由于(yu)目前工業(ye)企業(ye)中(zhong)(zhong)采用大型整流(liu)及變(bian)流(liu)裝置的設備越來越多，民用建筑(zhu)中(zhong)(zhong)采用變(bian)頻調速的水泵(beng)、風機(ji)已很普遍(bian)，以(yi)致造(zao)成電(dian)(dian)網中(zhong)(zhong)的高次諧(xie)波(bo)的百分比很高。高次諧(xie)波(bo)的允(yun)(yun)許值(zhi)必須(xu)滿足(zu)現(xian)行國家標準《電(dian)(dian)能(neng)質(zhi)量公用電(dian)(dian)網諧(xie)波(bo)》GB／T 14549中(zhong)(zhong)所(suo)列的允(yun)(yun)許值(zhi)，當分組(zu)投切大容(rong)量電(dian)(dian)容(rong)器(qi)組(zu)時，由于(yu)其容(rong)抗的變(bian)化范圍較大，如果系統的諧(xie)波(bo)感抗與(yu)系統的諧(xie)波(bo)容(rong)抗相匹(pi)配(pei)，就會發(fa)生高次諧(xie)波(bo)諧(xie)振，造(zao)成過電(dian)(dian)壓和過電(dian)(dian)流(liu)，嚴(yan)重危及系統及設備的安全運行，所(suo)以(yi)必須(xu)避免。

工(gong)廠無功(gong)補償(chang)元器件改造(zao)方案

在諧波電(dian)(dian)(dian)壓(ya)作用(yong)下，電(dian)(dian)(dian)容器會產生額外(wai)的(de)(de)(de)功率損(sun)耗(hao)，加快絕(jue)緣介質的(de)(de)(de)老(lao)化。更為(wei)嚴重的(de)(de)(de)是(shi)，大(da)量(liang)諧波電(dian)(dian)(dian)流很可能引(yin)發電(dian)(dian)(dian)容器和系統(tong)其他元件之間(jian)的(de)(de)(de)并聯(lian)諧振或(huo)串聯(lian)諧振，造(zao)成(cheng)電(dian)(dian)(dian)容器超載而(er)損(sun)壞。如果對(dui)智能建筑(zhu)配電(dian)(dian)(dian)回(hui)路的(de)(de)(de)諧波進行治理的(de)(de)(de)話，稍有不當(dang)就(jiu)會使斷(duan)路器遮(zhe)斷(duan)能力(li)降低，而(er)且還會導致斷(duan)路器損(sun)壞。除此之外(wai)，感應電(dian)(dian)(dian)動機的(de)(de)(de)額外(wai)損(sun)耗(hao)、電(dian)(dian)(dian)力(li)電(dian)(dian)(dian)纜和配電(dian)(dian)(dian)線路集(ji)膚效應的(de)(de)(de)出現也都是(shi)諧波惹的(de)(de)(de)禍。

沖(chong)擊耐壓試驗(yan)時，被試品(pin)不得帶有過電(dian)(dian)壓保護元(yuan)件，電(dian)(dian)流(liu)互感(gan)(gan)器(qi)的二次側應短(duan)路(lu)并接(jie)(jie)地，低(di)電(dian)(dian)流(liu)比(bi)的電(dian)(dian)流(liu)互感(gan)(gan)器(qi)允許將(jiang)(jiang)一(yi)次側短(duan)接(jie)(jie)。輔助(zhu)(zhu)回路(lu)和控制回路(lu)應能經受(shou)2500v工頻耐壓試驗(yan)，并按以下要求進行：將(jiang)(jiang)輔助(zhu)(zhu)回路(lu)連接(jie)(jie)在一(yi)起，試驗(yan)電(dian)(dian)壓加在它和接(jie)(jie)地骨架之(zhi)間。