There's going _____ a sports meeting nex 发布时间:2017-05-17 20:51 │ 来源:www.tikuol.com 题型:选择题 问题: There's going _____ a sports meeting next Friday. [ ]A. have B. to have C. to be D. has
题型:选择题 某新建2×300MW燃煤发电厂,高压厂用电系统标称电压为6kV,其中性点为高电阻接地。每台机组设二台高压厂用无励磁调压双绕组变压器,容量为35MVA,阻抗值为10.5%,6.3kV单母线接线,设A段、B段。6kV系统电缆选为ZR-YJV22-6/6KV。已知:当A段母线上容量为3200kW的给水泵电动机起动时,其母线已带负荷19141kVA,求该电动机起动时的母线电压百分数为下列哪项数值?(已知该电动机起动电流倍数为6、额定效率为0.963、功率因数为0.9)()A.88%B.92%C.93%D.97% 查看答案