问题 问答题 简答题

电机升不起电压现象及处理?

答案

参考答案:

①.现象:

a.发电机升压时定子电压表无指示或接近于零,转子电流、电压有指示;

b.发电机升压时定子电压表转子电流、电压均无指示;

②.处理:

①.检查发电机定子电压表、励磁电流表、励磁电流表指示是否正常;

②.碳刷与滑环是否接触良好,有无环火;

③.检查发电机PT回路是否有故障;

④.检查整流柜是否投入正常;

⑤.检查励磁回路是否有短路、断线以及极性接反现象;

⑥.励磁调节柜是否正常,励磁调节方式是否正常;

⑦.起励电源是否正常;

⑧.通知检修处理。

补全对话,情景问答

根据所给语境,选择适当的答案。

1. 当你上学迟到时,你可以这样对老师说:[ ]

A. It doesn't matter.

B. I'm sorry. I'm late.

C. That's all right.

2. 当别人对你说 " What's your job? ” 你可以说: [ ]

A. I'm Kate.

B. I'm a doctor.

C. I'm Li Ming's mother.

3. 当别人对你说“Let's go skating!”,你不想去可以说:[ ]

A. Sorry, I am busy.

B. OK, let's go.

C. That's a good idea.

4. 当你的朋友说“I've got a bad cough.”,你可以说:[ ]

A. How are you?

B. I'm sorry to hear that.

C. How do you do?

5. 开学后,老师第一次见到同学们,会说:[ ]

A. What's your name?

B. Welcome back to school, boys and girls.

C. Goodbye boys and girls.

6. 你想知道有多少把椅子,可以说:[ ]

A. How many chairs do you have?

B. How many chair do you have?

C. Where are the chairs?

7. 您想告诉别人“今天是星期一”时,可以说:[ ]

A. Today is Monday.

B. Today is Tuesday.

C. What day is today?

8. 你想对别人说“对不起”,可以说:[ ]

A. Thank you.

B. Sorry.

C. Goodbye.

9. 你想让别人看大象,应该说:[ ]

A. Look at the elephant.

B. Look the elephant.

C. Look after the elephant.

10. 你想问别人,“你在哪儿”时,应该说:[ ]

A. When are you?

B. Where are you?

C. What are you?

11. 你想对一个熟人打招呼,应该说:[ ]

A. How do you do?

B. Where are you?

C. Hello!

12. 下午与朋友见面时,应该说:[ ]

A. Good morning.

B. Good afternoon.

C. Good evening.

13. 你有事麻烦别人,可以说:[ ]

A. Excuse me.

B. You're welcome.

C. I'm sorry.

14. 你想说“我有6支铅笔”时,应该说:[ ]

A. I have six pencils.

B. I have six pen.

C. There're six pencils.

15. 你想告诉别人“我很高”时,应该说:[ ]

A. I'm tall.

B. I was tall.

C. I am short.

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