Figure 3 shows the one-line diagram of a three-bus power system with generation at bus X. The magnitude of voltage at bus X is adjusted to 1.05 per unit. The scheduled loads at buses Y & Z are as on the diagram. Line impedances are marked in per unit on a 100 MVA base. i. Determine the bus voltages. Calculate branch current and power flow after 1

Figure 3 shows the one-line diagram of a three-bus power system with generation at bus X. The magnitude of voltage at bus X is adjusted to 1.05 per unit. The scheduled loads at buses Y & Z are as on the diagram. Line impedances are marked in per unit on a 100 MVA base. i. Determine the bus voltages. Calculate branch current and power flow after 1

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

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True or false 1. The size of Y bus matrix for 6 bus power system is (6)*(5). 2. PV buses constitute the maximum number in a power system. 3. A balanced three phase system consists of positive sequence currents only. 4. Sub transient reactance of generator have a greater value than synchronous reactance and transient reactance for generator 5. Newton Raphson method is high accurate among the other power flow methods.
Electrical Engineering Design a power system network consists of the following: į, 2 generators ii. 2 transformers iii. 2 transmission lines iv. Suitable number of busbars Then, for the designed network, perform the following: j. Load flow analysis. You must clearly identify the bus type to perform this. ii. Fault analysis – Balanced and unbalanced faults Next, perform manual calculations for the following: i, Load flow analysis using either Gauss Seidel or Newton Raphson Method. ii. Fault analysis (balanced and unbalanced faults) on any one fault point.
The fault current level of a circuit breaker used in a transmission line with phase voltage 2.2 kV and breaking capacity 60 MVA is ......................kA. Complete the answer.
Please neglect the simulation
The one-line diagram of a 6-bus power system is shown below with per unit impedances on common base. Determine the YBus.
Q6: A five-bus network has generators at buses 1 and 3 rated 270 and 225 MVA, respectively. The generator sub-transient reactances plus the reactances of the transformers connecting them to the buses are each 0.3 pu on the generator rating as base. The turns ratios of the transformers are such that the voltage base in each generator circuit is equal to the voltage rating of the generator. Line impedances in pu on a 100 MVA system base are shown in Fig. below. All resistances are neglected. Using the bus impedance matrix for the network which includes the generator and transformer reactances, find the sub-transient current in a three phase fault at bus 4 and the current coming to the faulted bus over each line. Prefault current is to be neglected and all voltages are assumed to be 1 pu before the fault occurs. 3 j0.126 1.0/0 j0.1333 ll 1.0/0 j0.168 ll ell j0.210 ll j0.252 4 j0.336 ll j0.1111 lill j0.126 all ll
Figure below shows the single-line diagram of three-bus power system with generation at bus 1 and bus 3. The voltage at bus 1 is V₁ = 1.025/0° per unit. The voltage magnitude at bus 3 is fixed at 1.05 per unit with a real power generation of 250 MW. The scheduled load on bus 2 is marked on the diagram. Line impedances are marked in per unit on a 100 MVA base. Line resistances and line charging susceptances are neglected. By using Gauss-Seidel method and initial estimates of V₂(0) = 1.020° and V3(0) = 1.0520°, determine V₂ and V3. Perform calculation for one iteration. V₁ = 1.025/0° j0.1 Slack Bus j0.2 j0.4 j0.2 3 j0.1 250 MW 150 Mvar |V3|=1.05 P3 = 250 MW
The positive sequence reactance for the power system shown in Figure below are in per unit on a common MVA base. Resistances are neglected and the negative sequence impedances are assumed to be the same as the positive sequence impedances. A bolted line to line fault occurs between phase 'b' and phase 'c' at bus 2. Before the fault occurrence, all bus voltages are 1.0 per unit. (i) Obtain the positive sequence bus impedance matrix. (ii) Find the fault current, the three phase bus voltages during fault at all the buses. (iii) Find the three phase currents through the transformer T1 during the fault. 2 3 XL1 X= j0.05 (G1 X= j0.05 G2 XT1 XT2 XL2 4 XT1 XL1 X12 XT2 jo.15 jo.25 jo.5 jo.15
A single-line diagram of a four-bus system is shown in Figure 3: BUS 3 b- Assume that: 0.25 /0,25 ww m 10.1 j0.2 Zbus- j* Let a three-phase fault occur at bus 2 of the network. a- Determine Ybus of this system. BUS 2 0.125 BUS 1 10.2 j0,4 (ground is the reference node) Figure 3: Four-bus system. BUS 4 www m 10.1 0.2437 0.1939 0.1545 0.1457 0.1939 0.2295 0.1495 0.1507 0.1545 0.1495 0.1956 0.1046 0.1457 0.1507 0.1046 0.1955 10.2 c- Using Zbus, calculate the initial symmetrical RMS current in the fault, Assume the prefault voltage Vf at bus 2 to be 10°, and neglect all prefault currents. d- Determine the voltages during the fault at buses 1, 3, and 4. e- Compute the fault currents contributed to bus 2 by the adjacent unfaulted buses 1, 3, and 4. f Find the current flow in the line from bus 3 to bus 1.
The bus impedance matrix for a three-bus power system has per-unit elements as: Z11 = 0.5 Z12 = 0.4 Z13 = 0.8 Z21 = 1 Z22 = 0.5 Z23 = 0.6 Z31 = 0.5 Z32 = 1.2 Z33 = 1 Prefault voltage is 1 per unit and prefault current is neglected. A three-phase short circuit occurs at bus 3. Determine the subtransient fault current. Round your answer to 2 decimal places.
Refer to the 5-bus data given below. Sbase = 400 MVA, the base voltage is 15.0 kV for buses 1 and 3, and 345 kV for buses 2, 4, 5. Note that 1-5 and 3-4 are 15/345 kV transformers.a) Draw a one-line diagram of the power system.b) Find the elements Y23, Y43, Y11 Y33 of the system bus admittance matrix.
I. Further simplify this diagram to a Thevenin model with (Vf) as the generator. 2. Determine the per unit current flowing and the actual current that flows through the fault switch when closed (assume Ibase is 251 A). 3. Describe the operational features of power relay and circuit breaker designed to protect a radial power feeder, include in your description forms of protection provided by the relay and methods of obtaining line data