電(dian)(dian)(dian)(dian)(dian)源有直(zhi)流(liu)和(he)電(dian)(dian)(dian)(dian)(dian)流(liu)之分(fen)，交(jiao)(jiao)流(liu)電(dian)(dian)(dian)(dian)(dian)源是(shi)相對直(zhi)流(liu)電(dian)(dian)(dian)(dian)(dian)源而(er)言(yan)的(de)(de)。常見的(de)(de)交(jiao)(jiao)流(liu)電(dian)(dian)(dian)(dian)(dian)源就是(shi)家庭用(yong)電(dian)(dian)(dian)(dian)(dian)，220V交(jiao)(jiao)流(liu)電(dian)(dian)(dian)(dian)(dian)，電(dian)(dian)(dian)(dian)(dian)流(liu)大(da)小(xiao)、方向會(hui)(hui)隨著(zhu)時間的(de)(de)改變(bian)(bian)而(er)變(bian)(bian)化。交(jiao)(jiao)流(liu)電(dian)(dian)(dian)(dian)(dian)最大(da)的(de)(de)特點(dian)就是(shi)功率大(da)、變(bian)(bian)換和(he)傳輸方便，發(fa)電(dian)(dian)(dian)(dian)(dian)廠供應的(de)(de)電(dian)(dian)(dian)(dian)(dian)都是(shi)交(jiao)(jiao)流(liu)電(dian)(dian)(dian)(dian)(dian)。眾所(suo)知周，電(dian)(dian)(dian)(dian)(dian)源浪(lang)(lang)涌(yong)不僅(jin)僅(jin)源于雷擊(ji)，當電(dian)(dian)(dian)(dian)(dian)力系統出現故障(zhang)、投切大(da)負荷時也會(hui)(hui)產生電(dian)(dian)(dian)(dian)(dian)源浪(lang)(lang)涌(yong)。不管是(shi)雷擊(ji)浪(lang)(lang)涌(yong)還是(shi)電(dian)(dian)(dian)(dian)(dian)源浪(lang)(lang)涌(yong)，都會(hui)(hui)直(zhi)接影(ying)響到電(dian)(dian)(dian)(dian)(dian)路(lu)的(de)(de)正常工(gong)作。為此，電(dian)(dian)(dian)(dian)(dian)源浪(lang)(lang)涌(yong)防(fang)護是(shi)每個電(dian)(dian)(dian)(dian)(dian)子工(gong)程師必須要考慮的(de)(de)。

接下來(lai)，要(yao)分享的是(shi)220V交流AC電(dian)源端口(kou)浪涌保護設(she)計方案圖，如下：

從方案圖中可以看出，方案用于滿足220V交流電源接口的浪涌保護。共模保護的壓敏電阻MOV對地串陶瓷氣體放電管GDT，減緩壓敏電阻的老化，本方案適合中大功率電源。具體型號，要根據電源所處環境應用及測試標準（IEC61000-4-5 4kV-8kV不同級別、GB/T 17626.5、UL1449等等 ）來選擇。

在220V交流AC電源端口浪涌保護方案圖中，需要注意的是：陶瓷氣體放電管(guan)不能直接用于220V輸入交流電源防護中，具體原因有兩點：其一，GDT是開關型防護器件，響應速度較慢，影響系統供電；其二，GDT存在續流問題，動作后，需要很低的電壓就能導通，存在安全風險。對于220V系統來說，第一級共模慮波不推薦單獨使用壓敏電阻，主要因為壓敏電阻老化問題，經過多次泄放后性能會下降；壓敏電阻具有較大的寄生電容，會出現漏電流的情況；壓敏電阻的失效模式是短路失效，失效后會存在風險。

可見，220V交流AC電源端口浪涌保護選用什么類型的防浪涌保護器件以及如何組合，是經過多方面考慮、實踐驗證出來的，更多有關其他電源系統典型應用防護方案，可直接咨詢東沃FAE工程師：136 7581 6901（微信同號）朱工