某電業局變電站在一段時間內發生了電抗器連續燒毀的情況,經過測試發現,引起電抗器燒毀的原因是因為流(liu)過(guo)電(dian)抗器(qi)(qi)的諧(xie)波電(dian)流(liu)超標(biao),再加(jia)上本身流(liu)過(guo)的基(ji)波電(dian)流(liu),二者疊(die)加(jia)后(hou)大大超過(guo)了電(dian)抗器(qi)(qi)額(e)定值,電(dian)抗器(qi)(qi)長期在過(guo)電(dian)流(liu)條件下工作,燒壞也就不足為奇。諧(xie)波電(dian)流(liu)超標(biao)只(zhi)是引起電(dian)抗器(qi)(qi)燒毀(hui)的一種(zhong)情(qing)形,其實情(qing)形下文做簡單的總結(jie):
電(dian)(dian)(dian)抗器長(chang)期工作電(dian)(dian)(dian)流過(guo)大(da)(da)的(de)原(yuan)因有:電(dian)(dian)(dian)抗率(lv)選擇(ze)不當(dang),導(dao)致產(chan)生(sheng)放大(da)(da)諧(xie)(xie)波(bo)。諧(xie)(xie)波(bo)是指頻率(lv)為基波(bo)整數倍(bei)數的(de)交流量,它是由負(fu)載的(de)非線性而(er)產(chan)生(sheng)的(de),對電(dian)(dian)(dian)力系統有很大(da)(da)的(de)危害(hai)。當(dang)高次(ci)諧(xie)(xie)波(bo)作用于電(dian)(dian)(dian)容器組(zu)時,會使電(dian)(dian)(dian)容器組(zu)電(dian)(dian)(dian)抗減小,電(dian)(dian)(dian)流增大(da)(da),從而(er)使得(de)系統產(chan)生(sheng)諧(xie)(xie)波(bo)過(guo)電(dian)(dian)(dian)壓,甚至(zhi)諧(xie)(xie)振。串聯電(dian)(dian)(dian)抗器可以有效的(de)減小諧(xie)(xie)波(bo),限制(zhi)合閘涌流,但若電(dian)(dian)(dian)抗率(lv)選擇(ze)不當(dang),也可能會導(dao)致諧(xie)(xie)波(bo)放大(da)(da)。
首先要降(jiang)低電(dian)抗器的(de)(de)(de)電(dian)流,其次在天氣劇烈變化時(shi)的(de)(de)(de)調度(du)和(he)運(yun)(yun)行(xing)(xing)應(ying)(ying)盡量不(bu)改(gai)變無功(gong)補償的(de)(de)(de)運(yun)(yun)行(xing)(xing)方式(shi),運(yun)(yun)行(xing)(xing)人員在巡視時(shi)應(ying)(ying)檢查電(dian)抗器外絕緣的(de)(de)(de)破裂情況、瓷瓶有無明顯放電(dian)現象以及電(dian)抗器有無異響等。