···········································································································装订线··································································································山东建筑大学试卷共3页第1页2008至2009学年第2学期课程名称电力电子技术(专科)试卷A专业:建筑电气工程技术(专);考试性质:闭卷;考试时间120分钟题号一二三四总分分数得分阅卷人一.填空(1×10=10分)1.处于阻断状态的晶闸管,只有在阳极,且在门极加正向触发电压时,才能使其开通。2.电压型逆变器的输出电压波形为。3.有源逆变产生的条件之一是:变流电路输出侧有直流电源,其极性为___________,且满足|Ud||Ed|。4.单相全控桥式整流大电感负载电路中,晶闸管的导通角θ=___________。5.普通晶闸管的管芯是一种大功率___________层结构的半导体元件。6.三相半波可控整流中,晶闸管控制角的起始点在_________________。7.PWM控制技术就是的技术。8.单组单相全控桥能使电动机在Ⅰ、_________象限中工作。9.三相半波可控整流电路,在电阻性负载时,当控制角α≤30°,每个晶闸管的导通角θ=________。此电路的移相范围为_______。得分阅卷人二.单项选择(1×10=10分,选出一个正确答案,并将正确答案的号码填在题后面的括号内。)1.把交流电变成直流电的是()。A.逆变电路B.整流电路C.斩波电路D.调压电路2.升压斩波电路中,已知电源电压Ud=12V,导通比α=1/3,则负载电压U0=()。A.4VB.18VC.36VD.8V3.单相半波可控整流电路,带电阻负载,控制角α的最大移相范围为()。A.0°~90°B.0°~180°C.0°~120°D.0°~150°4.在GTR作为开关的电路中,若在转换的过程中出现从高电压小电流到低电压大电流的现象,则说明晶体管()。A.失控B.不能控制开通C.不能控制关断D.二次击穿5.对于同一晶闸管,维持电流IH与擎住电流IL的关系是()。A.IL≈(2~4)IHB.IH≈(2~4)ILC.IH=ILD.IH≥IL6.锯齿波为同步信号的触发电路中,若控制电压保持不变,同步信号的周期也不变,则改变同步电压的(),即能实现移相。A.幅值B.后沿C.斜率D.前沿7.以下器件不是全控型器件的是()。A.晶闸管B.电力晶体管C.电力场效应晶体管D.绝缘栅双极晶体管8.三相全控桥式整流电路在宽脉冲触发方式下,一个周期内所需要的触发脉冲共有六个,它们在相位上依次相差()。A.60°B.120°C.90°D.180°9.当晶闸管承受反向阳极电压时,不论门极加何种极性触发电压,管子都将工作在()。A.导通状态B.关断状态C.饱和状态D.不定10.大电感性负载的三相半波整流电路,流过晶闸管的平均电流为()。A.dI21B.dI22C.dI31D.dI33得分阅卷人三.简答题(5×7=35分)2.什么是PWM控制技术?班级姓名学号山东建筑大学试卷共3页第2页1.交交变频电路和交直交变频电路相比有何优缺点?2.什么是直流斩波电路?举出两种基本的斩波电路形式。3.画出三相半波可控整流电路,当α=90°时的输出电压ud及晶闸管两端承受电压uT1的波形。4.全控型器件的换流方式是哪一种?晶闸管可以有哪几种换流方式?5.晶闸管关断的条件是什么?6.什么是PWM控制?7.有源逆变和无源逆变有何区别?四.计算题(45分)1.(15分)单相半波可控整流电路对电阻性负载供电,已知U2=220V,要求输出直流平均电压Ud=80V,平均电流Id=50A,试计算晶闸管的控制角α,导通角θ各为何值,并计算流过晶闸管的电流平均值和有效值。得分阅卷人···········································································································装订线··································································································山东建筑大学试卷共3页第3页2.(15分)单相桥式半控整流电路,由220V经变压器供电,负载为大电感,并接有续流二极管,要求输出整流电压20~80V连续可调,最大负载电流为20A,最小控制角αmin=30°。试回答:(1)画出此时输出电压、电流波形;续流二极管的电流以及晶闸管承受电压的波形;(2)计算晶闸管电流有效值;(3)计算续流二极管的电流平均值。3.(15分)三相桥式全控整流电路,反电动势阻感负载,U2=100V,R=1Ω,L=∞,LB=2mH,求:当α=120°,E=-200V时Ud、Id和换相重叠角γ。···········································································································装订线·············································································································································································································装订线··································································································