新聞動態
試驗變壓器之擊穿試驗的方法分析
試驗(yan)變(bian)壓器之擊穿試驗(yan)的方法(fa)分析
1、測試方法現狀
目(mu)前(qian)國內電(dian)(dian)力行業，尤(you)其(qi)是供電(dian)(dian)系(xi)統和(he)安裝系(xi)統， 目(mu)前(qian)關于絕緣(yuan)油(you)擊穿電(dian)(dian)壓測試(shi)方(fang)(fang)法(fa)的(de)(de)(de)標(biao)準(zhun)比較常用(yong)(yong)(yong)的(de)(de)(de)有GB/T507—1986《電(dian)(dian)氣(qi)用(yong)(yong)(yong)油(you)絕緣(yuan)強度(du)(du)測定(ding)法(fa)》和(he)DL/T429—1991《電(dian)(dian)力系(xi)統油(you)質試(shi)驗方(fang)(fang)法(fa)》，其(qi)中GB/T507—1986主要參照IEC156《絕緣(yuan)油(you)電(dian)(dian)氣(qi)強度(du)(du)測定(ding)方(fang)(fang)法(fa)》制定(ding)，與IEC156差別(bie)很小(xiao)(xiao)。GB/T507—1986和(he)DL/T429—1991這兩種標(biao)準(zhun)的(de)(de)(de)測試(shi)方(fang)(fang)法(fa)(前(qian)者簡稱“方(fang)(fang)法(fa)一”，后者簡稱“方(fang)(fang)法(fa)二”)差別(bie)較大。絕大多數采(cai)用(yong)(yong)(yong)方(fang)(fang)法(fa)二測試(shi)絕緣(yuan)油(you)擊穿電(dian)(dian)壓，即以平板倒(dao)角(jiao)形電(dian)(dian)極和(he)較小(xiao)(xiao)的(de)(de)(de)油(you)杯(bei)進行測試(shi)，但又忽(hu)略了(le)DL/T429—1991中的(de)(de)(de)注(zhu)釋，無論是什(shen)么(me)狀態(tai)的(de)(de)(de)油(you)，從什(shen)么(me)電(dian)(dian)壓等級的(de)(de)(de)電(dian)(dian)氣(qi)設備中采(cai)集的(de)(de)(de)油(you)樣(yang)，統統都用(yong)(yong)(yong)方(fang)(fang)法(fa)二進行測試(shi)。
2、原因分析
在電(dian)力系統(tong)中基本上采用方(fang)法(fa)二(er)測試(shi)絕(jue)緣油擊穿電(dian)壓，這種狀況的形成有(you)(you)歷史沿革的原(yuan)因(yin)，也有(you)(you)方(fang)法(fa)一用油量大的原(yuan)因(yin)。
多(duo)年來，各用(yong)(yong)(yong)(yong)(yong)油(you)(you)(you)(you)(you)(you)部門一(yi)(yi)(yi)直(zhi)采(cai)(cai)(cai)(cai)用(yong)(yong)(yong)(yong)(yong)方法二進行(xing)擊(ji)(ji)穿(chuan)(chuan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)(de)(de)測(ce)(ce)(ce)試(shi)(shi)，相應(ying)的(de)(de)(de)試(shi)(shi)驗(yan)設(she)(she)備(如(ru)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)、油(you)(you)(you)(you)(you)(you)杯)都為(wei)適(shi)應(ying)方法二而設(she)(she)計(ji)。要嚴(yan)格(ge)(ge)執行(xing)標準，針對(dui)(dui)(dui)不(bu)(bu)(bu)(bu)同(tong)油(you)(you)(you)(you)(you)(you)樣，隨(sui)時(shi)更換油(you)(you)(you)(you)(you)(you)杯、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)，必須對(dui)(dui)(dui)測(ce)(ce)(ce)試(shi)(shi)設(she)(she)備進行(xing)更新改造，這給(gei)試(shi)(shi)驗(yan)人員增添(tian)了許多(duo)麻(ma)煩。絕(jue)大多(duo)數情(qing)況下(xia)，試(shi)(shi)驗(yan)人員就用(yong)(yong)(yong)(yong)(yong)一(yi)(yi)(yi)種電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)、一(yi)(yi)(yi)種油(you)(you)(you)(you)(you)(you)杯測(ce)(ce)(ce)試(shi)(shi)所有油(you)(you)(you)(you)(you)(you)樣，若試(shi)(shi)驗(yan)結果(guo)(guo)能滿足不(bu)(bu)(bu)(bu)同(tong)等(deng)級要求的(de)(de)(de)絕(jue)緣(yuan)油(you)(you)(you)(you)(you)(you)擊(ji)(ji)穿(chuan)(chuan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)標準，這也是(shi)(shi)一(yi)(yi)(yi)種不(bu)(bu)(bu)(bu)錯的(de)(de)(de)選(xuan)擇，而且(qie)不(bu)(bu)(bu)(bu)會產生任何(he)分歧，但(dan)是(shi)(shi)，如(ru)果(guo)(guo)測(ce)(ce)(ce)定(ding)值(zhi)介于(yu)(yu)合格(ge)(ge)與不(bu)(bu)(bu)(bu)合格(ge)(ge)之間，麻(ma)煩就出現了。例(li)如(ru)，需測(ce)(ce)(ce)定(ding)一(yi)(yi)(yi)臺500kV運行(xing)中變壓(ya)(ya)(ya)(ya)器(qi)油(you)(you)(you)(you)(you)(you)的(de)(de)(de)擊(ji)(ji)穿(chuan)(chuan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，采(cai)(cai)(cai)(cai)用(yong)(yong)(yong)(yong)(yong)平(ping)(ping)板(ban)倒(dao)(dao)(dao)(dao)角(jiao)(jiao)形(xing)(xing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)和(he)(he)小油(you)(you)(you)(you)(you)(you)杯，以(yi)及相配套的(de)(de)(de)升壓(ya)(ya)(ya)(ya)設(she)(she)備等(deng)試(shi)(shi)驗(yan)設(she)(she)備，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)之間距離2.5mm，測(ce)(ce)(ce)定(ding)的(de)(de)(de)結果(guo)(guo)為(wei)46k V，這顯然不(bu)(bu)(bu)(bu)滿足GB/T7595—2000規(gui)定(ding)的(de)(de)(de)擊(ji)(ji)穿(chuan)(chuan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)不(bu)(bu)(bu)(bu)小于(yu)(yu)50kV的(de)(de)(de)要求。但(dan)是(shi)(shi)此時(shi)并不(bu)(bu)(bu)(bu)能判(pan)斷此油(you)(you)(you)(you)(you)(you)樣不(bu)(bu)(bu)(bu)合格(ge)(ge)，因(yin)為(wei)按照(zhao)DL/T429—1991中的(de)(de)(de)注釋規(gui)定(ding)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)高于(yu)(yu)220kV的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)氣設(she)(she)備的(de)(de)(de)油(you)(you)(you)(you)(you)(you)擊(ji)(ji)穿(chuan)(chuan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)試(shi)(shi)驗(yan)應(ying)按方法一(yi)(yi)(yi)進行(xing)。要判(pan)斷此油(you)(you)(you)(you)(you)(you)樣是(shi)(shi)否合格(ge)(ge)，就必須再取樣，用(yong)(yong)(yong)(yong)(yong)球蓋形(xing)(xing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)和(he)(he)大油(you)(you)(you)(you)(you)(you)杯進行(xing)試(shi)(shi)驗(yan)。這樣無疑給(gei)試(shi)(shi)驗(yan)工作帶(dai)來更大的(de)(de)(de)麻(ma)煩。有些單位則采(cai)(cai)(cai)(cai)取加深本體油(you)(you)(you)(you)(you)(you)處(chu)理的(de)(de)(de)手段，仍用(yong)(yong)(yong)(yong)(yong)平(ping)(ping)板(ban)倒(dao)(dao)(dao)(dao)角(jiao)(jiao)形(xing)(xing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)，直(zhi)至測(ce)(ce)(ce)定(ding)值(zhi)合格(ge)(ge)為(wei)止。這樣做(zuo)使(shi)絕(jue)緣(yuan)油(you)(you)(you)(you)(you)(you)的(de)(de)(de)絕(jue)緣(yuan)性更可(ke)靠，但(dan)卻加大了處(chu)理成本，是(shi)(shi)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)不(bu)(bu)(bu)(bu)經濟的(de)(de)(de)。用(yong)(yong)(yong)(yong)(yong)平(ping)(ping)板(ban)倒(dao)(dao)(dao)(dao)角(jiao)(jiao)形(xing)(xing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)、球形(xing)(xing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)和(he)(he)球蓋形(xing)(xing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)測(ce)(ce)(ce)得的(de)(de)(de)擊(ji)(ji)穿(chuan)(chuan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)值(zhi)有顯著的(de)(de)(de)差異，GB/T7959—2000附錄B中對(dui)(dui)(dui)采(cai)(cai)(cai)(cai)用(yong)(yong)(yong)(yong)(yong)3種電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)測(ce)(ce)(ce)定(ding)的(de)(de)(de)擊(ji)(ji)穿(chuan)(chuan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)值(zhi)進行(xing)了比(bi)較(jiao)：采(cai)(cai)(cai)(cai)用(yong)(yong)(yong)(yong)(yong)球形(xing)(xing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)比(bi)采(cai)(cai)(cai)(cai)用(yong)(yong)(yong)(yong)(yong)平(ping)(ping)板(ban)倒(dao)(dao)(dao)(dao)角(jiao)(jiao)形(xing)(xing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)約(yue)高6kV;采(cai)(cai)(cai)(cai)用(yong)(yong)(yong)(yong)(yong)球蓋形(xing)(xing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)比(bi)采(cai)(cai)(cai)(cai)用(yong)(yong)(yong)(yong)(yong)平(ping)(ping)板(ban)倒(dao)(dao)(dao)(dao)角(jiao)(jiao)形(xing)(xing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)高3～6 k V;當油(you)(you)(you)(you)(you)(you)的(de)(de)(de)擊(ji)(ji)穿(chuan)(chuan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)值(zhi)在30kV以(yi)下(xia)時(shi)，球形(xing)(xing)和(he)(he)平(ping)(ping)板(ban)倒(dao)(dao)(dao)(dao)角(jiao)(jiao)形(xing)(xing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)的(de)(de)(de)測(ce)(ce)(ce)定(ding)值(zhi)基本一(yi)(yi)(yi)致(zhi)。但(dan)這只是(shi)(shi)一(yi)(yi)(yi)種統(tong)計(ji)規(gui)律(lv)，不(bu)(bu)(bu)(bu)能簡單地把采(cai)(cai)(cai)(cai)用(yong)(yong)(yong)(yong)(yong)平(ping)(ping)板(ban)倒(dao)(dao)(dao)(dao)角(jiao)(jiao)形(xing)(xing)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)(ji)(ji)測(ce)(ce)(ce)得的(de)(de)(de)擊(ji)(ji)穿(chuan)(chuan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)值(zhi)都加上3～6kV，對(dui)(dui)(dui)單個(ge)油(you)(you)(you)(you)(you)(you)樣來說差別可(ke)能很大，也可(ke)能很小。
方(fang)法一用油(you)(you)量大(da)，需(xu)從電氣(qi)設(she)備(bei)中多次取樣，對于互(hu)感器、電抗器和少(shao)油(you)(you)開關等(deng)少(shao)油(you)(you)電氣(qi)設(she)備(bei)，多次取樣后，油(you)(you)量不足就必須補油(you)(you)。因此(ci)很多單位都選擇(ze)方(fang)法二，以小(xiao)油(you)(you)杯進行測試。
3、試驗方法的改進建(jian)議
(1)方(fang)法(fa)(fa)標(biao)準應向(xiang)國際標(biao)準靠攏。目前(qian)IEC156的(de)試驗(yan)方(fang)法(fa)(fa)是得到世界(jie)上(shang)大多(duo)數國家承(cheng)認的(de)，其通用(yong)性、先進性不容置疑。在標(biao)準化工作中，優先采用(yong)先進的(de)、國際通用(yong)的(de)標(biao)準制(zhi)訂(ding)本(ben)國的(de)標(biao)準是一條(tiao)很重要的(de)原(yuan)則(ze)，GB/T507—1986基(ji)本(ben)上(shang)是參(can)照IEC156制(zhi)訂(ding)的(de)，要求基(ji)本(ben)相同。
(2)考慮到運行中電氣(qi)設備(bei)的(de)油(you)(you)量稍少及測(ce)試油(you)(you)杯的(de)容量稍小對測(ce)試結果影響不大的(de)情況，可對GB/T507—1986中油(you)(you)杯容量的(de)限制放寬，例如(ru)從300～500mL放寬至200～500mL。
(3)方(fang)(fang)法一比方(fang)(fang)法二更(geng)接近于絕緣油(you)的實(shi)際使用情(qing)況，充油(you)電(dian)氣(qi)設備中發生油(you)隙(xi)擊穿是在場強較高又相對(dui)集中的區域，與球(qiu)形或球(qiu)蓋(gai)形電(dian)極(ji)間隙(xi)更(geng)相似，而(er)不同于平板倒(dao)角形電(dian)極(ji)間隙(xi)
