Question

Q1) Two ideal voltage sources designated as machines 1 and 2 are connected as shown in Figure 1. If E! = 100.200 V, E-100し300 V and Z = 0 +JS a) Determine whether each machine is generating or consuming real power and the amount b) Determine whether each machine is receiving or supplying reactive power and the amount c) Determine the P and Q absorbed by the impedance 2 #2 Figure 1: Ideal voltage sources connected through impedance Z Q2) In a balanced three-phase circuit the voltage Vab is 173.20 V. Determine all the voltages and the currents in a Y-connected load having Z1-10220° Assume that the phase sequence is abc 3) The terminal voltage of a Y-connected load consisting of three equal impedances of 20L30° Ω is 4.4 kV line to line. The impedance of cach of the three lines connecting the load to a bus at a substation is Z1 = 1.4L75。쇼 Find the line-to-line voltage at the substation bus. 04) Find the solution of Question 3 by working in per unit on a base of 4.4 kV.127 A so that both voltage and current magnitudes will be 1.0 per unit. Current rather than kilovoltamperes is specified here since the latter quantity does not enter the problem Q5) The reactance of a generator designated X is given as 0.25 per unit based on the generator's nameplate rating of 18 kV, 500 AIVA The base for calculations is 20 kV, 100 MVA. Find X" on the new base. Q6) If N.-2000 and N2-500 in the circuit of Figure 2 and if v, = 1200し00 V and 11 = 51- 30° A with impedance Z2 connacted across winding 2 find V. 12. Ζ2 and the impedance Z, which is defined as the value of Zo referred to the primary side of the transformer

Answer 1