Power system OBLEM (4)- (14 marks) I). a) The three phase currents in a 3 phase...
8.25 A three-phase balanced \(Y\) -connected load with series impedances of \((8+j 24) \Omega\) per phase and mutual impedance between any two phases of \(j 4 \Omega\) is supplied by a three-phase unbalanced source with line-to-neutral voltages of \(V_{a n}=200 \angle 25^{\circ}, V_{b n}=100 \angle-155^{\circ}\), \(V_{c n}=80 \angle 100^{\circ} \mathrm{V}\). The load and source neutrals are both solidly grounded. Determine: (a) the load sequence impedance matrix, (b) the symmetrical components of the line-toneutral voltages, (c) the symmetrical components of the...
Q3 (3 marks) (4 marks) Two wattmeters are connected in the a and b phases, with the ends of the voltage coils connected in the c phase, of a balanced three phase star- connected lagging load. Draw a circuit diagram showing the three phases, the wattmeters and the load. Draw a phasor diagram of the phase voltages and currents, the voltages across the wattmeter voltage coils, and the angles between the wattmeter voltages and currents. Show that the sum of...
QUESTION 5 In a Y-connected, 3-phase, 4-wire p.p.s load, a current of 45.9L -36 A is flowing in the neutral. The positive and negative symmetrical components of the current in line b are: 1b2 = 18.6 L-15 A 1b1 = 21.3 L 64 A The voltage drops across the phases of the load are: Vc = 184 L 52 V Vo=226 L 60 V Va= 204 L-85 V 5.1 Calculate the impedances of the load [14] 5.2 Calculate the total...
I. A balanced three-phase positive sequence wye-connected 60Hz source voltage has line-neutral voltage of V, 1000 V. It is connected to a three- phase wye connected load whose impedance is z 50+j37.7 2 a. Find line currents ia ib, ic and line-line voltages Vab, Vbo Vac b. Find the total complex power delivered to the load. c. Find delta-connected capacitor bank needed to bring the PF to 0.95 (lagging) of system. d. Re-calculate currents la, ib, io with Case c....
I. A balanced three-phase positive sequence wye-connected 60Hz source voltage has line-neutral voltage of V, 1000 V. It is connected to a three- phase wye connected load whose impedance is z 50+j37.7 2 a. Find line currents ia ib, ic and line-line voltages Vab, Vbo Vac b. Find the total complex power delivered to the load. c. Find delta-connected capacitor bank needed to bring the PF to 0.95 (lagging) of system. d. Re-calculate currents la, ib, io with Case c....
A 3-phase 4 wire symmetrical (balanced) Y-connected source with
line voltage 340V (take the phase of VanVan to be 0 degrees) feeds
an unbalanced three phase load formed by the impedances
ZY1=14+j(14)Ω, ZY2=7+j(11)Ω and ZY3=20+j(−14)Ω connected in a Y
(a.k.a. “star”, or a “tee”) configuration. Find the line currents,
neutral current (current in the fourth “return” wire), and active
power in each phase.
(20 points) A 3-phase 4 wire symmetrical (balanced) Yconnected source with line voltage 340V (take the phase...
Learning Goal: To find voltages and power in a balanced three-phase circuit. Three identical AC voltage sources, each with amplitude 170 V, are connected in a Y configuration to three identical resistances, each 50 , also in a Y configuration. There is also a fourth, neutral line in the circuit (see diagram). The voltage sources are each 120° out of phase from the other two sources R RE R - Part A - Load current What is the RMS current...
Question 2: Three phase circuit. (100p) A wye connected generator supplies a delta connected balanced load through short feeder. seree the load line to neutral voltage as reference voltage phase angle zero. 02.1 Q2.2 Q2.3 Q2.4 Draw the equivalent circuit. 10p Calculate the load line-to-neutral voltages and line-to-line voltages. 20p Calculate the delta load currents and feeder currents. 20p Calculate the supply wye connected generator line-to-neutral voltages. Is the obtained values are acceptable? Calculate the generator real and reactive power...
Question 4 (15 marks) Figure 4 shows a single-phase diode bridge rectifier supplied from the 230 V, 50 Hz mains via a step- down transformer D2 D SW + n: 1 + 230 V 33mF 20 0 Vo 50 Hz D3 D4 Figure 4 (a) Assuming that the switch SW is open, explain the operation of the rectifier in figure 4 with the aid of the waveforms of the input and output voltages (v, and v) [4 marks (b) With...
A three-phase unbalanced source with the following phase to neutral voltages: 300-120 20090 10ol-30 1001-30 is applied to the circuit of balanced star. The star common point is connected to the impedance of Z, -2j The load series impedance per phase is Z, -10+40j a) The load sequence impednace matrix Zo b) The symmetrical components of voltage. (magnitude and angle) ground through Determine
A three-phase unbalanced source with the following phase to neutral voltages: 300-120 20090 10ol-30 1001-30 is applied...