當市(shi)電(dian)(dian)(dian)供(gong)電(dian)(dian)(dian)中斷或市(shi)電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)超限(xian) (±15%或±20%額定輸入電(dian)(dian)(dian)壓(ya))時(shi),互投(tou)裝置將(jiang)立(li)即投(tou)切至(zhi)逆(ni)變器供(gong)電(dian)(dian)(dian),在電(dian)(dian)(dian)池組所提供(gong)的直流(liu)能源的支持(chi)下,此時(shi),用戶(hu)負載(zai)所使(shi)用的電(dian)(dian)(dian)源是通過EPS的逆(ni)變器轉換的交流(liu)電(dian)(dian)(dian)源,而不是來(lai)自市(shi)電(dian)(dian)(dian)