主要用(yong)于對大容量的(de)容性電力設備(bei)的(de)現(xian)場交(jiao)流耐(nai)壓試(shi)驗，如中低壓、高壓、超高壓的(de)交(jiao)聯聚乙烯（XLPE）電纜，全封閉組(zu)合電器（GIS），發電機(ji)定子(zi)，大型變壓器和電力電容器等(deng)。
大(da)家知道(dao)，如(ru)上所述的(de)(de)(de)(de)變(bian)頻(pin)(pin)串(chuan)聯諧振(zhen)試(shi)(shi)驗(yan)(yan)裝置(zhi)其交接或(huo)預防(fang)性(xing)試(shi)(shi)驗(yan)(yan)用(yong)(yong)工頻(pin)(pin)進行(xing)交流(liu)耐(nai)(nai)(nai)壓(ya)(ya)(ya)(ya)(ya)(ya)試(shi)(shi)驗(yan)(yan)是，但(dan)由于(yu)試(shi)(shi)品電(dian)(dian)(dian)(dian)(dian)(dian)容量大(da)，需(xu)要(yao)的(de)(de)(de)(de)設備功率(lv)龐大(da)而(er)無(wu)法進行(xing)現(xian)(xian)場(chang)試(shi)(shi)驗(yan)(yan)，可(ke)替代的(de)(de)(de)(de)調(diao)感式串(chuan)聯諧振(zhen)試(shi)(shi)驗(yan)(yan)也由于(yu)設備大(da)且(qie)(qie)復(fu)雜僅用(yong)(yong)于(yu)對(dui)發電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)定子的(de)(de)(de)(de)耐(nai)(nai)(nai)壓(ya)(ya)(ya)(ya)(ya)(ya)試(shi)(shi)驗(yan)(yan)和(he)實驗(yan)(yan)室(shi)。70年代末，國(guo)(guo)外電(dian)(dian)(dian)(dian)(dian)(dian)力部門發現(xian)(xian)了(le)直(zhi)(zhi)流(liu)耐(nai)(nai)(nai)壓(ya)(ya)(ya)(ya)(ya)(ya)試(shi)(shi)驗(yan)(yan)對(dui)橡塑絕(jue)緣(yuan)是無(wu)效(xiao)的(de)(de)(de)(de)且(qie)(qie)具有(you)危害性(xing)，所以，目(mu)前(qian)(qian)，國(guo)(guo)內(nei)已不(bu)(bu)推(tui)薦甚至(zhi)禁用(yong)(yong)直(zhi)(zhi)流(liu)法做XLPE電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)試(shi)(shi)驗(yan)(yan)。因為(wei)XLPE電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)致命的(de)(de)(de)(de)一個弱點是絕(jue)緣(yuan)內(nei)容易產生水(shui)樹枝，在(zai)直(zhi)(zhi)流(liu)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)作(zuo)用(yong)(yong)下會迅速(su)變(bian)為(wei)電(dian)(dian)(dian)(dian)(dian)(dian)樹枝并形成放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)，加(jia)速(su)了(le)絕(jue)緣(yuan)劣(lie)化(hua)；而(er)單純的(de)(de)(de)(de)水(shui)樹枝在(zai)交流(liu)工作(zuo)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)下還能保(bao)持相當的(de)(de)(de)(de)耐(nai)(nai)(nai)壓(ya)(ya)(ya)(ya)(ya)(ya)值并能保(bao)持一段(duan)時(shi)(shi)(shi)(shi)(shi)(shi)間。國(guo)(guo)內(nei)外的(de)(de)(de)(de)調(diao)查(cha)研究和(he)實踐都表明，直(zhi)(zhi)流(liu)耐(nai)(nai)(nai)壓(ya)(ya)(ya)(ya)(ya)(ya)試(shi)(shi)驗(yan)(yan)不(bu)(bu)能有(you)效(xiao)發現(xian)(xian)交流(liu)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)作(zuo)用(yong)(yong)下的(de)(de)(de)(de)某些缺陷，如(ru)電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)附(fu)件內(nei)的(de)(de)(de)(de)機(ji)械損傷等。而(er)采用(yong)(yong)超(chao)(chao)低(di)(di)頻(pin)(pin)（0.1Hz）交流(liu)試(shi)(shi)驗(yan)(yan)方(fang)法設備體積雖(sui)減小了(le)，但(dan)也有(you)其局限性(xing)。首先，目(mu)前(qian)(qian)國(guo)(guo)內(nei)產品均采用(yong)(yong)半電(dian)(dian)(dian)(dian)(dian)(dian)子半機(ji)械（大(da)功率(lv)開關每(mei)5秒切換一次(ci)）方(fang)式來產生0.1Hz頻(pin)(pin)率(lv)，輸出波形無(wu)法達到等效(xiao)性(xing)好(hao)的(de)(de)(de)(de)正弦方(fang)波；其次(ci)，試(shi)(shi)驗(yan)(yan)時(shi)(shi)(shi)(shi)(shi)(shi)間通(tong)常要(yao)求(qiu)1小時(shi)(shi)(shi)(shi)(shi)(shi)（三(san)相同做時(shi)(shi)(shi)(shi)(shi)(shi)為(wei)1小時(shi)(shi)(shi)(shi)(shi)(shi)，若發現(xian)(xian)有(you)缺陷時(shi)(shi)(shi)(shi)(shi)(shi)再分(fen)相做，每(mei)相1小時(shi)(shi)(shi)(shi)(shi)(shi)），工作(zuo)效(xiao)率(lv)是比較低(di)(di)的(de)(de)(de)(de)；同時(shi)(shi)(shi)(shi)(shi)(shi)，超(chao)(chao)低(di)(di)頻(pin)(pin)（0.1Hz）耐(nai)(nai)(nai)壓(ya)(ya)(ya)(ya)(ya)(ya)試(shi)(shi)驗(yan)(yan)只適用(yong)(yong)于(yu)中低(di)(di)壓(ya)(ya)(ya)(ya)(ya)(ya)、高壓(ya)(ya)(ya)(ya)(ya)(ya)XLPE電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)，無(wu)法滿足超(chao)(chao)高壓(ya)(ya)(ya)(ya)(ya)(ya)電(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)主絕(jue)緣(yuan)的(de)(de)(de)(de)試(shi)(shi)驗(yan)(yan)要(yao)求(qiu)。
電(dian)網(wang)會議（CIGRE）21—09工作(zuo)組于1997年發表(biao)的(de)(de)《高壓擠包絕緣竣工驗(yan)(yan)(yan)(yan)(yan)收(shou)試(shi)(shi)驗(yan)(yan)(yan)(yan)(yan)導則》中(zhong)(zhong)指出：30—300Hz交(jiao)流耐壓試(shi)(shi)驗(yan)(yan)(yan)(yan)(yan)與工頻(pin)耐壓的(de)(de)等(deng)(deng)效(xiao)性(xing)良好，推薦(jian)用此方(fang)法進行電(dian)纜交(jiao)流試(shi)(shi)驗(yan)(yan)(yan)(yan)(yan)并制(zhi)定(ding)了(le)試(shi)(shi)驗(yan)(yan)(yan)(yan)(yan)電(dian)壓標(biao)準。基于一些(xie)高校實驗(yan)(yan)(yan)(yan)(yan)室的(de)(de)理論和模擬試(shi)(shi)驗(yan)(yan)(yan)(yan)(yan)研究以(yi)及國外十幾(ji)年來采用變頻(pin)試(shi)(shi)驗(yan)(yan)(yan)(yan)(yan)的(de)(de)經(jing)驗(yan)(yan)(yan)(yan)(yan)，其等(deng)(deng)效(xiao)性(xing)好，效(xiao)率高，設(she)備輕便，試(shi)(shi)品長度幾(ji)乎不受(shou)限制(zhi)。IEC60840標(biao)準中(zhong)(zhong)推薦(jian)45—150kV電(dian)壓等(deng)(deng)級敷設(she)后電(dian)纜試(shi)(shi)驗(yan)(yan)(yan)(yan)(yan)標(biao)準中(zhong)(zhong)增加了(le)1.7/5min或(huo)1/24h的(de)(de)交(jiao)流試(shi)(shi)驗(yan)(yan)(yan)(yan)(yan)標(biao)準；IEC62067/CD草(cao)案中(zhong)(zhong)對220kV等(deng)(deng)級則只提出了(le)交(jiao)流試(shi)(shi)驗(yan)(yan)(yan)(yan)(yan)的(de)(de)要求，頻(pin)率為：20—300Hz。
