當市電(dian)(dian)(dian)供電(dian)(dian)(dian)中斷或(huo)市電(dian)(dian)(dian)電(dian)(dian)(dian)壓超限 (±15%或(huo)±20%額(e)定輸(shu)入電(dian)(dian)(dian)壓)時,互投裝置將立即(ji)投切至逆變器(qi)供電(dian)(dian)(dian),在電(dian)(dian)(dian)池(chi)組所提供的直流能(neng)源(yuan)(yuan)的支持下,此時,用戶負載所使(shi)用的電(dian)(dian)(dian)源(yuan)(yuan)是通過EPS的逆變器(qi)轉(zhuan)換的交(jiao)流電(dian)(dian)(dian)源(yuan)(yuan),而不是來自(zi)市電(dian)(dian)(dian)