问题 问答题

RCS-915AB母线保护装置的母联死区保护是如何实现的?

答案

参考答案:

若母联开关和母联TA之间发生故障,断路器侧母线跳开后故障仍然存在,正好处于TA侧母线小差的死区,为提高保护动作速度,专设了母联死区保护。RCS-915AB母线保护装置的母联死区保护在差动保护发母线跳令后,母联开关已跳开而母联TA仍有电流,且大差比率差动元件及断路器侧小差比率差动元件不返回的情况下,经死区动作延时Tsq跳开另一条母线。为防止母联在跳位时发生死区故障将母线全切除,当两母线都有电压且母联在跳位时母联电流不计入小差。

问答题
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Roger Conner is a modern­-day Horatio Alger hero. Roger started out as an unpaid worker in a small flower shop. He has become the owner of a florist company whose sales are well over $100 000 a year.

One day when Roger was only twelve, he stopped at a local flower shop. He asked the owner if he could work for him, without pay, in order to learn the business. Roger started working every day after school and on weekends. After two years on the job, he finally asked for a small salary. The owners told him he “wasn't good enough to be paid.” So he quit, and found a paying job at another local flower shop. He worked hard there, but after six months they laid him off because business was slow.

Not discouraged, Roger decided to do it alone and started his own flower store in a basement in his town. He started his business with only sixty­-five dollars. He bought old refrigerators at garage sales and knocked the shelves out. This turned them into coolers for his fresh­-cut flowers. His business grew rapidly as he built up a reputation for top quality and fine service.

In 1977, Roger bought out the flower store where he had worked without pay for over two years. The people who said he “wasn’t good enough to be paid” were astonished to find that they were being taken over by a teenager. He had plans to renovate (振兴) the whole store.

One of the reasons the owners sold out to Roger was that the store wasn't doing well. But after Roger took over ownership and redid the store, business started booming. In fact, business was so good that after one year, he celebrated by buying out the other store where he had worked. Roger then combined both stores and moved to a location in the center of his town.

The new store has 2 000 square feet and seven employees. And he did it all before he reached the age of twenty.

小题1:The author is wants to show us that people who want to succeed in business should ________.

A.work without pay

B.own a flower shop

C.work hard and never give up

D.work as teenagers小题2:Which of the following is NOT true according to the passage?

A.He worked for two years without pay.

B.He needed luck to be successful.

C.He opened his first flower business in a basement.

D.He became successful before the age of twenty.小题3:The passage may be a ________.

A.newspaper report

B.humorous story

C.television play

D.scientific story小题4:The underlined part in Paragraph 2 probably means ________.

A.employed him

B.didn’t let him work there

C.paid him money

D.were proud of him小题5:From the passage, a “Horatio Alger hero” may be the kind of person who________.

A.works hard in the flower business

B.was born into a rich family

C.starts out poor and becomes rich

D.becomes famous as a result of good luck