從技術原理上講低壓補償濾波模組裝置是在電網中呈感性或容性的元件，由于目前我國中低壓電網以架空線路為主且基本上帶感性負載，所以系統所采用的低壓補償濾波模組裝置多數呈容性，也就是說它是由電容器和相應的附屬設施組成的。

由(you)于負(fu)荷多(duo)數(shu)集中在(zai)配電(dian)(dian)(dian)網絡，所(suo)以(yi)多(duo)年來用于無功補(bu)(bu)償(chang)的電(dian)(dian)(dian)容(rong)器(qi)組(zu)基本上安裝(zhuang)在(zai)電(dian)(dian)(dian)網的中壓側和低壓側，包括35 kV、10 kV和0.4 kV幾個(ge)電(dian)(dian)(dian)壓等級。從運(yun)行需(xu)要上說，低壓智能混(hun)合無功補(bu)(bu)償(chang)裝(zhuang)置由(you)電(dian)(dian)(dian)容(rong)器(qi)組(zu)、投切元(yuan)件、檢(jian)測及保護元(yuan)件組(zu)成。

早在20世紀(ji)70年代，徐(xu)州(zhou)地區就要(yao)求用戶就地安(an)裝(zhuang)400 V低壓(ya)補(bu)(bu)償(chang)裝(zhuang)置(zhi)，并在變(bian)電(dian)(dian)(dian)(dian)(dian)站(zhan)安(an)裝(zhuang)了(le)10 kV的(de)(de)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)(qi)(qi)補(bu)(bu)償(chang)裝(zhuang)置(zhi)。當時的(de)(de)低壓(ya)低壓(ya)智能(neng)(neng)混(hun)合(he)無功補(bu)(bu)償(chang)裝(zhuang)置(zhi)自動(dong)化程度(du)較(jiao)(jiao)低，多(duo)數(shu)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)(qi)(qi)組(zu)(zu)是通過(guo)空(kong)氣開(kai)關(guan)由人(ren)工進(jin)行投切(qie)的(de)(de)，保(bao)護措施簡(jian)單(dan)粗糙，當電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)(qi)(qi)組(zu)(zu)出現整組(zu)(zu)故障時才能(neng)(neng)由空(kong)氣開(kai)關(guan)的(de)(de)熱偶(ou)元件啟動(dong)空(kong)氣開(kai)關(guan)跳(tiao)閘，切(qie)除故障。低壓(ya)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)(qi)(qi)的(de)(de)質量(liang)也不(bu)夠可靠，密(mi)封措施不(bu)良，經常有(you)電(dian)(dian)(dian)(dian)(dian)解(jie)液泄(xie)漏的(de)(de)現象出現。當時在變(bian)電(dian)(dian)(dian)(dian)(dian)站(zhan)安(an)裝(zhuang)的(de)(de)10 kV電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)(qi)(qi)組(zu)(zu)是由單(dan)臺(tai)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)(qi)(qi)組(zu)(zu)合(he)而成(cheng)(cheng)的(de)(de)，或接成(cheng)(cheng)三角形(xing)或接成(cheng)(cheng)星形(xing)，體積較(jiao)(jiao)大，一般要(yao)建造電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)(qi)(qi)室用來(lai)安(an)裝(zhuang)；電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)(qi)(qi)的(de)(de)制作質量(liang)不(bu)高，絕緣材料由紙和(he)氯(lv)化聯苯(ben)浸劑(ji)組(zu)(zu)成(cheng)(cheng)，紙層(ceng)均勻(yun)度(du)不(bu)好，易形(xing)成(cheng)(cheng)局部擊穿，氯(lv)化聯苯(ben)有(you)毒(du)，對人(ren)體和(he)環境均有(you)影響；裝(zhuang)置(zhi)的(de)(de)投切(qie)靠油斷(duan)路(lu)器(qi)(qi)(qi)(qi)完成(cheng)(cheng)，動(dong)作次數(shu)受限制，不(bu)能(neng)(neng)做(zuo)到頻繁投切(qie)；保(bao)護部分由電(dian)(dian)(dian)(dian)(dian)磁(ci)式繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)和(he)單(dan)臺(tai)熔絲組(zu)(zu)成(cheng)(cheng)，電(dian)(dian)(dian)(dian)(dian)磁(ci)式繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)無法實現過(guo)零(ling)投切(qie)，熔絲的(de)(de)保(bao)護特性不(bu)好。

可見，老式低壓補償濾波模組裝置技術性能不好，主要表現為自動化程度偏低和可靠性不高，不能在電網中長期安全可靠運行，運行壽命往往只有二三年。而補償裝置技術性能好壞是決定其是否能被普遍使用的關鍵。