)(dian)流功(gong)放(fang)模(mo)(mo)塊(kuai)(kuai)(kuai)。電(dian)(dian)壓功(gong)放(fang)模(mo)(mo)塊(kuai)(kuai)(kuai)用于(yu)對D/A模(mo)(mo)塊(kuai)(kuai)(kuai)輸(shu)(shu)出(chu)的電(dian)(dian)壓信(xin)(xin)號(hao)(hao)進行放(fang)大(da),輸(shu)(shu)出(chu)到現(xian)場合并單(dan)(dan)元模(mo)(mo)擬電(dian)(dian)壓輸(shu)(shu)入端口(kou);電(dian)(dian)流功(gong)放(fang)模(mo)(mo)塊(kuai)(kuai)(kuai)將 D/A 模(mo)(mo)塊(kuai)(kuai)(kuai)輸(shu)(shu)出(chu)的電(dian)(dian)流信(xin)(xin)號(hao)(hao)進行放(fang)大(da),輸(shu)(shu)出(chu)到現(xian)場合并單(dan)(dan)元模(mo)(mo)擬電(dian)(dian)流輸(shu)(shu)入端口(kou)。
信號處理模塊同(tong)時與 FT3信號接(jie)口模塊、SV信號接(jie)口模塊、控(kong)制端接(jie)口模塊、時鐘同(tong)步模塊、現(xian)場動作反饋模塊和D/A模塊連接(jie)。信號處理模塊運行邏(luo)輯(ji)如圖(tu)3所(suo)示。
2.2 通信組網技術
保護測(ce)(ce)試(shi)管理主站與(yu)分布式信(xin)號(hao)發生器(qi)的信(xin)息(xi)交換(huan)包(bao)括參數(shu)設置、同步狀(zhuang)態確認、保護動作狀(zhuang)態切換(huan)、測(ce)(ce)試(shi)數(shu)據傳輸(shu)、測(ce)(ce)試(shi)啟停控制(zhi)等。
根(gen)據(ju)智能變(bian)電站中 SV 和 GOOSE 報(bao)文的(de)特點(dian),通(tong)信(xin)組網是測(ce)試主站與分布式信(xin)號(hao)發生器進行參數(shu)(shu)設置和數(shu)(shu)據(ju)傳輸與通(tong)訊的(de)過程。
對于(yu)測試參(can)(can)數中的(de)二(er)進制(zhi)參(can)(can)數如(ru) PT 位置(zhi)、CT極(ji)性(xing)、故障類型(xing)、觸發方式、故障計算(suan)模型(xing)等參(can)(can)數,采用基(ji)于(yu) SV 的(de)通信(xin)協議(yi)和機制(zhi)[13]利用 SV 報文中的(de)保留字段來實(shi)現;對于(yu)通信(xin)過程的(de)同步(bu)狀態確認(ren)、測試啟停控制(zhi)、狀態切換(huan)等過程采用基(ji)于(yu)GOOSE的(de)通信(xin)協議(yi)和機制(zhi)來實(shi)現。
2.3 同步采樣(yang)技(ji)術
基于 P2P 通信(xin)(xin)方式的(de)保護數據(ju)采(cai)(cai)樣(yang)(yang)同步(bu)技(ji)術(shu)[14]實質上是一種從數據(ju)源采(cai)(cai)樣(yang)(yang)到傳輸(shu)保護裝置的(de)采(cai)(cai)樣(yang)(yang)通道延遲計算,根據(ju)需(xu)要通過(guo)插值的(de)方式計算平均時間的(de)樣(yang)(yang)本的(de)方法。P2P通信(xin)(xin)方式在智能站中(zhong)體現為電氣量(liang)由電子式互感器采(cai)(cai)集并發送到保護裝置的(de)過(guo)程(cheng),該(gai)過(guo)程(cheng)的(de)傳輸(shu)延遲見圖4。
電(dian)(dian)氣量傳(chuan)輸(shu)和采樣(yang)(yang)過(guo)程的(de)(de)延(yan)(yan)時(shi)(shi)包括(kuo)電(dian)(dian)子(zi)式(shi)互(hu)感(gan)器信(xin)號傳(chuan)輸(shu)延(yan)(yan)時(shi)(shi) t1、通(tong)道(dao)(dao)(dao)延(yan)(yan)時(shi)(shi) t2、采集過(guo)程延(yan)(yan)時(shi)(shi)t3、通(tong)道(dao)(dao)(dao)延(yan)(yan)時(shi)(shi)t4、MU過(guo)程延(yan)(yan)時(shi)(shi)t5、MU到(dao)保(bao)護(hu)設備的(de)(de)通(tong)道(dao)(dao)(dao)延(yan)(yan)時(shi)(shi) t6、處(chu)理保(bao)護(hu)裝(zhuang)置中(zhong)從接(jie)收采樣(yang)(yang)數據(ju)到(dao)同步(bu)操作的(de)(de)延(yan)(yan)時(shi)(shi) t7,其(qi)中(zhong)用(yong)于數據(ju)采樣(yang)(yang)的(de)(de)電(dian)(dian)子(zi)式(shi)互(hu)感(gan)器延(yan)(yan)時(shi)(shi)為T1=t1+t2+t3。相關規(gui)范規(gui)定,T1≤2Ts(Ts為采樣(yang)(yang)周期(qi),4 kHz采樣(yang)(yang)頻率下為250 μs)。發送(song)到(dao) MU 的(de)(de)采樣(yang)(yang)數據(ju)的(de)(de)通(tong)道(dao)(dao)(dao)延(yan)(yan)遲 t4很小可以(yi)忽略,那么從電(dian)(dian)子(zi)變壓(ya)(ya)器到(dao) MU 的(de)(de)延(yan)(yan)時(shi)(shi)為 T1,因(yin)此,MU 接(jie)收到(dao)的(de)(de) SV 包含處(chu)理采樣(yang)(yang)的(de)(de)一次(ci)電(dian)(dian)壓(ya)(ya)和電(dian)(dian)流(liu)的(de)(de)耗時(shi)(shi)信(xin)息。
MU在接收SV后解析報(bao)文中的(de)(de)(de)延時(shi)信息T1,實際采(cai)樣(yang)(yang)時(shi)間可通(tong)過(guo)從(cong)接收時(shi)間減(jian)去(qu)T1得到,經過(guo)延遲校正后,MU將(jiang)重新采(cai)樣(yang)(yang)SV,然后將(jiang)MU中的(de)(de)(de)多個采(cai)樣(yang)(yang)統一(yi)同步。以單(dan)一(yi)的(de)(de)(de)MU為單(dan)位的(de)(de)(de)處(chu)理(li)延時(shi)很難準(zhun)(zhun)確(que)估計,但對于同類型的(de)(de)(de)成(cheng)熟(shu)產品來(lai)說相對穩定(ding),可以通(tong)過(guo)測試(shi)其準(zhun)(zhun)確(que)性得到以滿足工程(cheng)(cheng)應用(yong)的(de)(de)(de)需要。從(cong)開始(shi)采(cai)樣(yang)(yang)數據到MU發送(song)SV的(de)(de)(de)整個過(guo)程(cheng)(cheng)延時(shi)(以MU為單(dan)位)為T2=T1+t5,MU 在 SV 消息中標記(ji)該時(shi)間戳,然后發送(song)至保護裝置。
對于從MU到保護設(she)備(bei)的(de)信道延時(shi)t6,光纖鏈路中的(de)數據傳(chuan)輸(shu)速率約為(wei) 2×108 m/s,當(dang)保護設(she)備(bei)和(he) MU 之間(jian)(jian)的(de)傳(chuan)輸(shu)距離較短時(shi),延時(shi)部分可(ke)以(yi)忽(hu)略(lve);當(dang)傳(chuan)輸(shu)距離較長時(shi),應估計延時(shi)為(wei) t6,并用于保護中的(de)時(shi)間(jian)(jian)補償計算。SV 通常不能被直(zhi)接用于保護裝置(zhi)(zhi),需要緩存(cun)處(chu)理(li),處(chu)理(li)時(shi)間(jian)(jian)約為(wei) t7。保護裝置(zhi)(zhi)可(ke)以(yi)通過(guo)標記數據存(cun)儲在(zai)緩沖(chong)區中并從中讀取(qu)的(de)相(xiang)對時(shi)間(jian)(jian)來計算t7的(de)值。
完成(cheng)上述步驟(zou)后,可計算電氣量(liang)采樣,在經過(guo)數據處理并傳輸至保護裝置的延時T為T=T2+t7=T1+t5+t7=t1+t2+t3+t5+t7 (1)
如(ru)果中間傳輸(shu)距(ju)離較(jiao)長,則還需要包含 t4和t6,如(ru)式(2):T=t1+t2+t3+t4+t5+t6+t7 (2)
MU傳(chuan)輸的(de)數據(ju)(ju)采樣(yang)(yang)頻率高于傳(chuan)統的(de)保(bao)(bao)護裝置(zhi),不適合傳(chuan)統的(de)保(bao)(bao)護算法。為了解決這些問題,保(bao)(bao)護裝置(zhi)需(xu)要根據(ju)(ju)采樣(yang)(yang)頻率的(de)需(xu)要從(cong)不同的(de)間隔重新(xin)采樣(yang)(yang) SVs(sample value,多個采樣(yang)(yang)值),從(cong)而(er)獲得采樣(yang)(yang)數據(ju)(ju),*終用于保(bao)(bao)護的(de)計算。
從以(yi)上(shang)過程(cheng)可以(yi)看出(chu),由于數(shu)據采樣和(he)傳(chuan)輸是在(zai) P2P 中完成(cheng)的(de),因此可以(yi)估計出(chu)各個(ge)階(jie)段的(de)延時,以(yi)確(que)保保護動(dong)作的(de)多間隔(ge)采樣數(shu)據同步,滿足工程(cheng)應用對保護設(she)備的(de)需求。基(ji)于P2P通信(xin)方(fang)式的(de)保護傳(chuan)輸采樣方(fang)法具有以(yi)下優點:
1)保護算法的(de)執行不依賴外部時(shi)鐘(zhong)源,與時(shi)鐘(zhong)信(xin)號(hao)同步方式(shi)相比,提(ti)高了保護功(gong)能的(de)獨立性和可(ke)靠性。
2)SV 傳(chuan)輸(shu)鏈路簡(jian)單,無需交換網(wang)絡,不受交換性能、故障(zhang)和網(wang)絡異常因素的影響。
以上兩(liang)點對保護裝置(zhi)的可(ke)靠運行至關重(zhong)要,因此,在外部時鐘同(tong)步系統和網(wang)絡(luo)可(ke)靠性(xing)不能(neng)滿足需求(qiu)的情況下,P2P 通信(xin)模式在智能(neng)變電(dian)站發展的初期(qi)得到(dao)了廣(guang)泛應用。
實現控(kong)制(zhi)終(zhong)(zhong)端(duan)(duan)通(tong)過(guo)智能變電站后(hou)備光纖控(kong)制(zhi)多(duo)臺分(fen)布式(shi)(shi)信(xin)(xin)號(hao)(hao)發生(sheng)器(qi)協(xie)同測(ce)試(shi)是分(fen)布式(shi)(shi)測(ce)試(shi)的重點。控(kong)制(zhi)端(duan)(duan)通(tong)過(guo)分(fen)布式(shi)(shi)信(xin)(xin)號(hao)(hao)發生(sheng)器(qi)接口(kou)模(mo)(mo)塊傳輸(shu)測(ce)試(shi)參數(shu)表(biao),開(kai)始(shi)和結束測(ce)試(shi),切(qie)換(huan)分(fen)布式(shi)(shi)信(xin)(xin)號(hao)(hao)發生(sheng)器(qi)輸(shu)出(chu)信(xin)(xin)號(hao)(hao)狀態。分(fen)布式(shi)(shi)信(xin)(xin)號(hao)(hao)發生(sheng)器(qi)通(tong)過(guo)控(kong)制(zhi)終(zhong)(zhong)端(duan)(duan)接口(kou)模(mo)(mo)塊獲取(qu)測(ce)試(shi)開(kai)始(shi)指令和狀態切(qie)換(huan)指令,并將測(ce)試(shi)結束信(xin)(xin)號(hao)(hao)、測(ce)試(shi)過(guo)程數(shu)據和現場動(dong)作反饋信(xin)(xin)息傳送給控(kong)制(zhi)終(zhong)(zhong)端(duan)(duan)。測(ce)試(shi)平(ping)臺的測(ce)試(shi)流程如圖5所示(shi)。
3 自(zi)動測試方(fang)法(fa)用(yong)例
以本地區(qu)某 330 kV 變電(dian)(dian)站為例,進行保(bao)護功能(neng)自動(dong)測(ce)試技術的驗證,變電(dian)(dian)站主接線如圖 6所示。
以(yi)(yi) 110 kV 線路保(bao)護(hu)裝(zhuang)置(zhi)為例,利用(yong)本(ben)地保(bao)護(hu)自動測試系統對 A、B、C 三套現場線路保(bao)護(hu)裝(zhuang)置(zhi)進(jin)行(xing)多機同步(bu)(bu)自動測試。測試過程包括(kuo)以(yi)(yi)下步(bu)(bu)驟(zou):
1)完(wan)成測試系(xi)統硬(ying)件平(ping)臺的(de)搭建,從就地保護(hu)(hu)測試儀引出三(san)組電(dian)(dian)壓和電(dian)(dian)流(liu)到就地接線轉(zhuan)換裝置(zhi),通過航(hang)空插頭(tou)接口連(lian)接三(san)套現(xian)場保護(hu)(hu)裝置(zhi);
2)從三套(tao)現場保護裝置的ICD(IED capabilitydescription,ICD)文件中提取(qu)相應的設備數據模型文件;
3)基于任意設(she)備的(de)數據模(mo)型,通過測(ce)試用例(li)(li)智能生成(cheng)模(mo)塊(kuai)生成(cheng)整個設(she)備的(de)測(ce)試用例(li)(li);
4)通過自動(dong)測(ce)試主程序創建(jian)多設備測(ce)試記錄(lu)。準備就緒開始(shi)系統(tong)組網,組網完成進(jin)行一鍵(jian)自動(dong)測(ce)試,測(ce)試完成后即可(ke)創建(jian)并生成測(ce)試記錄(lu),生成測(ce)試報告(gao)。
4 結 論
針(zhen)對現(xian)場保護(hu)(hu)裝置測(ce)(ce)試(shi)(shi)的特殊性(xing),提(ti)出(chu)一套基(ji)于模塊化設(she)計思想(xiang)的多(duo)設(she)備同(tong)(tong)步測(ce)(ce)試(shi)(shi)保護(hu)(hu)自動測(ce)(ce)試(shi)(shi)系(xi)統。通過時(shi)鐘(zhong)同(tong)(tong)步技術實(shi)現(xian)設(she)備的同(tong)(tong)步觸發,保證數據采(cai)集的同(tong)(tong)步性(xing),解決了多(duo)區間(jian)采(cai)樣延時(shi)的問題,從(cong)而提(ti)高變電(dian)站(zhan)數據的測(ce)(ce)試(shi)(shi)效率,為后期變電(dian)站(zhan)運(yun)維(wei)工作(zuo)提(ti)供(gong)參考(kao)。