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電(dian)(dian)(dian)解電(dian)(dian)(dian)容(rong)廣(guang)泛應用在電(dian)(dian)(dian)力電(dian)(dian)(dian)子的不同(tong)領域，主要是(shi)用于(yu)平滑、儲存能量或者交流電(dian)(dian)(dian)壓整(zheng)流后的濾波，另外還用于(yu)非(fei)精密的時序(xu)延時等。在開關(guan)電(dian)(dian)(dian)源的MTBF預計時，模型分析(xi)結果表明電(dian)(dian)(dian)解電(dian)(dian)(dian)容(rong)是(shi)影響(xiang)開關(guan)電(dian)(dian)(dian)源壽命(ming)的主要因素，因此了解、影響(xiang)電(dian)(dian)(dian)容(rong)壽命(ming)的因素非(fei)常重要。

1.電解電容的壽命取決于其內部溫度(du)。

因此，電(dian)(dian)解(jie)電(dian)(dian)容的(de)(de)設(she)計和應(ying)用(yong)條件都(dou)會影響到電(dian)(dian)解(jie)電(dian)(dian)容的(de)(de)壽命(ming)。從(cong)設(she)計角度，電(dian)(dian)解(jie)電(dian)(dian)容的(de)(de)設(she)計方法、材料、加工工藝決(jue)定了電(dian)(dian)容的(de)(de)壽命(ming)和穩定性。而對(dui)應(ying)用(yong)者來講，使(shi)用(yong)電(dian)(dian)壓、紋波電(dian)(dian)流(liu)、開(kai)關頻率、安裝形式、散熱(re)方式等都(dou)影響電(dian)(dian)解(jie)電(dian)(dian)容的(de)(de)壽命(ming)。

2.電(dian)解電(dian)容的非(fei)正(zheng)常失效

一些因素(su)會引(yin)起電(dian)解(jie)電(dian)容(rong)失效，如極低(di)的溫(wen)(wen)(wen)度，電(dian)容(rong)溫(wen)(wen)(wen)升(sheng)（焊接溫(wen)(wen)(wen)度，環境溫(wen)(wen)(wen)度，交流紋波），過高(gao)的電(dian)壓(ya)，瞬(shun)時(shi)電(dian)壓(ya)，甚高(gao)頻或(huo)反偏壓(ya)；其(qi)中(zhong)溫(wen)(wen)(wen)升(sheng)是對電(dian)解(jie)電(dian)容(rong)工作壽命(Lop)影響最(zui)大的因素(su)。

電容(rong)的導電能(neng)力由電解(jie)液的電離(li)能(neng)力和粘(zhan)度決定(ding)。當溫度降低(di)(di)時(shi)，電解(jie)液粘(zhan)度增加(jia)(jia)，因而離(li)子移動(dong)性和導電能(neng)力降低(di)(di)。當電解(jie)液冷凍時(shi)，離(li)子移動(dong)能(neng)力非常低(di)(di)以致非常高(gao)的電阻。相反，過高(gao)的熱量(liang)將加(jia)(jia)速電解(jie)液蒸發，當電解(jie)液的量(liang)減少(shao)到一(yi)定(ding)極限(xian)時(shi)，電容(rong)壽(shou)命也(ye)就終止(zhi)了。在高(gao)寒地區（一(yi)般－25℃以下）工作(zuo)時(shi)，就需要進行加(jia)(jia)熱，保(bao)證電解(jie)電容(rong)的正常工作(zuo)溫度。如室(shi)外(wai)型UPS，在我國東(dong)北地區都配有加(jia)(jia)熱板。

電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器在過壓(ya)(ya)狀態(tai)下容(rong)(rong)(rong)易被擊穿，而實際應用中的(de)浪(lang)涌電(dian)(dian)(dian)(dian)壓(ya)(ya)和瞬時高電(dian)(dian)(dian)(dian)壓(ya)(ya)是(shi)(shi)(shi)經常(chang)出(chu)(chu)現的(de)。尤(you)其(qi)我國幅員遼闊，各(ge)地電(dian)(dian)(dian)(dian)網(wang)(wang)復雜，因此，交流(liu)電(dian)(dian)(dian)(dian)網(wang)(wang)很(hen)復雜，經常(chang)會(hui)出(chu)(chu)現超出(chu)(chu)正(zheng)常(chang)電(dian)(dian)(dian)(dian)壓(ya)(ya)的(de)30%，尤(you)其(qi)是(shi)(shi)(shi)單相輸(shu)入，相偏(pian)會(hui)加重交流(liu)輸(shu)入的(de)正(zheng)常(chang)范圍。經測試表明，常(chang)用的(de)450V/470uF105℃的(de)進口(kou)普(pu)通(tong)2000小時電(dian)(dian)(dian)(dian)解電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)，在額定電(dian)(dian)(dian)(dian)壓(ya)(ya)的(de)1.34倍電(dian)(dian)(dian)(dian)壓(ya)(ya)下，2小時后(hou)電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)會(hui)出(chu)(chu)現漏液冒氣，頂(ding)部沖開(kai)。根據統(tong)計和分析，與電(dian)(dian)(dian)(dian)網(wang)(wang)接(jie)近的(de)通(tong)信(xin)開(kai)關電(dian)(dian)(dian)(dian)源PFC輸(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)解電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)的(de)失效，主要是(shi)(shi)(shi)由于(yu)電(dian)(dian)(dian)(dian)網(wang)(wang)浪(lang)涌和高壓(ya)(ya)損壞。鋁電(dian)(dian)(dian)(dian)解電(dian)(dian)(dian)(dian)容(rong)(rong)(rong)的(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)選擇一般進行二(er)級降額，降到額定值的(de)80％使(shi)用較(jiao)為(wei)合理。

3壽命影響(xiang)因素(su)分析

除了非正常的(de)(de)(de)失效，電(dian)(dian)(dian)解(jie)電(dian)(dian)(dian)容的(de)(de)(de)壽命與溫度(du)有指數級(ji)的(de)(de)(de)關系。因使(shi)用非固態電(dian)(dian)(dian)解(jie)液(ye)(ye)，電(dian)(dian)(dian)解(jie)電(dian)(dian)(dian)容的(de)(de)(de)壽命還取決于電(dian)(dian)(dian)解(jie)液(ye)(ye)的(de)(de)(de)蒸發速度(du)，由此導致的(de)(de)(de)電(dian)(dian)(dian)氣性能降低。這些參數包括電(dian)(dian)(dian)容的(de)(de)(de)容值(zhi)，漏電(dian)(dian)(dian)流和等效串聯電(dian)(dian)(dian)阻（ESR）。

參考RIFA公司預計壽命的(de)公式：

PLOSS=(IRMS)2xESR（1）

Th=Ta+PLOSSxRth（2）

Lop=Ax2Hours（3）

B=參(can)考溫(wen)度值（典型值為(wei)85℃）

A=參考溫度下的電(dian)容壽(shou)命（根據電(dian)容器(qi)直徑的不同(tong)而變化）

C=導致電容(rong)壽(shou)命減少一半所需的溫升度(du)數

從上面的(de)(de)(de)公式中，我們(men)可以明顯的(de)(de)(de)看到(dao)，影(ying)響電(dian)(dian)解電(dian)(dian)容(rong)壽命(ming)(ming)的(de)(de)(de)幾個直接因素(su)：紋波電(dian)(dian)流(liu)(IRMS)和(he)等效串聯電(dian)(dian)阻(zu)值（ESR）、環(huan)境(jing)(jing)溫(wen)(wen)(wen)(wen)度（Ta）、從熱(re)點傳(chuan)遞到(dao)周(zhou)圍環(huan)境(jing)(jing)的(de)(de)(de)總的(de)(de)(de)熱(re)阻(zu)（Rth）。電(dian)(dian)容(rong)內部(bu)溫(wen)(wen)(wen)(wen)度最高的(de)(de)(de)點，叫熱(re)點溫(wen)(wen)(wen)(wen)度（Th）。熱(re)點溫(wen)(wen)(wen)(wen)度值是影(ying)響電(dian)(dian)容(rong)工作(zuo)壽命(ming)(ming)的(de)(de)(de)主要因素(su)。而下列因素(su)又決(jue)定了熱(re)點溫(wen)(wen)(wen)(wen)度值實際應(ying)用(yong)中的(de)(de)(de)外界(jie)溫(wen)(wen)(wen)(wen)度（環(huan)境(jing)(jing)溫(wen)(wen)(wen)(wen)度Ta）,從熱(re)點傳(chuan)遞到(dao)周(zhou)圍環(huan)境(jing)(jing)的(de)(de)(de)總的(de)(de)(de)熱(re)阻(zu)（Rth）和(he)由交流(liu)電(dian)(dian)流(liu)引起的(de)(de)(de)能(neng)量(liang)損耗（PLOSS）。電(dian)(dian)容(rong)的(de)(de)(de)內部(bu)溫(wen)(wen)(wen)(wen)升與(yu)能(neng)量(liang)損耗成線形關系(xi)。

電(dian)(dian)(dian)容充(chong)放電(dian)(dian)(dian)時，電(dian)(dian)(dian)流在(zai)流過(guo)電(dian)(dian)(dian)阻時會引(yin)起能(neng)量損(sun)耗(hao)，電(dian)(dian)(dian)壓的(de)變化在(zai)通過(guo)電(dian)(dian)(dian)介質(zhi)時也會引(yin)起能(neng)量損(sun)耗(hao)，再(zai)加上漏(lou)電(dian)(dian)(dian)流造成的(de)能(neng)量損(sun)耗(hao)，所(suo)有的(de)這(zhe)些(xie)損(sun)耗(hao)導致的(de)結果是電(dian)(dian)(dian)容內部溫度升高。