变频(pin)器由主回(hui)(hui)路(lu)、电源回(hui)(hui)路(lu)、IGBT驱动(dong)及保护回(hui)(hui)路(lu)、冷却风扇(shan)等(deng)几部分组成。其结构(gou)多为(wei)(wei)单(dan)元(yuan)化(hua)(hua)或模(mo)块化(hua)(hua)形(xing)式。由于使用方法(fa)不(bu)正确(que)或设置(zhi)环境不(bu)合理，将容易(yi)造成变频(pin)器误(wu)动(dong)作及发生故(gu)障，或者无法(fa)满(man)足预期(qi)的运行效果。为(wei)(wei)防(fang)患于未然，事先(xian)对故(gu)障原因进行认(ren)真分析尤为(wei)(wei)重要。

1、主回路常见故障分析

主(zhu)回(hui)路主(zhu)要(yao)由三相(xiang)或单相(xiang)整流(liu)桥(qiao)、平滑电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容器(qi)(qi)、滤波电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容器(qi)(qi)、IGBT逆变桥(qiao)、限(xian)流(liu)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)、接触(chu)器(qi)(qi)等元件(jian)组成。其(qi)中许多常见故障是由电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)解(jie)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容引(yin)起(qi)。电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)解(jie)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容的(de)(de)寿(shou)(shou)(shou)命主(zhu)要(yao)由加(jia)在(zai)其(qi)两(liang)端(duan)的(de)(de)直流(liu)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)压(ya)和内(nei)部(bu)温(wen)度(du)所决定，在(zai)回(hui)路设(she)计(ji)时(shi)已(yi)经选(xuan)定了电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容器(qi)(qi)的(de)(de)型号，所以内(nei)部(bu)的(de)(de)温(wen)度(du)对(dui)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)解(jie)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容器(qi)(qi)的(de)(de)寿(shou)(shou)(shou)命起(qi)决定作(zuo)用。因此一方面在(zai)安装时(shi)要(yao)考虑适(shi)当的(de)(de)环境温(wen)度(du)，另一方面可以采取措施减(jian)少脉动电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)。采用改善功率因数(shu)的(de)(de)交流(liu)或直流(liu)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)抗器(qi)(qi)可以减(jian)少脉动电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)，从而延长电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)解(jie)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容器(qi)(qi)的(de)(de)寿(shou)(shou)(shou)命。

在电(dian)容(rong)器(qi)(qi)维(wei)护时，通常以比较容(rong)易测量的静电(dian)容(rong)量来判(pan)断电(dian)解电(dian)容(rong)器(qi)(qi)的劣(lie)化情(qing)况，当静电(dian)容(rong)量低于额定值(zhi)的80%，绝缘阻抗在5MΩ以下时，应(ying)考虑更(geng)换电(dian)解电(dian)容(rong)器(qi)(qi)。

2、主回路典型故障分析

故(gu)障(zhang)现象(xiang)：变频器在加速、减速或正常运行时出(chu)现过电(dian)流(liu)跳闸(zha)。

      首先(xian)应区分是(shi)(shi)(shi)(shi)(shi)由(you)于(yu)负(fu)(fu)载原因(yin)，还是(shi)(shi)(shi)(shi)(shi)变频(pin)(pin)(pin)器(qi)(qi)的(de)(de)(de)(de)原因(yin)引(yin)起的(de)(de)(de)(de)。如果是(shi)(shi)(shi)(shi)(shi)变频(pin)(pin)(pin)器(qi)(qi)的(de)(de)(de)(de)故(gu)障(zhang)(zhang)(zhang)，可(ke)通(tong)过(guo)(guo)(guo)历史记录查询在跳闸(zha)时的(de)(de)(de)(de)电(dian)(dian)(dian)(dian)流(liu)，超(chao)过(guo)(guo)(guo)了变频(pin)(pin)(pin)器(qi)(qi)的(de)(de)(de)(de)额(e)定(ding)电(dian)(dian)(dian)(dian)流(liu)或(huo)电(dian)(dian)(dian)(dian)子(zi)(zi)热(re)继电(dian)(dian)(dian)(dian)器(qi)(qi)的(de)(de)(de)(de)设(she)定(ding)值，而三相(xiang)电(dian)(dian)(dian)(dian)压和电(dian)(dian)(dian)(dian)流(liu)是(shi)(shi)(shi)(shi)(shi)平(ping)衡(heng)的(de)(de)(de)(de)，则应考虑是(shi)(shi)(shi)(shi)(shi)否有过(guo)(guo)(guo)载或(huo)突变，如电(dian)(dian)(dian)(dian)机堵转等。在负(fu)(fu)载惯性较大时，可(ke)适当延长加速(su)时间，此过(guo)(guo)(guo)程(cheng)对变频(pin)(pin)(pin)器(qi)(qi)本身(shen)并无损(sun)坏(huai)。若(ruo)跳闸(zha)时的(de)(de)(de)(de)电(dian)(dian)(dian)(dian)流(liu)，在变频(pin)(pin)(pin)器(qi)(qi)的(de)(de)(de)(de)额(e)定(ding)电(dian)(dian)(dian)(dian)流(liu)或(huo)在电(dian)(dian)(dian)(dian)子(zi)(zi)热(re)继电(dian)(dian)(dian)(dian)器(qi)(qi)的(de)(de)(de)(de)设(she)定(ding)范围内，可(ke)判断是(shi)(shi)(shi)(shi)(shi)IGBT模(mo)块或(huo)相(xiang)关(guan)部分发生(sheng)故(gu)障(zhang)(zhang)(zhang)。首先(xian)可(ke)以通(tong)过(guo)(guo)(guo)测量(liang)变频(pin)(pin)(pin)器(qi)(qi)的(de)(de)(de)(de)主回路(lu)输出端(duan)(duan)子(zi)(zi)U、V、W，分别与直流(liu)侧的(de)(de)(de)(de)P、N端(duan)(duan)子(zi)(zi)之间的(de)(de)(de)(de)正反向电(dian)(dian)(dian)(dian)阻(zu)，来判断IGBT模(mo)块是(shi)(shi)(shi)(shi)(shi)否损(sun)坏(huai)。如模(mo)块未(wei)损(sun)坏(huai)，则是(shi)(shi)(shi)(shi)(shi)驱(qu)动(dong)电(dian)(dian)(dian)(dian)路(lu)出了故(gu)障(zhang)(zhang)(zhang)。如果减速(su)时IGBT模(mo)块过(guo)(guo)(guo)流(liu)或(huo)变频(pin)(pin)(pin)器(qi)(qi)对地短路(lu)跳闸(zha)，一(yi)般是(shi)(shi)(shi)(shi)(shi)逆变器(qi)(qi)的(de)(de)(de)(de)上半(ban)桥的(de)(de)(de)(de)模(mo)块或(huo)其驱(qu)动(dong)电(dian)(dian)(dian)(dian)路(lu)故(gu)障(zhang)(zhang)(zhang)；而加速(su)时IGBT模(mo)块过(guo)(guo)(guo)流(liu)，则是(shi)(shi)(shi)(shi)(shi)下(xia)半(ban)桥的(de)(de)(de)(de)模(mo)块或(huo)其驱(qu)动(dong)电(dian)(dian)(dian)(dian)路(lu)部分故(gu)障(zhang)(zhang)(zhang)，发生(sheng)这些(xie)故(gu)障(zhang)(zhang)(zhang)的(de)(de)(de)(de)原因(yin)，多是(shi)(shi)(shi)(shi)(shi)由(you)于(yu)外部灰尘进(jin)入(ru)变频(pin)(pin)(pin)器(qi)(qi)内部或(huo)环(huan)境(jing)潮湿引(yin)起。

3、控制回路故障分析

      控制回路影响变频器(qi)(qi)寿(shou)命的(de)是电(dian)(dian)源部(bu)分，是平滑电(dian)(dian)容器(qi)(qi)和IGBT电(dian)(dian)路板(ban)中的(de)缓冲电(dian)(dian)容器(qi)(qi)，其(qi)原理与前述相同，但这里(li)的(de)电(dian)(dian)容器(qi)(qi)中通过的(de)脉动电(dian)(dian)流(liu)，是基本不受主回路负(fu)载影响的(de)定值(zhi)，故其(qi)寿(shou)命主要由温(wen)度(du)和通电(dian)(dian)时间决(jue)定。由于(yu)电(dian)(dian)容器(qi)(qi)都焊(han)接在(zai)电(dian)(dian)路板(ban)上，通过测量(liang)静(jing)电(dian)(dian)容量(liang)来判(pan)断(duan)劣化情况比较困难，一般根据电(dian)(dian)容器(qi)(qi)环(huan)境(jing)温(wen)度(du)以(yi)及使用时间，来推算是否接近(jin)其(qi)使用寿(shou)命。

      电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)电(dian)(dian)(dian)(dian)(dian)路(lu)(lu)板(ban)给控制回(hui)路(lu)(lu)、IGBT驱(qu)动电(dian)(dian)(dian)(dian)(dian)路(lu)(lu)和表面(mian)操作(zuo)显示板(ban)以及风扇等(deng)提供电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)，这些(xie)电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)一般(ban)(ban)都是从(cong)主电(dian)(dian)(dian)(dian)(dian)路(lu)(lu)输(shu)出(chu)的(de)直流(liu)电(dian)(dian)(dian)(dian)(dian)压，通过(guo)开(kai)关(guan)(guan)电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)再分(fen)别(bie)整流(liu)而(er)得(de)到(dao)的(de)。因此(ci)，某一路(lu)(lu)电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)短(duan)路(lu)(lu)，除了本路(lu)(lu)的(de)整流(liu)电(dian)(dian)(dian)(dian)(dian)路(lu)(lu)受(shou)损外，还可能影响(xiang)其他部(bu)分(fen)的(de)电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)，如由于误操作(zuo)而(er)使控制电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)与公(gong)共接地(di)短(duan)接，致(zhi)使电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)电(dian)(dian)(dian)(dian)(dian)路(lu)(lu)板(ban)上(shang)开(kai)关(guan)(guan)电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)部(bu)分(fen)损坏(huai)，风扇电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)的(de)短(duan)路(lu)(lu)导致(zhi)其他电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)断电(dian)(dian)(dian)(dian)(dian)等(deng)。一般(ban)(ban)通过(guo)观察电(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)电(dian)(dian)(dian)(dian)(dian)路(lu)(lu)板(ban)就比较容(rong)易(yi)发(fa)现。

      逻(luo)辑(ji)控制电路(lu)板是变频器(qi)的核(he)心，它(ta)集中(zhong)了(le)CPU、MPU、RAM、EEPROM等大规模集成电路(lu)，具有很高的可靠性，本身出现故障的概率很小(xiao)，但有时会因(yin)开机而(er)使全部控制端(duan)子(zi)同(tong)时闭合(he)，导致变频器(qi)出现EEPROM故障，这(zhei)只(zhi)要(yao)对EEPROM重新复位就可以了(le)。

      IGBT电路(lu)板包(bao)含驱动(dong)和缓冲电路(lu)，以及过电压、缺相等保(bao)护电路(lu)。从逻辑(ji)控制板来(lai)的PWM信号，通过光(guang)耦合将电压驱动(dong)信号输(shu)入IGBT模(mo)块(kuai)，因而在检测模(mo)快的同(tong)时，还(hai)应测量IGBT模(mo)块(kuai)上的光(guang)耦。

4、冷却系统

      冷却系统(tong)主(zhu)要包括散热片和冷却风(feng)(feng)(feng)扇。其中(zhong)冷却风(feng)(feng)(feng)扇寿命(ming)较短，临近使用寿命(ming)时(shi)，风(feng)(feng)(feng)扇产(chan)生震动，噪(zao)声增大最后(hou)停转(zhuan)(zhuan)，变频器出现IGBT过热跳闸。冷却风(feng)(feng)(feng)扇的(de)寿命(ming)受陷于轴(zhou)承，大约为10000～35000h。当变频器连续运(yun)转(zhuan)(zhuan)时(shi)，需要2～3年更换一次风(feng)(feng)(feng)扇或轴(zhou)承。为了延长风(feng)(feng)(feng)扇的(de)寿命(ming)，一些产(chan)品(pin)的(de)风(feng)(feng)(feng)扇只在变频器运(yun)转(zhuan)(zhuan)时(shi)而不是电源开启时(shi)运(yun)行。

5、外部的电磁感应干扰

      如果变频(pin)器(qi)(qi)(qi)周(zhou)围存在干扰(rao)源(yuan)，它们将通过辐射或(huo)电(dian)(dian)(dian)(dian)源(yuan)线(xian)(xian)侵入(ru)变频(pin)器(qi)(qi)(qi)的(de)内(nei)部，引(yin)起控(kong)(kong)制回路(lu)误动(dong)(dong)作，造(zao)成工作不正(zheng)常(chang)或(huo)停机(ji)，严重时甚至损(sun)坏变频(pin)器(qi)(qi)(qi)。减(jian)少噪声(sheng)干扰(rao)的(de)具(ju)体方法有(you)：变频(pin)器(qi)(qi)(qi)周(zhou)围所有(you)继电(dian)(dian)(dian)(dian)器(qi)(qi)(qi)、接(jie)(jie)触器(qi)(qi)(qi)的(de)控(kong)(kong)制线(xian)(xian)圈上(shang)(shang)，加(jia)装(zhuang)防止冲击(ji)电(dian)(dian)(dian)(dian)压的(de)吸收装(zhuang)置(zhi)，如RC浪涌吸收器(qi)(qi)(qi)，其接(jie)(jie)线(xian)(xian)不能(neng)超(chao)过20cm；尽量缩短控(kong)(kong)制回路(lu)的(de)5mm以上(shang)(shang)，与主(zhu)回路(lu)保持10cm以上(shang)(shang)的(de)间距(ju)；变频(pin)器(qi)(qi)(qi)距(ju)离电(dian)(dian)(dian)(dian)动(dong)(dong)机(ji)很远(yuan)时（超(chao)过100m），这时一(yi)方面可加(jia)大导线(xian)(xian)截面面积，保证线(xian)(xian)路(lu)压降在2%以内(nei)，同时应加(jia)装(zhuang)变频(pin)器(qi)(qi)(qi)输(shu)出电(dian)(dian)(dian)(dian)抗器(qi)(qi)(qi)，用(yong)(yong)来补偿因长距(ju)离导线(xian)(xian)产生的(de)分布电(dian)(dian)(dian)(dian)容的(de)充(chong)电(dian)(dian)(dian)(dian)电(dian)(dian)(dian)(dian)流。变频(pin)器(qi)(qi)(qi)接(jie)(jie)地端(duan)子应按规定进行(xing)接(jie)(jie)地，必须在专用(yong)(yong)接(jie)(jie)地点(dian)可靠接(jie)(jie)地，不能(neng)同电(dian)(dian)(dian)(dian)焊、动(dong)(dong)力接(jie)(jie)地混用(yong)(yong)；变频(pin)器(qi)(qi)(qi)输(shu)入(ru)端(duan)安(an)装(zhuang)无(wu)线(xian)(xian)电(dian)(dian)(dian)(dian)噪声(sheng)滤波(bo)(bo)器(qi)(qi)(qi)，减(jian)少输(shu)入(ru)高次谐(xie)波(bo)(bo)，从(cong)而可降低从(cong)电(dian)(dian)(dian)(dian)源(yuan)线(xian)(xian)到电(dian)(dian)(dian)(dian)子设备的(de)噪声(sheng)影响；同时在变频(pin)器(qi)(qi)(qi)的(de)输(shu)出端(duan)也安(an)装(zhuang)无(wu)线(xian)(xian)电(dian)(dian)(dian)(dian)噪声(sheng)滤波(bo)(bo)器(qi)(qi)(qi)，以降低其输(shu)出端(duan)的(de)线(xian)(xian)路(lu)噪声(sheng)。

检测方法：

1、判断极性

      首(shou)先将万(wan)用(yong)表(biao)拨在R&TImes;1KΩ挡(dang)，万(wan)用(yong)表(biao)测(ce)量时，若某(mou)一极(ji)(ji)与其(qi)它(ta)两极(ji)(ji)阻值为(wei)无(wu)穷(qiong)大，调(diao)换表(biao)笔(bi)后该(gai)极(ji)(ji)与其(qi)它(ta)两极(ji)(ji)的(de)阻值仍为(wei)无(wu)穷(qiong)大，则判断(duan)此极(ji)(ji)为(wei)栅(zha)极(ji)(ji)（G ）其(qi)余两极(ji)(ji)再(zai)用(yong)万(wan)用(yong)表(biao)测(ce)量，若测(ce)得阻值为(wei)无(wu)穷(qiong)大，调(diao)换表(biao)笔(bi)后测(ce)量阻值较小。在测(ce)量阻值较小的(de)一次(ci)中，则判断(duan)红表(biao)笔(bi)接(jie)的(de)为(wei)集电极(ji)(ji)（C）;黑表(biao)笔(bi)接(jie)的(de)为(wei)发射极(ji)(ji)（E）。

2、判断好坏

      将万用表拨在R&TImes;10KΩ挡，用黑表笔(bi)接(jie)IGBT 的(de)集(ji)电(dian)极(ji)(ji)(ji)（C），红(hong)表笔(bi)接(jie)IGBT 的(de)发(fa)射极(ji)(ji)(ji)（E），此时(shi)万用表的(de)指针(zhen)在零(ling)位。用手指同时(shi)触及一(yi)下栅极(ji)(ji)(ji)（G）和(he)集(ji)电(dian)极(ji)(ji)(ji)（C），这时(shi)IGBT 被触发(fa)导通，万用表的(de)指针(zhen)摆向阻(zu)值较小的(de)方向，并能(neng)站住指示(shi)在某一(yi)位置。然后再用手指同时(shi)触及一(yi)下栅极(ji)(ji)(ji)（G）和(he)发(fa)射极(ji)(ji)(ji)（E），这时(shi)IGBT 被阻(zu)断(duan)，万用表的(de)指针(zhen)回零(ling)。此时(shi)即可判断(duan)IGBT 是(shi)好的(de)。

3、检测注意事项

      任何(he)指针(zhen)式万用(yong)表皆可用(yong)于检测IGBT。注意判(pan)断(duan)IGBT 好坏时(shi)，一(yi)定要(yao)将万用(yong)　表拨在(zai)R&TImes;10KΩ挡，因R&TImes;1KΩ挡以下各档万用(yong)表内部电(dian)(dian)池电(dian)(dian)压(ya)太低(di)，检测好坏时(shi)不能使IGBT 导(dao)通，而无法(fa)判(pan)断(duan)IGBT 的(de)好坏。此方法(fa)同(tong)样也可以用(yong)于检测功率场效(xiao)应(ying)晶体管（P-MOSFET）的(de)好坏。

以(yi)上就是今天小编(bian)要讲(jiang)的所(suo)有内容啦，大家有任何问题(ti)可留言给我们哦~

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