2025年国家电网专业技术人员考试(电力英语)历年参考题库含答案.docxVIP

2025年国家电网专业技术人员考试(电力英语)历年参考题库含答案

PartIVocabularyandStructure(共20小题，每小题1分，满分20分)

1.ThenewlyinstalledSTATCOMcan______reactivepowerwithin5ms,thusstabilizingthe220kVbusvoltageunderseverecontingency.

A.injectorabsorbB.injectbutnotabsorbC.onlyabsorbD.neitherinjectnorabsorb

答案：A

解析：STATCOM基于电压源换流器，可四象限连续调节无功，既能注入也能吸收。

2.Ifthepowerfactorofa500kVtransmissionlinedropsto0.85lagging,thelinelosswillincreaseroughlyby______percentcomparedwithunitypowerfactorforthesamedeliveredactivepower.

A.38B.28C.18D.8

答案：A

解析：I=P/(U·cosφ)，当cosφ从1降到0.85，电流增大约17.6%，铜损与I2成正比，故损耗增约(1.1762–1)=38%。

3.Theterm“deadtank”inSF?circuit-breakernomenclatureindicatesthat______.

A.theinterruptingchamberisatearthpotential

B.thetankisfilledwithsoliddielectric

C.thebreakercannotauto-reclose

D.thecurrenttransformersaremountedonthebushing

答案：A

解析：dead-tank指灭弧室壳体接地，与live-tank对应。

4.WhichofthefollowingprotectionfunctionsismostlikelytobedisabledwhenthelinePTfusefails?

A.21B.87LC.67ND.50BF

答案：A

解析：21（距离保护）依赖电压量，PT断线将闭锁。

5.InIEC61850-9-2LE,thesamplingrateforprotectionapplicationsisfixedat______samplespercycle.

A.80B.256C.400D.4800

答案：B

解析：9-2LE规定每工频周期256点，即12.8kHz。

6.The“infinitegrid”assumptioninsynchronousmachinedynamicsimplies______.

A.constantvoltageandfrequencyatthepointofconnection

B.zeroshort-circuitratio

C.absenceofloadflowconstraints

D.purelyresistivesystemimpedance

答案：A

解析：无穷大电网电压频率恒定，内阻抗为零。

7.Whena100MWDFIG-basedwindfarmoperatesat0.9pfleading,thetotalreactivepowerexportedisapproximately______MVAr.

A.48B.52C.55D.60

答案：C

解析：Q=P·tan(arccos0.9)=100×0.484≈48MVAr，但DFIG自身无功能力约±0.33pu，再计及汇集线路充电功率，实际可达55MVAr。

8.Thecoronainceptionvoltageofasmooth630mm2ACSRconductorunderstandardatmosphericconditionsismost