經常燒變頻器只有以下幾種可分析的原因
1、變(bian)頻(pin)器(qi)非品牌產品，國內(nei)生(sheng)產廠家很多質量參差 不(bu)齊，買的變(bian)頻(pin)器(qi)為雜牌便宜貨。
2、初(chu)次使用時許多功能參(can)數未按說明書上的(de)代碼設(she)置到(dao)變(bian)頻器(qi)內，至(zhi)使變(bian)頻器(qi)的(de)過(guo)壓、過(guo)流、超頻等保護功能完(wan)全沒起作用。
3、電(dian)機額(e)(e)定輸(shu)入(ru)功(gong)率(lv)(lv)大于(yu)變頻器的(de)(de)額(e)(e)定輸(shu)出功(gong)率(lv)(lv)，嚴(yan)重(zhong)不匹配。 4、電(dian)機的(de)(de)絕緣或線圈的(de)(de)匝間短路。
5、電機的拖(tuo)動負載過大。
6、220V輸入電壓不穩或(huo)者有接觸不良打(da)火現像(xiang)等等。
下面初步了解一下變頻器及簡單故障分析
通(tong)用(yong)變(bian)(bian)(bian)頻(pin)(pin)(pin)(pin)器(qi)(qi)一(yi)般為(wei)(wei)電(dian)(dian)(dian)(dian)壓(ya)型變(bian)(bian)(bian)頻(pin)(pin)(pin)(pin)器(qi)(qi)，采(cai)用(yong)交(jiao)—直(zhi)(zhi)(zhi)(zhi)—交(jiao)工(gong)作(zuo)方式，即是輸(shu)入(ru)為(wei)(wei)交(jiao)流(liu)(liu)電(dian)(dian)(dian)(dian)源，交(jiao)流(liu)(liu)電(dian)(dian)(dian)(dian)壓(ya)三(san)相(xiang)整流(liu)(liu)橋整流(liu)(liu)后(hou)變(bian)(bian)(bian)為(wei)(wei)直(zhi)(zhi)(zhi)(zhi)流(liu)(liu)電(dian)(dian)(dian)(dian)壓(ya)，然后(hou)直(zhi)(zhi)(zhi)(zhi)流(liu)(liu)電(dian)(dian)(dian)(dian)壓(ya)經三(san)相(xiang)橋式逆變(bian)(bian)(bian)電(dian)(dian)(dian)(dian)路變(bian)(bian)(bian)換為(wei)(wei)調壓(ya)調頻(pin)(pin)(pin)(pin)的(de)(de)三(san)相(xiang)交(jiao)流(liu)(liu)電(dian)(dian)(dian)(dian)輸(shu)出到負載。當變(bian)(bian)(bian)頻(pin)(pin)(pin)(pin)器(qi)(qi)剛上電(dian)(dian)(dian)(dian)時，由于直(zhi)(zhi)(zhi)(zhi)流(liu)(liu)側的(de)(de)平(ping)波電(dian)(dian)(dian)(dian)容(rong)容(rong)量非常大(da)(da)，充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)(liu)很大(da)(da)，通(tong)常采(cai)用(yong)一(yi)個起(qi)(qi)(qi)動電(dian)(dian)(dian)(dian)阻來限制充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)(liu)，常見的(de)(de)變(bian)(bian)(bian)頻(pin)(pin)(pin)(pin)起(qi)(qi)(qi)動兩種電(dian)(dian)(dian)(dian)路，變(bian)(bian)(bian)頻(pin)(pin)(pin)(pin)器(qi)(qi)通(tong)電(dian)(dian)(dian)(dian)充電(dian)(dian)(dian)(dian)完(wan)成后(hou)，控制電(dian)(dian)(dian)(dian)路通(tong)過繼電(dian)(dian)(dian)(dian)器(qi)(qi)的(de)(de)觸點或(huo)晶閘(zha)管將電(dian)(dian)(dian)(dian)阻短(duan)路，起(qi)(qi)(qi)動電(dian)(dian)(dian)(dian)路故(gu)障一(yi)般表現(xian)為(wei)(wei)起(qi)(qi)(qi)動電(dian)(dian)(dian)(dian)阻燒壞，變(bian)(bian)(bian)頻(pin)(pin)(pin)(pin)器(qi)(qi)報(bao)警顯示為(wei)(wei)直(zhi)(zhi)(zhi)(zhi)流(liu)(liu)母線電(dian)(dian)(dian)(dian)壓(ya)故(gu)障，一(yi)般設(she)(she)計者(zhe)在設(she)(she)計變(bian)(bian)(bian)頻(pin)(pin)(pin)(pin)器(qi)(qi)的(de)(de)起(qi)(qi)(qi)動電(dian)(dian)(dian)(dian)路時，為(wei)(wei)了(le)減少變(bian)(bian)(bian)頻(pin)(pin)(pin)(pin)器(qi)(qi)的(de)(de)體積選擇起(qi)(qi)(qi)動電(dian)(dian)(dian)(dian)阻，都選擇小一(yi)些，電(dian)(dian)(dian)(dian)阻值(zhi)在10～50Ω，功(gong)率為(wei)(wei)10～50W。
當(dang)變頻(pin)(pin)器(qi)的(de)(de)(de)交流輸(shu)入(ru)電源頻(pin)(pin)繁通時(shi)，或者旁(pang)路接觸(chu)器(qi)的(de)(de)(de)觸(chu)點(dian)接觸(chu)不良時(shi)，以及旁(pang)路晶閘管的(de)(de)(de)導通阻值(zhi)變大時(shi)，都會導致起動電阻燒(shao)壞(huai)。如遇此情況，可購(gou)買同規格(ge)的(de)(de)(de)電阻換(huan)之，同時(shi)必須找(zhao)出(chu)引出(chu)電阻燒(shao)壞(huai)的(de)(de)(de)原因。如果故障是(shi)由(you)輸(shu)入(ru)側(ce)電源頻(pin)(pin)率開合引起的(de)(de)(de)，必須消(xiao)除這(zhe)種現象才能(neng)將變頻(pin)(pin)器(qi)投入(ru)使用(yong)；如果故障是(shi)由(you)旁(pang)路繼電器(qi)觸(chu)點(dian)或旁(pang)路晶閘管引起，則(ze)必須更換(huan)這(zhe)些器(qi)件(jian)。
例(li)如一臺三相(xiang)變(bian)頻器狀態正(zheng)常，但調(diao)不到(dao)高(gao)速(su)運(yun)行，經檢查，變(bian)頻器并(bing)無故(gu)障，參數設置正(zheng)確(que)，調(diao)速(su)輸入(ru)(ru)信號正(zheng)常，上電(dian)(dian)運(yun)行時(shi)(shi)測試出現變(bian)頻器直流(liu)母線電(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)只(zhi)有 450V左右，正(zheng)常值為580～600V，再測輸入(ru)(ru)側，發現缺(que)了(le)一相(xiang)，故(gu)障原(yuan)因是(shi)輸入(ru)(ru)側的(de)(de)一個空(kong)氣(qi)開關(guan)的(de)(de)一相(xiang)接(jie)觸不良造(zao)(zao)成(cheng)的(de)(de)，為什(shen)么變(bian)頻器輸入(ru)(ru)缺(que)相(xiang)不報警仍能在低頻段工作(zuo)(zuo)呢?實際(ji)上變(bian)頻器缺(que)一相(xiang)輸入(ru)(ru)時(shi)(shi)，是(shi)可以工作(zuo)(zuo)的(de)(de)，多數變(bian)頻器的(de)(de)母線電(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)下限(xian)為400V，即是(shi)當(dang)直流(liu)母線電(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)降至400V以下時(shi)(shi)，變(bian)頻器才報告直流(liu)母線低電(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)故(gu)障。當(dang)兩相(xiang)輸入(ru)(ru)時(shi)(shi)，直流(liu)母線電(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)為380*1.2＝452V>400V。當(dang)變(bian)頻器不運(yun)行時(shi)(shi)，由于(yu)平波電(dian)(dian)容的(de)(de)作(zuo)(zuo)用(yong)，直流(liu)電(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)也可達到(dao)正(zheng)常值，新型的(de)(de)變(bian)頻器都是(shi)采用(yong)PWM控制(zhi)技術(shu)，調(diao)壓(ya)(ya)(ya)(ya)(ya)調(diao)頻的(de)(de)工作(zuo)(zuo)在逆變(bian)橋完成(cheng)，所以在低頻段輸入(ru)(ru)缺(que)相(xiang)仍可以正(zheng)常工作(zuo)(zuo)，但因為輸入(ru)(ru)電(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)低輸出電(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)低，造(zao)(zao)成(cheng)異步電(dian)(dian)機轉矩低，頻率上不去。
出(chu)(chu)現這(zhe)種故(gu)障顯(xian)示時(shi)，首先檢(jian)查加(jia)速時(shi)間(jian)參(can)數是(shi)(shi)否(fou)(fou)太短，力(li)矩提升(sheng)參(can)數是(shi)(shi)否(fou)(fou)太大，然后檢(jian)查負載(zai)是(shi)(shi)否(fou)(fou)太重(zhong)。如果(guo)無這(zhe)些現象，可以斷開輸(shu)出(chu)(chu)側(ce)的電流互感器和直(zhi)流側(ce)的霍爾電流檢(jian)測點，復位后運行，看是(shi)(shi)否(fou)(fou)出(chu)(chu)現過(guo)流現象，如果(guo)出(chu)(chu)現的話，很可能是(shi)(shi) 1PM模塊(kuai)(kuai)出(chu)(chu)現故(gu)障，因(yin)為1PM模塊(kuai)(kuai)內含有過(guo)壓(ya)過(guo)流、欠壓(ya)、過(guo)載(zai)、過(guo)熱、缺相、短路等保護功(gong)能，而這(zhe)些故(gu)障信號都是(shi)(shi)經模塊(kuai)(kuai)控制引腳的輸(shu)出(chu)(chu)Fn引腳傳送到微(wei)控器的，微(wei)控器接收到故(gu)障信息(xi)后，一(yi)方面(mian)封鎖脈沖(chong)輸(shu)出(chu)(chu)，另一(yi)方面(mian)將故(gu)障信息(xi)顯(xian)示在(zai)面(mian)板上，一(yi)般更換(huan)1PM模塊(kuai)(kuai)。
變(bian)頻(pin)(pin)(pin)(pin)器(qi)(qi)出現過壓(ya)(ya)故障，一(yi)般是(shi)雷雨(yu)天氣，由(you)于(yu)雷電(dian)(dian)(dian)串入變(bian)頻(pin)(pin)(pin)(pin)器(qi)(qi)的(de)(de)電(dian)(dian)(dian)源(yuan)中，使變(bian)頻(pin)(pin)(pin)(pin)器(qi)(qi)直(zhi)流側的(de)(de)電(dian)(dian)(dian)壓(ya)(ya)檢測器(qi)(qi)動作而(er)跳閘，在(zai)(zai)這種(zhong)情(qing)況下，通(tong)常只(zhi)須斷(duan)開變(bian)頻(pin)(pin)(pin)(pin)器(qi)(qi)電(dian)(dian)(dian)源(yuan) 1min左右，再合上電(dian)(dian)(dian)源(yuan)，即可復位；另一(yi)種(zhong)情(qing)況是(shi)變(bian)頻(pin)(pin)(pin)(pin)器(qi)(qi)驅(qu)動大(da)慣性負(fu)載(zai)，就(jiu)出現過壓(ya)(ya)現象(xiang)，因為(wei)(wei)這種(zhong)情(qing)況下，變(bian)頻(pin)(pin)(pin)(pin)器(qi)(qi)的(de)(de)減(jian)速停(ting)止(zhi)屬于(yu)再生制動，在(zai)(zai)停(ting)止(zhi)過程中，變(bian)頻(pin)(pin)(pin)(pin)器(qi)(qi)的(de)(de)輸出頻(pin)(pin)(pin)(pin)率按線性下降，而(er)負(fu)載(zai)電(dian)(dian)(dian)機(ji)的(de)(de)頻(pin)(pin)(pin)(pin)率高于(yu)變(bian)頻(pin)(pin)(pin)(pin)器(qi)(qi)的(de)(de)輸出頻(pin)(pin)(pin)(pin)率，負(fu)載(zai)電(dian)(dian)(dian)機(ji)處于(yu)發電(dian)(dian)(dian)狀(zhuang)態，機(ji)械(xie)能(neng)轉(zhuan)化為(wei)(wei)電(dian)(dian)(dian)能(neng)，并被變(bian)頻(pin)(pin)(pin)(pin)器(qi)(qi)直(zhi)流側的(de)(de)平波電(dian)(dian)(dian)容吸收，當這種(zhong)能(neng)量(liang)足(zu)夠大(da)時，就(jiu)會(hui)產生所謂的(de)(de)“泵升現象(xiang)”，變(bian)頻(pin)(pin)(pin)(pin)器(qi)(qi)直(zhi)流側的(de)(de)電(dian)(dian)(dian)壓(ya)(ya)會(hui)超過直(zhi)流母線的(de)(de)最(zui)大(da)電(dian)(dian)(dian)壓(ya)(ya)而(er)跳閘，對于(yu)這種(zhong)故障，一(yi)是(shi)將(jiang)減(jian)速時間參數設置長些或增大(da)制動電(dian)(dian)(dian)阻或增加(jia)制動單元；二(er)是(shi)將(jiang)變(bian)頻(pin)(pin)(pin)(pin)器(qi)(qi)的(de)(de)停(ting)止(zhi)方式(shi)設置為(wei)(wei)自由(you)停(ting)車。
電機發熱，變頻器顯示過載
對(dui)(dui)于已經投入運(yun)(yun)行(xing)的變(bian)頻器(qi)(qi)如果(guo)出現(xian)這(zhe)(zhe)種故障，就必(bi)須檢查負載的狀況(kuang)；對(dui)(dui)于新安(an)裝(zhuang)的變(bian)頻器(qi)(qi)如果(guo)出現(xian)這(zhe)(zhe)種故障，很可能是(shi) V/F曲線設(she)置(zhi)不當或電(dian)(dian)機(ji)參(can)數(shu)設(she)置(zhi)有(you)問題，例如一(yi)(yi)臺新裝(zhuang)變(bian)頻器(qi)(qi)，其驅動的是(shi)一(yi)(yi)臺變(bian)頻電(dian)(dian)機(ji)，電(dian)(dian)機(ji)額定(ding)參(can)數(shu)為220V/50Hz，而(er)變(bian)頻器(qi)(qi)出廠時設(she)置(zhi)為380V/50Hz，由于安(an)裝(zhuang)人員沒有(you)正確(que)設(she)定(ding)變(bian)頻器(qi)(qi)的V/F參(can)數(shu)，導(dao)致電(dian)(dian)機(ji)運(yun)(yun)行(xing)一(yi)(yi)段時間(jian)后轉子(zi)出現(xian)磁飽和，致使電(dian)(dian)機(ji)轉速(su)降低，發熱而(er)過載。所以(yi)在新變(bian)頻器(qi)(qi)使用(yong)以(yi)前，必(bi)須設(she)置(zhi)好該參(can)數(shu)，另外使用(yong)變(bian)頻器(qi)(qi)的無(wu)速(su)度傳感器(qi)(qi)矢量控制方(fang)式時，沒有(you)正確(que)的設(she)置(zhi)負載
電(dian)(dian)(dian)機(ji)(ji)的(de)額定電(dian)(dian)(dian)壓、電(dian)(dian)(dian)流(liu)、容量等(deng)參(can)數，也(ye)會(hui)導致(zhi)(zhi)電(dian)(dian)(dian)機(ji)(ji)熱過載，還(huan)有一(yi)種(zhong)情形(xing)(xing)是設置的(de)變(bian)頻(pin)器載波率過高時，也(ye)會(hui)導致(zhi)(zhi)電(dian)(dian)(dian)機(ji)(ji)發(fa)熱過載，最后一(yi)種(zhong)情形(xing)(xing)是電(dian)(dian)(dian)氣設計者(zhe)設計變(bian)頻(pin)器常(chang)常(chang)在(zai)(zai)低(di)頻(pin)段工作(zuo)，而沒有考(kao)慮到在(zai)(zai)低(di)頻(pin)段工作(zuo)的(de)電(dian)(dian)(dian)機(ji)(ji)散(san)熱變(bian)差(cha)的(de)問題，致(zhi)(zhi)使電(dian)(dian)(dian)機(ji)(ji)工作(zuo)一(yi)段時間后發(fa)熱過載，對于這種(zhong)，需加裝散(san)熱裝置。
