1、华北电力大学 _06-07_学年第_1_学期考试试卷(B)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2007.1.49：0011:00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2A B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.(10%)For a voltage source, its phasor representation is V = 120 -45o and its frequency is 60 Hz, (a)What is the instantaneous voltage V(
2、t)?(b)Draw the phasor diagram of V = 120 -45o!(c)Plot the instantaneous voltage waveform for V(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 current i(t)?(e)What is the power factor in part (d)?
3、2.(20%)A 200 kVA single phase transformer, 4,160 V/480 V, 60 Hz, has the following test results:Open circuit test:V=480 V is applied to the 480 V winding and 4,160 winding is opened, I = 10 A, P = 1000 W;Short circuit test:V = 208 V is applied to the 4,160 V winding, I = 48 A, P = 900 W;Find the equ
4、ivalent 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 480 V, Y-connected. Do the following:(a)Find per phase impedance in ohms(b)Find per phase impedance in per unit using 250 kVA and 480 V as base value for
5、 3-phase power and line to line voltage4.(20%)A 1000-MVA, 60 Hz turbine-generator has a regulation constant R = 0.05 per unit based on its own power rating. Assume a fixed reference power setting, steady state frequency is at 60.05 Hz and output power of the turbine generator is 750 MW. Then something happens and the output frequency goes down to 59.9 Hz after a new steady state is reached. What would be the new output power of this turbine generator in MW?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。第 2 页 共 2 页
