问题 问答题

对无压检定和同步检定重合闸,为什么在无压侧还要投入同步检定继电器?为什么无压侧和同步侧要定期轮换?

答案

参考答案:

(1)如果由于误碰或继电保护误动作使某一侧的断路器误跳闸,则可以通过同步检定继电器检查两侧电源同步进行重合闸,因此在无压侧还要投入同步检定继电器。

(2)为了使两侧断路器的切除短路电流的次数(或工作条件)趋于平衡,在同步侧也装设了无压检定继电器,两侧的无压连接片定期切换使无压侧和同步侧定期轮换。

阅读理解

There was once a professor of medicine, who was very strict with the students. Whenever he took the chair on the exam committee(担任考试委员会 * * ), the students would be in fear, because he was seldom pleased with the answers they gave. A student would be lucky enough if he or she could receive a good mark from him. At the end of the term, the students of medicine would take their exam again. Now a student entered the exam room and got seated before the committee. This student was a little nervous as he knew it would not be so easy to get through the exam at all.

The professor began to ask. The student was required to describe a certain illness, his description of which turned out to be OK.

  Then the professor asked about the cure (药剂) for illness, and the student, too, answered just as right.

“Good,” said the professor, “and how much will you give the patient?”

“A full spoon”, answered the student.

“Now you may go out and wait for what you can get.”, said the professor. At the same time, the committee discussed carefully the answers the student had given. Suddenly the student noticed that there was something wrong with his last answer. “ A full spoon is too much,” he thought to himself. Anxiously he opened the door of the room and cried, “Mr. Professor, I’ve made a mistake! A full spoon is too much for a patient. He can take only five drops.”

“I’m sorry, sir.” said the professor coldly, “But it’s too late. Your patient has died.”

小题1:The students were afraid of the professor because_________.

A.they often angered and disappointed him

B.their answers often astonished him

C.their answers seldom satisfied him

D.he often misunderstood them and gave them bad marks小题2: The student’s description of the illness was           .

A.not correct

B.not satisfied

C.completely discouraging

D.accepted.小题3:Before he left the room the student was almost sure that          .

A.he had passed the exam, and the only thing was to wait for the mark

B.his last answer was satisfying

C.he had made a mistake

D.he had not done well in the exam.小题4:Which of the following is Not true?

A.The patient will be in danger if he’s taken as much as a full spoon.

B.The doctor will be in trouble if he’s given the patient a full spoon.

C.Since one spoon is less than five drops, the patient will be all right soon if he takes only one full spoon at a time.

D.If the patient wants to remain safe, he should take no more than five drops at a time.

填空题