電(dian)(dian)(dian)(dian)(dian)力(li)(li)系統(tong)繼(ji)電(dian)(dian)(dian)(dian)(dian)保(bao)(bao)護(hu)(hu)是電(dian)(dian)(dian)(dian)(dian)氣工(gong)(gong)程(cheng)(cheng)(cheng)及其自(zi)動化專(zhuan)業的(de)主(zhu)要(yao)專(zhuan)業課(ke)(ke)程(cheng)(cheng)(cheng)之一(yi)。電(dian)(dian)(dian)(dian)(dian)力(li)(li)系統(tong)繼(ji)電(dian)(dian)(dian)(dian)(dian)保(bao)(bao)護(hu)(hu)技術是電(dian)(dian)(dian)(dian)(dian)力(li)(li)系統(tong)安全運行(xing)的(de)保(bao)(bao)障,在現代電(dian)(dian)(dian)(dian)(dian)力(li)(li)系統(tong)中(zhong)占(zhan)據十分重(zhong)要(yao)的(de)地(di)位(wei)。本課(ke)(ke)程(cheng)(cheng)(cheng)主(zhu)要(yao)學(xue)(xue)習電(dian)(dian)(dian)(dian)(dian)力(li)(li)系統(tong)繼(ji)電(dian)(dian)(dian)(dian)(dian)保(bao)(bao)護(hu)(hu)的(de)基本知(zhi)識,課(ke)(ke)程(cheng)(cheng)(cheng)內容包(bao)括輸電(dian)(dian)(dian)(dian)(dian)線(xian)路(lu)、變壓器、發電(dian)(dian)(dian)(dian)(dian)機、母線(xian)等電(dian)(dian)(dian)(dian)(dian)力(li)(li)元件和(he)(he)設備的(de)電(dian)(dian)(dian)(dian)(dian)流保(bao)(bao)護(hu)(hu)、距離保(bao)(bao)護(hu)(hu)、差動保(bao)(bao)護(hu)(hu)的(de)基本原(yuan)(yuan)理(li)和(he)(he)整(zheng)定計(ji)算(suan)原(yuan)(yuan)則(ze),自(zi)動重(zhong)合閘的(de)原(yuan)(yuan)理(li),微機繼(ji)電(dian)(dian)(dian)(dian)(dian)保(bao)(bao)護(hu)(hu)的(de)軟(ruan)件硬件組成和(he)(he)基本原(yuan)(yuan)理(li)等。學(xue)(xue)習好本課(ke)(ke)程(cheng)(cheng)(cheng),能(neng)夠培養學(xue)(xue)生(sheng)分析和(he)(he)解決電(dian)(dian)(dian)(dian)(dian)力(li)(li)工(gong)(gong)程(cheng)(cheng)(cheng)中(zhong)有關問(wen)題的(de)能(neng)力(li)(li),為從事繼(ji)電(dian)(dian)(dian)(dian)(dian)保(bao)(bao)護(hu)(hu)相關領域(yu)工(gong)(gong)作打下理(li)論及實(shi)踐基礎。
各高校對電(dian)(dian)力(li)系統繼(ji)電(dian)(dian)保護(hu)課(ke)(ke)(ke)程(cheng)(cheng)(cheng)的教(jiao)(jiao)學(xue)(xue)手段和方(fang)法作出了(le)研究(jiu)和探(tan)索。孫(sun)抗等[1]提出基于(yu)(yu)成(cheng)果導向的教(jiao)(jiao)學(xue)(xue)模式,根據工程(cheng)(cheng)(cheng)教(jiao)(jiao)育(yu)認證的畢業要(yao)求,建立教(jiao)(jiao)學(xue)(xue)目(mu)標(biao),從課(ke)(ke)(ke)堂理論教(jiao)(jiao)學(xue)(xue)、作業、實(shi)驗(yan)三個方(fang)面基于(yu)(yu)成(cheng)果導向進(jin)行教(jiao)(jiao)學(xue)(xue)設計(ji)。羅繼(ji)東等[2]將(jiang) CDIO 工程(cheng)(cheng)(cheng)教(jiao)(jiao)育(yu)理念(nian)應用(yong)于(yu)(yu)繼(ji)電(dian)(dian)保護(hu)課(ke)(ke)(ke)程(cheng)(cheng)(cheng)教(jiao)(jiao)學(xue)(xue),構建了(le)人(ren)才培(pei)(pei)養(yang)(yang)新(xin)模式。湯亞(ya)芳(fang)等[3]建設了(le)適合(he)于(yu)(yu)學(xue)(xue)生自學(xue)(xue)的電(dian)(dian)力(li)系統繼(ji)電(dian)(dian)保護(hu)系列微(wei)課(ke)(ke)(ke)程(cheng)(cheng)(cheng)視頻,利用(yong)該微(wei)課(ke)(ke)(ke)視頻開展(zhan)以(yi)學(xue)(xue)生為中心(xin)的翻轉(zhuan)課(ke)(ke)(ke)堂教(jiao)(jiao)學(xue)(xue)方(fang)式。羅媚媚等[4]利用(yong)電(dian)(dian)網實(shi)訓平臺(tai)和實(shi)踐教(jiao)(jiao)學(xue)(xue)基地,開展(zhan)基于(yu)(yu)校企聯合(he)培(pei)(pei)養(yang)(yang)的繼(ji)電(dian)(dian)保護(hu)原(yuan)理課(ke)(ke)(ke)程(cheng)(cheng)(cheng)教(jiao)(jiao)學(xue)(xue)改革。宋彬彬等[5]在教(jiao)(jiao)學(xue)(xue)中使(shi)用(yong)微(wei)課(ke)(ke)(ke)和 Matlab/Simulink仿真(zhen),探(tan)索了(le)面向**工程(cheng)(cheng)(cheng)人(ren)才培(pei)(pei)養(yang)(yang)的繼(ji)電(dian)(dian)保護(hu)教(jiao)(jiao)學(xue)(xue)方(fang)法。
廣州大學(xue)(xue)正在向高水平大學(xue)(xue)邁進,越(yue)來越(yue)注重學(xue)(xue)生的(de)培養質量。本文(wen)介紹廣州大學(xue)(xue)電(dian)力系(xi)統繼電(dian)保(bao)護(hu)課程理論與實踐并重的(de)教(jiao)學(xue)(xue)改革措施。
一、電(dian)力系統繼電(dian)保護課程的特點(dian)
電(dian)(dian)力(li)系(xi)(xi)統繼電(dian)(dian)保(bao)護(hu)(hu)(hu)(hu)課程(cheng)(cheng)有(you)(you)兩大特(te)(te)點:1. 理(li)論(lun)性(xing)(xing)強(qiang),是(shi)(shi)一門綜合性(xing)(xing)課程(cheng)(cheng)。涉(she)及電(dian)(dian)力(li)系(xi)(xi)統短路(lu)(lu)(lu)計(ji)算、電(dian)(dian)力(li)系(xi)(xi)統穩定(ding)、電(dian)(dian)路(lu)(lu)(lu)原(yuan)理(li)、電(dian)(dian)機學(xue)和(he)(he)數字信(xin)號(hao)處理(li)等(deng)多門課程(cheng)(cheng)的(de)知識。例(li)如(ru)學(xue)習(xi)零(ling)序(xu)電(dian)(dian)流(liu)保(bao)護(hu)(hu)(hu)(hu)時(shi),要(yao)求學(xue)生(sheng)(sheng)熟悉(xi)電(dian)(dian)力(li)系(xi)(xi)統分析(xi)中學(xue)過的(de)序(xu)分量的(de)概念,并會用序(xu)網絡計(ji)算短路(lu)(lu)(lu)電(dian)(dian)流(liu)。在學(xue)習(xi)距離保(bao)護(hu)(hu)(hu)(hu)的(de)振蕩(dang)閉鎖時(shi),要(yao)求掌(zhang)握振蕩(dang)的(de)概念和(he)(he)振蕩(dang)發生(sheng)(sheng)時(shi)的(de)現象,以及振蕩(dang)和(he)(he)故障的(de)區別。在學(xue)習(xi)發電(dian)(dian)機保(bao)護(hu)(hu)(hu)(hu)時(shi),更是(shi)(shi)要(yao)求學(xue)生(sheng)(sheng)對發電(dian)(dian)機的(de)結構和(he)(he)工(gong)作(zuo)原(yuan)理(li)有(you)(you)深入的(de)理(li)解。2. 實(shi)踐性(xing)(xing)強(qiang)。學(xue)習(xi)各種繼電(dian)(dian)保(bao)護(hu)(hu)(hu)(hu)原(yuan)理(li)的(de)*終目(mu)的(de)是(shi)(shi)為(wei)了工(gong)程(cheng)(cheng)應用,這就要(yao)求學(xue)生(sheng)(sheng)不僅要(yao)掌(zhang)握保(bao)護(hu)(hu)(hu)(hu)原(yuan)理(li),還要(yao)熟悉(xi)實(shi)現各種保(bao)護(hu)(hu)(hu)(hu)的(de)硬件(jian)和(he)(he)軟件(jian)。硬件(jian)包括一次和(he)(he)二次回路(lu)(lu)(lu)中的(de)斷(duan)路(lu)(lu)(lu)器(qi)、各種繼電(dian)(dian)器(qi)、電(dian)(dian)壓電(dian)(dian)流(liu)互(hu)感器(qi)等(deng),軟件(jian)包括 A/D 轉換、數字濾波、特(te)(te)征量算法(fa)、動作(zuo)判據(ju)算法(fa)等(deng)。
因(yin)為具(ju)備以上兩個特點,所以電力(li)系統繼電保護課程的學(xue)習難(nan)度比較(jiao)大。教(jiao)(jiao)師往往在(zai)(zai)有限的課堂教(jiao)(jiao)學(xue)時間中(zhong)把(ba)大部分精力(li)花在(zai)(zai)各種(zhong)繼電保護原理的講解(jie)
上,而學(xue)生(sheng)的基(ji)礎參(can)差不齊(qi),理(li)(li)(li)論教學(xue)效果不好。另(ling)外,學(xue)生(sheng)雖然(ran)掌握了繼(ji)電(dian)保護(hu)原(yuan)理(li)(li)(li),但實驗(yan)時看不懂(dong)二(er)次回路接線圖和工作(zuo)原(yuan)理(li)(li)(li),理(li)(li)(li)論教學(xue)和實踐教學(xue)脫節。開展(zhan)電(dian)力系統繼(ji)電(dian)保護(hu)課程的教學(xue)研究與實踐是(shi)一項迫在(zai)眉睫的工作(zuo)。
二、課程(cheng)教學(xue)研究(jiu)與實踐
(一)線上線下混合教學(xue)
2015 年(nian) 4 月,教育(yu)部出臺了(le)(le)《關于(yu)加強(qiang)高(gao)等學(xue)(xue)校在(zai)線(xian)開(kai)放(fang)課(ke)(ke)(ke)程(cheng)(cheng)(cheng)建(jian)設(she)(she)應(ying)用與管理的(de)(de)(de)意見》,各高(gao)校紛紛響應(ying),以立項的(de)(de)(de)方式建(jian)設(she)(she)了(le)(le)一大批在(zai)線(xian)開(kai)放(fang)課(ke)(ke)(ke)程(cheng)(cheng)(cheng)。在(zai)線(xian)開(kai)放(fang)課(ke)(ke)(ke)程(cheng)(cheng)(cheng)拓(tuo)展了(le)(le)教學(xue)(xue)時空(kong),增強(qiang)了(le)(le)教學(xue)(xue)吸引力,激發了(le)(le)學(xue)(xue)習(xi)(xi)者的(de)(de)(de)、學(xue)(xue)習(xi)(xi)積極性(xing)(xing)和(he)(he)(he)自(zi)主性(xing)(xing),擴大了(le)(le)上(shang)等教育(yu)資源受益(yi)面,促進教學(xue)(xue)內(nei)容、方法、模(mo)式和(he)(he)(he)教學(xue)(xue)管理體制機制的(de)(de)(de)改(gai)革[6-9]。我們組建(jian)了(le)(le)電(dian)力系統繼電(dian)保護在(zai)線(xian)開(kai)放(fang)課(ke)(ke)(ke)程(cheng)(cheng)(cheng)教學(xue)(xue)團隊(dui),并于(yu) 2017 年(nian)獲得(de)學(xue)(xue)校在(zai)線(xian)開(kai)放(fang)課(ke)(ke)(ke)程(cheng)(cheng)(cheng)立項。目前已完成教學(xue)(xue)網站(zhan)的(de)(de)(de)建(jian)設(she)(she),設(she)(she)有“課(ke)(ke)(ke)程(cheng)(cheng)(cheng)信(xin)息(xi)”“課(ke)(ke)(ke)程(cheng)(cheng)(cheng)內(nei)容”和(he)(he)(he)“討(tao)論(lun)交流(liu)”三大模(mo)塊。“課(ke)(ke)(ke)程(cheng)(cheng)(cheng)信(xin)息(xi)”模(mo)塊介紹課(ke)(ke)(ke)程(cheng)(cheng)(cheng)的(de)(de)(de)基本情況(kuang),包(bao)括教師(shi)團隊(dui)、課(ke)(ke)(ke)程(cheng)(cheng)(cheng)大綱、考核標準和(he)(he)(he)課(ke)(ke)(ke)程(cheng)(cheng)(cheng)公告等。“課(ke)(ke)(ke)程(cheng)(cheng)(cheng)內(nei)容”是核心模(mo)塊,按(an)照課(ke)(ke)(ke)程(cheng)(cheng)(cheng)章(zhang)節和(he)(he)(he)知識點劃分,每小節(知識點)包(bao)含教學(xue)(xue)視(shi)頻、教學(xue)(xue)課(ke)(ke)(ke)件、客觀(guan)練習(xi)(xi)題(ti)、主觀(guan)練習(xi)(xi)題(ti)、例題(ti)講解等;此外還有測(ce)驗與作業和(he)(he)(he)線(xian)下考試(shi)等功能。“討(tao)論(lun)交流(liu)”模(mo)塊中(zhong)按(an)章(zhang)劃分出若干個(ge)討(tao)論(lun)版,學(xue)(xue)生針對學(xue)(xue)習(xi)(xi)中(zhong)的(de)(de)(de)疑問發帖提(ti)問,教師(shi)和(he)(he)(he)其(qi)他學(xue)(xue)生均(jun)可以回帖,針對問題(ti)展開(kai)討(tao)論(lun),為師(shi)生提(ti)供了(le)(le)協同互動的(de)(de)(de)交流(liu)平臺。
課(ke)(ke)(ke)程上(shang)(shang)線運行后,我們設計了線上(shang)(shang)線下混(hun)合(he)教(jiao)(jiao)(jiao)(jiao)學的(de)(de)模(mo)式(shi),包括課(ke)(ke)(ke)前(qian)(qian)、課(ke)(ke)(ke)堂(tang)和(he)課(ke)(ke)(ke)后 3 個教(jiao)(jiao)(jiao)(jiao)學環(huan)節(jie)。1. 課(ke)(ke)(ke)前(qian)(qian)環(huan)節(jie)。要(yao)求學生(sheng)在線上(shang)(shang)通過觀看教(jiao)(jiao)(jiao)(jiao)學視頻和(he)做測(ce)驗掌握(wo)(wo)知(zhi)識(shi)點(dian),相當于(yu)(yu)把(ba)一部(bu)分(fen)傳統課(ke)(ke)(ke)堂(tang)的(de)(de)教(jiao)(jiao)(jiao)(jiao)學活動前(qian)(qian)移。2. 課(ke)(ke)(ke)堂(tang)環(huan)節(jie)。由(you)于(yu)(yu)學生(sheng)已經(jing)在進入課(ke)(ke)(ke)堂(tang)前(qian)(qian)掌握(wo)(wo)了教(jiao)(jiao)(jiao)(jiao)學知(zhi)識(shi)點(dian),課(ke)(ke)(ke)堂(tang)中僅對重點(dian)和(he)難點(dian)做再次講解(jie)。剩余(yu)的(de)(de)課(ke)(ke)(ke)堂(tang)時間(jian)用(yong)于(yu)(yu)完成課(ke)(ke)(ke)堂(tang)小(xiao)組討論(lun)、小(xiao)測(ce)驗、繼電保(bao)護工程案例分(fen)析和(he)虛擬仿(fang)真演示(shi)等教(jiao)(jiao)(jiao)(jiao)學活動,達到鞏固基礎知(zhi)識(shi)并靈活應用(yong)的(de)(de)目的(de)(de)。3. 課(ke)(ke)(ke)后環(huan)節(jie)。為了檢驗學習(xi)效果,學生(sheng)課(ke)(ke)(ke)后在線上(shang)(shang)完成小(xiao)測(ce)驗。教(jiao)(jiao)(jiao)(jiao)師(shi)根據學生(sheng)測(ce)驗結果和(he)課(ke)(ke)(ke)堂(tang)討論(lun)的(de)(de)表現給出(chu)該次課(ke)(ke)(ke)的(de)(de)成績。混(hun)合(he)式(shi)教(jiao)(jiao)(jiao)(jiao)學模(mo)式(shi)如圖(tu)1 所示(shi)。
(二)啟發(fa)式教學
線(xian)上(shang)教(jiao)學(xue)中,在(zai)每節課(ke)結束(shu)時將(jiang)本次(ci)課(ke)的(de)(de)內容(rong)加以總(zong)結,并針對下(xia)次(ci)課(ke)程(cheng)內容(rong)與(yu)本次(ci)上(shang)課(ke)內容(rong)的(de)(de)不(bu)同(tong)進(jin)行提(ti)問,指(zhi)出(chu)本次(ci)上(shang)課(ke)所提(ti)出(chu)的(de)(de)繼(ji)電保(bao)(bao)護(hu)(hu)方(fang)法的(de)(de)不(bu)足,以及針對該(gai)不(bu)足如(ru)何進(jin)行改進(jin)。這(zhe)樣讓(rang)學(xue)生心存疑(yi)問,促(cu)使其繼(ji)續下(xia)一部(bu)分(fen)的(de)(de)學(xue)習。例(li)如(ru)學(xue)習電流(liu)保(bao)(bao)護(hu)(hu)這(zhe)一部(bu)分(fen)時,首(shou)先講解單電源輻射網絡的(de)(de)Ⅰ段保(bao)(bao)護(hu)(hu)(電流(liu)速(su)斷(duan)(duan)保(bao)(bao)護(hu)(hu)),然后提(ti)出(chu)在(zai)本線(xian)路(lu)末段發(fa)生故障該(gai)怎(zen)么(me)辦?從而引出(chu)Ⅱ段保(bao)(bao)護(hu)(hu)(限時電流(liu)速(su)斷(duan)(duan)保(bao)(bao)護(hu)(hu))。而如(ru)果故障發(fa)生在(zai)相鄰線(xian)路(lu)首(shou)端以外,且相鄰線(xian)路(lu)斷(duan)(duan)路(lu)器又拒絕跳閘,那么(me)僅通(tong)過(guo)前面的(de)(de)保(bao)(bao)護(hu)(hu)方(fang)法無法進(jin)行有(you)效保(bao)(bao)護(hu)(hu)又怎(zen)么(me)辦?這(zhe)樣引入了(le)Ⅲ保(bao)(bao)護(hu)(hu)(定時限過(guo)流(liu)保(bao)(bao)護(hu)(hu))。然后再提(ti)出(chu)如(ru)果是雙側(ce)電源網絡該(gai)如(ru)何?這(zhe)樣又引入了(le)方(fang)向(xiang)性保(bao)(bao)護(hu)(hu)的(de)(de)知識(shi)點。通(tong)過(guo)這(zhe)樣的(de)(de)啟發(fa)讓(rang)學(xue)生對電流(liu)保(bao)(bao)護(hu)(hu)進(jin)行逐步深入的(de)(de)學(xue)習,從而掌(zhang)握電流(liu)保(bao)(bao)護(hu)(hu)相關知識(shi)。
(三)開放式實驗項(xiang)目(mu)
實(shi)驗(yan)(yan)是電(dian)(dian)力系統(tong)繼(ji)電(dian)(dian)保護(hu)(hu)課程(cheng)的(de)重要環節。目前(qian)許多(duo)高校采用廠(chang)家生產的(de)成套設(she)備(bei)開(kai)(kai)展微(wei)機繼(ji)電(dian)(dian)保護(hu)(hu)實(shi)驗(yan)(yan)教(jiao)學(xue)(xue),設(she)備(bei)存在封閉性(xing),對繼(ji)電(dian)(dian)保護(hu)(hu)原(yuan)理(li)的(de)模擬過于(yu)“實(shi)驗(yan)(yan)室(shi)化(hua)”。實(shi)驗(yan)(yan)時(shi)學(xue)(xue)生完成簡單接線(xian)后(hou)觀察(cha)實(shi)驗(yan)(yan)現象,對保護(hu)(hu)原(yuan)理(li)的(de)理(li)解不透徹(che),降(jiang)低了學(xue)(xue)生的(de)實(shi)驗(yan)(yan)興趣,教(jiao)師對學(xue)(xue)生實(shi)驗(yan)(yan)成績的(de)評定也難以做到客(ke)觀。為此,我們對實(shi)驗(yan)(yan)室(shi)現有(you)的(de)微(wei)機保護(hu)(hu)裝置(zhi)進行了改(gai)造,開(kai)(kai)發了三段式電(dian)(dian)流(liu)保護(hu)(hu)開(kai)(kai)放式實(shi)驗(yan)(yan),并獲(huo)得學(xue)(xue)校的(de)示范性(xing)實(shi)驗(yan)(yan)項目立項。
整個(ge)(ge)實(shi)(shi)驗(yan)(yan)(yan)系統由教(jiao)師(shi)工作(zuo)(zuo)站、繼電(dian)(dian)(dian)保(bao)護(hu)(hu)(hu)測試儀(yi)、微(wei)機(ji)(ji)繼電(dian)(dian)(dian)保(bao)護(hu)(hu)(hu)裝置(zhi)(自(zi)主設計,用嵌入式(shi)單(dan)片(pian)機(ji)(ji)開發)、模擬斷(duan)路(lu)器、通信(xin)模塊、學(xue)生計算(suan)(suan)機(ji)(ji)和單(dan)片(pian)機(ji)(ji)下(xia)載器組成。整個(ge)(ge)實(shi)(shi)驗(yan)(yan)(yan)分為三個(ge)(ge)步驟:1. 實(shi)(shi)驗(yan)(yan)(yan)準(zhun)備階段(duan)。實(shi)(shi)驗(yan)(yan)(yan)課前須完(wan)(wan)成預習(xi)報告。上(shang)課后,學(xue)生實(shi)(shi)驗(yan)(yan)(yan)小組在理(li)(li)解(jie)微(wei)機(ji)(ji)保(bao)護(hu)(hu)(hu)實(shi)(shi)驗(yan)(yan)(yan)原(yuan)理(li)(li)的基礎上(shang),根據(ju)教(jiao)師(shi)描述的實(shi)(shi)驗(yan)(yan)(yan)模擬線路(lu)的故障特征和參數,在微(wei)機(ji)(ji)繼電(dian)(dian)(dian)保(bao)護(hu)(hu)(hu)裝置(zhi)上(shang)編寫數據(ju)采集和三段(duan)式(shi)電(dian)(dian)(dian)流保(bao)護(hu)(hu)(hu)算(suan)(suan)法的程序。2. 正式(shi)實(shi)(shi)驗(yan)(yan)(yan)階段(duan)。學(xue)生實(shi)(shi)驗(yan)(yan)(yan)小組對微(wei)機(ji)(ji)繼電(dian)(dian)(dian)保(bao)護(hu)(hu)(hu)裝置(zhi)進行(xing)(xing)自(zi)檢操作(zuo)(zuo),包括硬(ying)件(jian)連接和軟件(jian)測試,確(que)(que)保(bao)裝置(zhi)可(ke)以完(wan)(wan)成實(shi)(shi)驗(yan)(yan)(yan)功(gong)能。若自(zi)檢存在問題,則檢查排除;若自(zi)檢無誤,繼保(bao)裝置(zhi)單(dan)元(yuan)就通過(guo)以太網向教(jiao)師(shi)工作(zuo)(zuo)站發送“READY”就緒信(xin)號(hao),表示裝置(zhi)已經成功(gong)完(wan)(wan)成自(zi)檢,可(ke)以進行(xing)(xing)下(xia)一(yi)步實(shi)(shi)驗(yan)(yan)(yan)。教(jiao)師(shi)確(que)(que)認收到“READY”信(xin)號(hao)后,通過(guo)教(jiao)師(shi)工作(zuo)(zuo)站操縱繼電(dian)(dian)(dian)保(bao)護(hu)(hu)(hu)
測(ce)試儀發出故(gu)障電(dian)壓電(dian)流信號,該故(gu)障信號持續一(yi)定(ding)時間 T(1 根(gen)據(ju)(ju)故(gu)障類(lei)型(xing)和(he)繼電(dian)保護測(ce)試儀輸出特(te)性綜(zong)合設(she)置)。然(ran)后(hou),微機繼電(dian)保護裝置實(shi)(shi)時測(ce)量故(gu)障信號,識(shi)別故(gu)障后(hou),發送相(xiang)應動(dong)作控(kong)制指令至(zhi)模擬斷路器,并且將實(shi)(shi)驗(yan)(yan)(yan)測(ce)量結果和(he)動(dong)作結果通過以(yi)太網(wang)上報(bao)給教(jiao)師工(gong)(gong)作站。教(jiao)師工(gong)(gong)作站接收(shou)到實(shi)(shi)驗(yan)(yan)(yan)數據(ju)(ju)后(hou),進行數據(ju)(ju)展示,并展開實(shi)(shi)驗(yan)(yan)(yan)評(ping)價。實(shi)(shi)驗(yan)(yan)(yan)小組得(de)到實(shi)(shi)驗(yan)(yan)(yan)成(cheng)績 P1,這(zhe)是(shi)由保護動(dong)作的(de)正確(que)性、保護動(dong)作的(de)快速性和(he)故(gu)障測(ce)量的(de)準確(que)性三個(ge)方面確(que)定(ding)的(de)。3. 實(shi)(shi)驗(yan)(yan)(yan)分析(xi)與總結階(jie)段(duan)。學生實(shi)(shi)驗(yan)(yan)(yan)小組根(gen)據(ju)(ju)實(shi)(shi)驗(yan)(yan)(yan)過程完成(cheng)實(shi)(shi)驗(yan)(yan)(yan)報(bao)告。教(jiao)師根(gen)據(ju)(ju)預習報(bao)告、實(shi)(shi)驗(yan)(yan)(yan)操作情況和(he)實(shi)(shi)驗(yan)(yan)(yan)報(bao)告確(que)定(ding)成(cheng)績 P2。根(gen)據(ju)(ju)實(shi)(shi)驗(yan)(yan)(yan)成(cheng)績 P1 和(he)P2 得(de)到總成(cheng)績 P。
該實(shi)驗系(xi)統(tong)有(you)以下優(you)點(dian):1. 將(jiang)電力系(xi)統(tong)現場常用的微(wei)機繼(ji)電保(bao)護裝(zhuang)置和模擬斷路(lu)器應用于(yu)實(shi)驗教學(xue),實(shi)驗操作更(geng)接(jie)近工程實(shi)際(ji);2. 實(shi)驗具(ju)有(you)開放(fang)(fang)性(xing),自主(zhu)設(she)計(ji)的微(wei)機繼(ji)電保(bao)護裝(zhuang)置將(jiang)硬件和軟件向學(xue)生(sheng)開放(fang)(fang),能夠(gou)加深(shen)學(xue)生(sheng)對保(bao)護原理的理解,將(jiang)課(ke)堂所學(xue)的抽象知識轉(zhuan)化為具(ju)體(ti)實(shi)踐,激發學(xue)生(sheng)的主(zhu)動性(xing)和創造(zao)性(xing);3. 一臺繼(ji)電保(bao)護測試儀(yi)可以向多臺微(wei)機繼(ji)電保(bao)護裝(zhuang)置發送電壓電流故障(zhang)信(xin)號(hao),節省傳(chuan)統(tong)多臺成套(tao)實(shi)驗設(she)備的投資(zi)。
開(kai)放(fang)性實驗項目顛覆了繼電(dian)保護實驗教學的思路,大大提升(sheng)了學生(sheng)的興趣,學生(sheng)實驗熱(re)情高漲,教學效果十分突(tu)出。在三段式電(dian)流(liu)保護開(kai)放(fang)式實驗項目開(kai)
發的(de)基(ji)礎上(shang),我們總結出(chu)開放式實驗的(de)教學模式。
(四)虛(xu)擬仿(fang)真(zhen)實驗(yan)
雖然上述開放(fang)性實(shi)驗(yan)在(zai)一(yi)(yi)(yi)定程(cheng)度(du)上彌補了傳(chuan)統(tong)(tong)電(dian)力系(xi)統(tong)(tong)繼電(dian)保(bao)護(hu)實(shi)驗(yan)教(jiao)學的不足(zu),但是開發(fa)一(yi)(yi)(yi)個實(shi)驗(yan)項目需要較高的成(cheng)本,難以覆蓋全(quan)部實(shi)驗(yan)項目。虛(xu)擬(ni)(ni)仿(fang)真實(shi)驗(yan)彌補了這(zhe)方(fang)面的不足(zu)[10]。廣州大學與上海靜一(yi)(yi)(yi)信息科(ke)技有限(xian)公司合(he)作(zuo),將虛(xu)擬(ni)(ni)仿(fang)真實(shi)驗(yan)資源(yuan)引(yin)入實(shi)驗(yan)教(jiao)學,能夠(gou)更為(wei)(wei)緊密地(di)將理(li)論知識銜接(jie)起來。虛(xu)擬(ni)(ni)仿(fang)真平(ping)臺包括一(yi)(yi)(yi)個足(zu)以支撐繼電(dian)保(bao)護(hu)實(shi)驗(yan)所需要的各種一(yi)(yi)(yi)次(ci)(ci)(ci)元器(qi)件(jian)和二(er)次(ci)(ci)(ci)元器(qi)件(jian),能夠(gou)在(zai)平(ping)臺上非常自(zi)(zi)由地(di)使用這(zhe)些元器(qi)件(jian)搭(da)建(jian)各種繼電(dian)保(bao)護(hu)的一(yi)(yi)(yi)次(ci)(ci)(ci)回路和二(er)次(ci)(ci)(ci)回路,完成(cheng)各種電(dian)力系(xi)統(tong)(tong)的繼電(dian)保(bao)護(hu)實(shi)驗(yan)。以“三相一(yi)(yi)(yi)次(ci)(ci)(ci)自(zi)(zi)動重合(he)閘”為(wei)(wei)例,虛(xu)擬(ni)(ni)仿(fang)真環境如(ru)圖(tu) 3 所示。
除(chu)了基本的繼電(dian)(dian)(dian)器原理實(shi)(shi)(shi)驗、三(san)段式電(dian)(dian)(dian)流保(bao)(bao)護(hu)實(shi)(shi)(shi)驗、距離保(bao)(bao)護(hu)實(shi)(shi)(shi)驗、縱聯(lian)保(bao)(bao)護(hu)實(shi)(shi)(shi)驗、自(zi)動重合閘(zha)實(shi)(shi)(shi)驗之外,還開發(fa)了物理平臺無法完成(cheng)(cheng)(cheng)的較復雜電(dian)(dian)(dian)力系(xi)統(tong)繼電(dian)(dian)(dian)保(bao)(bao)護(hu)實(shi)(shi)(shi)驗:110 kV 多母線輻射(she)型電(dian)(dian)(dian)力系(xi)統(tong)虛(xu)擬仿真實(shi)(shi)(shi)驗。該實(shi)(shi)(shi)驗結合工(gong)程(cheng)教育(yu)理念,以成(cheng)(cheng)(cheng)果為(wei)導向,開展(zhan)案例式教學(xue)。該虛(xu)擬仿真實(shi)(shi)(shi)驗可(ke)作(zuo)為(wei)課內綜合性(xing)實(shi)(shi)(shi)驗,也可(ke)作(zuo)為(wei)課程(cheng)的大作(zuo)業(ye)。教師將(jiang)學(xue)生(sheng)分成(cheng)(cheng)(cheng)小組,組員分工(gong)明確(que),自(zi)行查閱(yue)文獻、計算(suan)各整定(ding)值、設計實(shi)(shi)(shi)驗方案、完成(cheng)(cheng)(cheng)實(shi)(shi)(shi)驗操作(zuo)、撰寫報(bao)告。*后教師點(dian)評實(shi)(shi)(shi)驗并指導學(xue)生(sheng)開展(zhan)小組討(tao)論。
虛擬(ni)(ni)仿(fang)真實驗是傳統教學(xue)手段的重(zhong)要延伸與拓展(zhan),學(xue)生可以(yi)隨時隨地進(jin)行(xing)在線實驗,克服(fu)了固定時間地點開展(zhan)實驗的困難(nan)。虛擬(ni)(ni)仿(fang)真實驗具有線上線下融合式學(xue)習的內涵(han),大幅度提(ti)升學(xue)生對繼電保護原理的理解和(he)掌握(wo)程度,提(ti)高(gao)了學(xue)生學(xue)習的興趣。
三、結(jie)束語(yu)
電力系統繼(ji)電保護課(ke)程的特點使教(jiao)(jiao)育改革勢在(zai)必行,廣州大(da)學在(zai)線上線下混合教(jiao)(jiao)學、啟發式教(jiao)(jiao)學、開放式實(shi)驗(yan)和(he)虛擬仿真實(shi)驗(yan)等(deng)方面開展了(le)教(jiao)(jiao)學研究(jiu)與(yu)實(shi)踐。結果表明,這些教(jiao)(jiao)學方法(fa)和(he)手段使學生(sheng)在(zai)教(jiao)(jiao)學過(guo)程中占據主(zhu)導地位,成為學習的主(zhu)人,學習興趣得到很大(da)的提高。學習過(guo)程中理論和(he)實(shi)踐并重,學生(sheng)解決繼(ji)電保護工程實(shi)踐問題(ti)的能力大(da)大(da)增強。改革措施(shi)符合新工科建設和(he)工程教(jiao)(jiao)育認(ren)證理念。