當市電(dian)(dian)(dian)供(gong)電(dian)(dian)(dian)中斷或(huo)市電(dian)(dian)(dian)電(dian)(dian)(dian)壓超限(xian) (±15%或(huo)±20%額(e)定輸入電(dian)(dian)(dian)壓)時(shi),互投裝置將立即投切至逆變器供(gong)電(dian)(dian)(dian),在電(dian)(dian)(dian)池組所提(ti)供(gong)的直流能源(yuan)(yuan)的支持下,此時(shi),用戶負載(zai)所使用的電(dian)(dian)(dian)源(yuan)(yuan)是通過EPS的逆變器轉換的交流電(dian)(dian)(dian)源(yuan)(yuan),而不(bu)是來自市電(dian)(dian)(dian)