问题 问答题 论述题

交流系统运行操作的一般规定是什么?

答案

参考答案:

(1)220KV系统倒母线操作采用等电位操作方法,允许用刀闸拉合并联支路电流,在母线倒排操作时,为保证母联开关在合闸位置,应取下母联开关的控制回路保险,操作完毕,立即恢复。

(2)220KV旁路开关代线路开关运行时,采用下列方法:

①将旁路开关保护定值改为与所代线路开关保护定值相同。

②用旁路开关对旁路#4母线充电良好。

③拉开旁路开关,合上旁路所带线路侧-4刀闸对旁路#4母线送电。

④检定同期(非环网线路除外),合上旁路开关与所带线路开关并环,将线路开关停电。

⑤在用旁路带路或恢复原运行方式的倒闸操作中,应将线路侧高频保护停用,同时联系中调停用对侧高频保护,并将本侧零序电流保护停用。

(3)220V线路停电操作时,应先拉开线路开关,再拉开线路侧刀闸,最后拉开母线侧刀闸;送电时应先合上母线侧刀闸,再合上线路侧刀闸,最后合线路开关。

(4)母线送电前,应先投入母线PT;母线停电后再退出母线PT。

(5)刀闸拉合闸操作时,三相刀闸触头应同期,合闸后应检查其一次触头的接触情况,以及二次辅助接点的切换情况。

(6)合接地刀闸前,应检查所属刀闸在断开位置,并进行验电,确定无电压后方能合接地刀闸。合接地刀闸后,应检查三相均接触良好,线路-D3接地刀的拉合操作,应根据调度命令执行。

(7)变压器送电时,应先合高压侧开关,后合低压侧开关,停电时顺序相反。

(8)开关送电时,要在所属刀闸合闸后进行,开关停电后再拉开所属刀闸,不允许用刀闸拉合负荷电流。

阅读理解

阅读理解。

     Good afternoon, everyone! This is Rose Garden Middle School Radio. John Smith speaking, with something new to share with you today. We all know that thinking green is sometimes the most difficult thing to do, but

not impossible! Bed ZED, a new eco-friendly village (生态村) in the south of London, has done a great job of

providing its villagers with a high level living while getting them to pay more attention to protecting the

environment. 

     People in Bed ZED have done many things. They recycle their paper, plastic, glass and other daily things.

They build many houses whose windows face south in order to get as much sunlight as possible. The rainwater

is collected for use in the toilets. Also, the people there travel to work in shared cars or use public transportation if they work far away.

     Now, you may think it's not easy to live such a life, but let me tell you. it's not! It's a way of life. We just

have to say no to what is bad for the environment, and begin working on ideas to protect it. Life would be

much more pleasant if villages like Bed ZED existed (存在) all over the world! Thank you for listening!

1. What people in Bed ZED often do is __________.

A. to build a lot of houses

B. to go to work in their own cars

C. to recycle the paper, plastic and glass

2. In Bed ZED, the water used in the toilet may come from __________.

A. river water

B. running water

C. collected rainwater

3. People in Bed ZED usually go to work __________ if they work far away.

A. by bus

B. on foot

C. by bike

4. The expression "thinking green" might mean the same as __________.

A. building a green house

B. keeping simple thoughts

C. protecting the environment

5. The writer's opinion is that __________.

A. people should be against building eco-friendly villages

B. Bed ZED is a good example in protecting the environment!

C. the idea of thinking green is hard to work on

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