问题
单项选择题
有1台10kV,800kW异步电动机,cos=0.8,起动电流倍数为10,可自起动,系统接地电流为15A,10kV母线短路容量为200MV·A(最小方式),请列出保护配置,选择电流互感器变比,并计算保护动作电流、短路电流和灵敏系数。
与仪表共用电流互感器的变流比为()。
A.50A/5A
B.75A/5A
C.100A/5A
D.150A/5A
答案
参考答案:B
有1台10kV,800kW异步电动机,cos=0.8,起动电流倍数为10,可自起动,系统接地电流为15A,10kV母线短路容量为200MV·A(最小方式),请列出保护配置,选择电流互感器变比,并计算保护动作电流、短路电流和灵敏系数。
与仪表共用电流互感器的变流比为()。
A.50A/5A
B.75A/5A
C.100A/5A
D.150A/5A
参考答案:B
阅读下面短文,根据短文内容完成表格中所缺信息,每空一词。(共10小题,每小题1分,计10分)友情提醒:请将答案用蓝色、黑色钢笔或圆珠笔直接写在答题纸上。 Andy was born in China 17 years ago. In 2007, she went to the USA with her family. As a high school student, she has found many differences between Chinese and Americans: About money Americans like to spend more than they have, so many of them are always in debt(欠债). But Chinese usually spend less than they have, so many of them always have money left in the bank. The American kids themselves make their own money. Most Chinese kids always ask their parents for money. About friends Most American parents let their sons or daughters make friends by themselves. They never ask them about their friends while Chinese parents usuaolly enjoy knwing more about their children’s friends in many different ways, and usually stop them from staying out too late with friends. About education Many American students have less homework to do while many Chinese students have much. Many American girls take part in sports, dancing and singing groups while many Chinese girls take part in study groups. Many American parents think there is no need to send their children to an expensive school. It’s different in China. Many Chinese parents would do anything to send their children to expensive schools though their family isn’t rich enough.
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