某220kV变电所,原有2台120MVA主变压器,其电压为220/110/35kV,

题型:单项选择题

问题:

某220kV变电所,原有2台120MVA主变压器,其电压为220/110/35kV,220kV为户外管母线中型布置,管母线规格为Φ100/90;220kV、110kV为双母线接线,35kV为单母线分段接线,根据负荷增长的要求,计划将现有2台主变压器更换为180MVA(远景按3×180MVA考虑)。

该变电所选择220kV母线三相短路电流为38kA,若180MVA主变压器阻抗,110kV侧、35kV侧均为开环且无电源,请计算该变电所110kV母线最大三相短路电流为下列哪项数值?(SB=100MVA,UB=230/121kV)()

A.5.65kA

B.8.96kA

C.10.49kA

D.14.67kA

考点:注册电气工程师发输变电专业注册电气工程师发输变电专业2010年(上)专业案例真题(案例题(选择题))
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__小题1:__ Make a study time and have it at the same time every day.This will help your kids to learn to schedule their day and will give them a sense of control over how they spend their time.

Allow them to study in blocks of time,such as for half an hour with a five­minute break in the middle.__小题2:__ Ideal(理想的) study times are after dinner or right after school before dinner.

Never allow your children to study in front of the television,as that will encourage passive activity(被动活动).__小题3:__

You'll also need to help your kids find the right place to study.After you've set up a good study time for little learners,set up a good place where they can get those creative juices flowing.

__小题4:__ Make sure there is a table or a desk and a comfortable chair.

__小题5:__ This includes helping them out with their homework sometimes and being there for them with the answers to any questions.The input(投入) you give your children during study periods will help form a bond(结合,联系) and help make studying enjoyable.

A.Pick a place where your children can study properly.

B.Hold them to the schedule they create for themselves.

C.Finally,spend time with your kids when they're studying.

D.Keep the atmosphere(氛围) light and offer lots of encouragement,too.E.Instead,use TV as a treat or a reward when the homework is completed.

F.Try to stop this bad habit by offering some sort of reward.

G.One of the best ways to form good study habits for your kids is to design a schedule(计划) that they keep to.

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