1、第 1 页 共 2 页 华北电力大学华北电力大学 _ _06-0706-07_ _学年第学年第_ _1 1_ _学期考试试卷学期考试试卷(A)(A) 课程名称电力系统分析基础（双语）课程编号00200290考核日期时间 2007.1.4 9：0011:00 专业班级电气0401/2/3需要份数120送交日期2006-12-15 考试方式闭卷试卷页数2AB卷齐全是 命题教师艾欣 刘诗圣主任签字备注 班级:姓名:学号: 1.(20%)For a voltage source, its phasor representation is V = 120 -45oand its frequency is
2、 60 Hz, (a)What is the instantaneous voltageV(t)? (b)Draw the phasor diagram of V = 120 -45o! (c)Plot the instantaneous voltage waveform forV(t). Make sure you label your graph properly! (d)This voltage source is connected to a RL load with R = 10 ohms and L = 20 mH, what is the instantaneous curren
3、ti(t)? (e)What is the power factor in part (d)? 2.(20%)A 200kVAsingle phase transformer, 4,160 V/480V,60 Hz, has the following test results: OpenOpenOpenOpen circuitcircuitcircuitcircuit testtesttesttest: V=480 V is applied to the 480 V winding and 4,160 winding is opened, I = 10 A, P = 1000 W; Shor
4、tShortShortShort circuitcircuitcircuitcircuit testtesttesttest: V = 208 V is applied to the 4,160 V winding, I = 48 A, P = 900 W; Find the equivalent circuit in ohms from the high voltage side. 3.(20%)A 3-phase load has the following rated information: 250 kVA, 0.8 power factor leading at 480V,Y-con
5、nected. Do the following: (a)Find per phase impedance in ohms (b) Find per phase impedance in per unit using 250kVAand 480 V as base value for 3-phase power and line to line voltage 4.(20%)A fully transposed transmission line was constructed using ACSR conductor called “drake.”Bundle conductors are
6、used and there are two conductors per phase and the distance between them is 0.4 meter.The three phase bundle conductors are placed horizontally with distance between the center of each phase conductor is 12 m. (a)Find the per unit length R, L, and C for this transmission line (b)Find the characteristic impedanceZc (c)If the length of this line is 180 km, what would be the most suitable per phase equivalent circuit for this transmission line? 第 2 页 共 2 页 5.（30）已知两节点电力系统及其参数（标幺值）如图所示，计算系统潮流，求： （1）系统的节点导纳阵； （2）直角坐标形式的功率方程； （3）雅可比矩阵和修正方程式； （4）采用牛顿拉夫逊法第1次迭代求解的结果。
