由于電(dian)(dian)力電(dian)(dian)子器(qi)件(jian)(jian)工(gong)作(zuo)狀態有開通、通態、關(guan)(guan)(guan)斷(duan)、斷(duan)態四種工(gong)作(zuo)狀態，其(qi)中斷(duan)態、通態分別承受高電(dian)(dian)壓(ya)(ya)、大(da)電(dian)(dian)流(liu)(liu)，而(er)開通和關(guan)(guan)(guan)斷(duan)的(de)過(guo)(guo)程中，開關(guan)(guan)(guan)器(qi)件(jian)(jian)可能同時承受過(guo)(guo)壓(ya)(ya)過(guo)(guo)流(liu)(liu)、過(guo)(guo)大(da)的(de)di/dt、du/dt以及過(guo)(guo)大(da)的(de)瞬時功(gong)率。所以為了(le)(le)防(fang)止高電(dian)(dian)壓(ya)(ya)大(da)電(dian)(dian)流(liu)(liu)使器(qi)件(jian)(jian)工(gong)作(zuo)點超出安全工(gong)作(zuo)區(qu)而(er)損(sun)壞器(qi)件(jian)(jian)，就在(zai)電(dian)(dian)路(lu)中加入了(le)(le)緩(huan)沖電(dian)(dian)路(lu)，關(guan)(guan)(guan)斷(duan)緩(huan)沖電(dian)(dian)路(lu)吸收器(qi)件(jian)(jian)的(de)關(guan)(guan)(guan)斷(duan)過(guo)(guo)電(dian)(dian)壓(ya)(ya)和換(huan)相過(guo)(guo)電(dian)(dian)壓(ya)(ya)，抑制(zhi)du/dt，減(jian)小關(guan)(guan)(guan)斷(duan)損(sun)耗；而(er)開通緩(huan)沖電(dian)(dian)路(lu)抑制(zhi)器(qi)件(jian)(jian)開通時的(de)電(dian)(dian)流(liu)(liu)過(guo)(guo)沖和di/dt，減(jian)小器(qi)件(jian)(jian)的(de)開通損(sun)耗。
    在(zai)現代生活中，IGBT作為(wei)全(quan)控型器件得到了越來越廣泛的(de)應用，隨(sui)著其(qi)功率和(he)電壓等級的(de)不斷提高(gao)，對(dui)它的(de)保護就顯得尤為(wei)重要(yao)。IGBT在(zai)關斷時出現的(de)尖(jian)(jian)峰電壓主要(yao)是(shi)由于(yu)主回(hui)路中分布電感(gan)的(de)存(cun)在(zai)引(yin)起的(de)，過高(gao)的(de)尖(jian)(jian)峰電壓不僅會損壞IGBT，也可能導(dao)致IGBT誤導(dao)通，所以(yi)設置緩沖電路以(yi)吸收尖(jian)(jian)峰電壓是(shi)必(bi)不可少(shao)的(de)。
以下是(shi)在(zai)逆變器采用兩(liang)電(dian)(dian)平和(he)三(san)電(dian)(dian)平兩(liang)種拓(tuo)撲結構的緩沖(chong)電(dian)(dian)路。