主要用于對大容(rong)(rong)量的(de)容(rong)(rong)性電(dian)力(li)設備的(de)現場(chang)交流耐壓(ya)試驗(yan)，如中低壓(ya)、高壓(ya)、超(chao)高壓(ya)的(de)交聯聚(ju)乙(yi)烯(xi)（XLPE）電(dian)纜，全封閉組合電(dian)器（GIS），發電(dian)機定子，大型變壓(ya)器和電(dian)力(li)電(dian)容(rong)(rong)器等。

大家(jia)知道，如上(shang)所(suo)述的(de)(de)(de)(de)變(bian)頻(pin)串聯諧振(zhen)試(shi)(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)(yan)裝置(zhi)其(qi)(qi)交接或預防性試(shi)(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)(yan)用(yong)工(gong)頻(pin)進行交流耐(nai)壓(ya)(ya)(ya)(ya)試(shi)(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)(yan)是(shi)(shi)，但(dan)由于(yu)試(shi)(shi)(shi)(shi)(shi)品電(dian)容量大，需(xu)要的(de)(de)(de)(de)設(she)備(bei)功(gong)率龐大而無(wu)法進行現場試(shi)(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)(yan)，可替代(dai)的(de)(de)(de)(de)調(diao)感(gan)式串聯諧振(zhen)試(shi)(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)(yan)也由于(yu)設(she)備(bei)大且復雜僅用(yong)于(yu)對發電(dian)機定子的(de)(de)(de)(de)耐(nai)壓(ya)(ya)(ya)(ya)試(shi)(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)(yan)和實(shi)驗(yan)(yan)(yan)(yan)室。70年代(dai)末，國(guo)外(wai)電(dian)力部門發現了(le)直流耐(nai)壓(ya)(ya)(ya)(ya)試(shi)(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)(yan)對橡塑絕(jue)緣(yuan)是(shi)(shi)無(wu)效(xiao)的(de)(de)(de)(de)且具有危害性，所(suo)以，目(mu)前(qian)，國(guo)內(nei)已(yi)不推薦甚(shen)至(zhi)禁用(yong)直流法做(zuo)XLPE電(dian)纜(lan)試(shi)(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)(yan)。因(yin)為XLPE電(dian)纜(lan)致命的(de)(de)(de)(de)一個弱點是(shi)(shi)絕(jue)緣(yuan)內(nei)容易產生水樹枝，在(zai)直流電(dian)壓(ya)(ya)(ya)(ya)作(zuo)用(yong)下會迅速(su)變(bian)為電(dian)樹枝并形(xing)成放(fang)電(dian)，加速(su)了(le)絕(jue)緣(yuan)劣化；而單(dan)純(chun)的(de)(de)(de)(de)水樹枝在(zai)交流工(gong)作(zuo)電(dian)壓(ya)(ya)(ya)(ya)下還(huan)能(neng)(neng)保持相(xiang)(xiang)當的(de)(de)(de)(de)耐(nai)壓(ya)(ya)(ya)(ya)值(zhi)并能(neng)(neng)保持一段時(shi)(shi)(shi)間。國(guo)內(nei)外(wai)的(de)(de)(de)(de)調(diao)查研(yan)究和實(shi)踐都表(biao)明，直流耐(nai)壓(ya)(ya)(ya)(ya)試(shi)(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)(yan)不能(neng)(neng)有效(xiao)發現交流電(dian)壓(ya)(ya)(ya)(ya)作(zuo)用(yong)下的(de)(de)(de)(de)某些缺陷，如電(dian)纜(lan)附件內(nei)的(de)(de)(de)(de)機械(xie)(xie)損傷等(deng)。而采用(yong)超(chao)低(di)頻(pin)（0.1Hz）交流試(shi)(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)(yan)方(fang)(fang)法設(she)備(bei)體積雖減小了(le)，但(dan)也有其(qi)(qi)局限性。首(shou)先，目(mu)前(qian)國(guo)內(nei)產品均采用(yong)半電(dian)子半機械(xie)(xie)（大功(gong)率開關每5秒切換一次）方(fang)(fang)式來產生0.1Hz頻(pin)率，輸出波形(xing)無(wu)法達到(dao)等(deng)效(xiao)性好的(de)(de)(de)(de)正弦方(fang)(fang)波；其(qi)(qi)次，試(shi)(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)(yan)時(shi)(shi)(shi)間通常要求1小時(shi)(shi)(shi)（三(san)相(xiang)(xiang)同(tong)做(zuo)時(shi)(shi)(shi)為1小時(shi)(shi)(shi)，若發現有缺陷時(shi)(shi)(shi)再分相(xiang)(xiang)做(zuo)，每相(xiang)(xiang)1小時(shi)(shi)(shi)），工(gong)作(zuo)效(xiao)率是(shi)(shi)比較(jiao)低(di)的(de)(de)(de)(de)；同(tong)時(shi)(shi)(shi)，超(chao)低(di)頻(pin)（0.1Hz）耐(nai)壓(ya)(ya)(ya)(ya)試(shi)(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)(yan)只適用(yong)于(yu)中(zhong)低(di)壓(ya)(ya)(ya)(ya)、高壓(ya)(ya)(ya)(ya)XLPE電(dian)纜(lan)，無(wu)法滿足超(chao)高壓(ya)(ya)(ya)(ya)電(dian)纜(lan)主絕(jue)緣(yuan)的(de)(de)(de)(de)試(shi)(shi)(shi)(shi)(shi)驗(yan)(yan)(yan)(yan)要求。

電網(wang)會議（CIGRE）21—09工(gong)作組于(yu)1997年發表的(de)《高壓擠(ji)包絕緣竣工(gong)驗(yan)(yan)(yan)收試(shi)驗(yan)(yan)(yan)導(dao)則》中指出：30—300Hz交(jiao)流(liu)(liu)耐壓試(shi)驗(yan)(yan)(yan)與工(gong)頻(pin)耐壓的(de)等效(xiao)性良好，推(tui)(tui)薦(jian)用此方法進(jin)行電纜交(jiao)流(liu)(liu)試(shi)驗(yan)(yan)(yan)并(bing)制(zhi)定了(le)試(shi)驗(yan)(yan)(yan)電壓標(biao)(biao)(biao)(biao)準。基于(yu)一些(xie)高校實(shi)驗(yan)(yan)(yan)室(shi)的(de)理論和模擬試(shi)驗(yan)(yan)(yan)研究以及國外十幾年來采用變頻(pin)試(shi)驗(yan)(yan)(yan)的(de)經(jing)驗(yan)(yan)(yan)，其(qi)等效(xiao)性好，效(xiao)率高，設(she)備輕便，試(shi)品(pin)長度幾乎不受限制(zhi)。IEC60840標(biao)(biao)(biao)(biao)準中推(tui)(tui)薦(jian)45—150kV電壓等級敷設(she)后電纜試(shi)驗(yan)(yan)(yan)標(biao)(biao)(biao)(biao)準中增加(jia)了(le)1.7/5min或1/24h的(de)交(jiao)流(liu)(liu)試(shi)驗(yan)(yan)(yan)標(biao)(biao)(biao)(biao)準；IEC62067/CD草案中對220kV等級則只提(ti)出了(le)交(jiao)流(liu)(liu)試(shi)驗(yan)(yan)(yan)的(de)要求，頻(pin)率為：20—300Hz。