9.1 The single-line diagram of a three-phase power system is shown in Figure 9.17. Equipment ratings are given as follows: Synchronous generators: GI 1000 MVA 15 kV G2 1000 MVA 15 kV G3 500 MVA 13.8 kV 13.8 kV G4 750 MVA Transformers: TI 1000 MVA T2 1000 MVA T3 500 MVA T4 750 MVA Transmission lines: 1-2 765 kV 1-3 765 kV 2-3 765 kV XX₂ = 0.18, X, -0.07 per unit X=X₂-0.20, X, 0.10 per unit XX₂ = 0.15, X, = 0.05 per unit X-0.30, X₂= 0.40, X, 0.10 per unit 15 kV A/765 kV Y 15 kV A/765 kV Y 15kV Y/765kVY 15 kV Y/765 kVY X = 0.10 per unit X = 0.10 per unit X = 0.12 per unit X= 0.11 per unit Χ = 50 Ω, X = 150 Ω X = 40 Ω, X = 100 Ω X = 100 Ω Χ, " 40 Ω, Line 1-3 Line 1-2 T₂ Line 2-3 The inductor connected to Generator 3 neutral has a reactance of 0.05 per unit using generator 3 ratings as a base. Find fault current occurs at bus 3 if: 1- L-G fault actual 2- L-L-G fault 3- L-L fault base. using a 1000-MVA, 765-kV base in the zone of line 1-2 25 ase والمسيرا FI Pr
Load flow analysis
Load flow analysis is a study or numerical calculation of the power flow of power in steady-state conditions in any electrical system. It is used to determine the flow of power (real and reactive), voltage, or current in a system under any load conditions.
Nodal Matrix
The nodal matrix or simply known as admittance matrix, generally in engineering term it is called Y Matrix or Y bus, since it involve matrices so it is also referred as a n into n order matrix that represents a power system with n number of buses. It shows the buses' nodal admittance in a power system. The Y matrix is rather sparse in actual systems with thousands of buses. In the power system the transmission cables connect each bus to only a few other buses. Also the important data that one needs for have a power flow study is the Y Matrix.
Types of Buses
A bus is a type of system of communication that transfers data between the components inside a computer or between two or more computers. With multiple hardware connections, the earlier buses were parallel electrical wires but the term "bus" is now used for any type of physical arrangement which provides the same type of logical functions similar to the parallel electrical bus. Both parallel and bit connections are used by modern buses. They can be wired either electrical parallel or daisy chain topology or are connected by hubs which are switched same as in the case of Universal Serial Bus or USB.
![9.1
The single-line diagram of a three-phase power system is shown in
Figure 9.17. Equipment ratings are given as follows:
Synchronous generators:
GI 1000 MVA 15 kV
G2 1000 MVA 15 kV
G3 500 MVA
G4 750 MVA
13.8 kV
13.8 kV
Transformers:
TI 1000 MVA
T2 1000 MVA
T3 500 MVA
T4 750 MVA
Transmission lines:
1-2 765 kV
1-3 765 kV
2-3 765 kV
X = X₂ = 0.18, X, = 0.07 per unit
X=X₂-0.20, X, 0.10 per unit
X = X₂ = 0.15, X, = 0.05 per unit
X=0.30, X₂ = 0.40, Xo = 0.10 per unit
15 kV A/765 kVY
15 kV A/765 kVY
15kV Y/765kV Y
15 kV Y/765 kVY
Χ
= 50 Ω,
X
= 40 Ω,
Χ = 40 Ω,
X =
X-0.10 per unit
X = 0.10 per unit
X = 0.12 per unit
X = 0.11 per unit
150 Ω
Χο = 100 Ω
X = 100 Ω
Line 1-2
Line 1-3
=
2
Line 2-3
3
The inductor
connected to
Generator 3 neutral
has a reactance of
0.05 per unit using
generator 3 ratings
as a base. Find
fault current
occurs at bus 3 if:
1- L-G fault actual
2- L-L-G fault 3-
L-L fault base.
using a 1000-MVA,
765-kV base in the
zone of line 1-2
T₂
ase
FIGURE 9.17
Problem 9.1](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2Ff82bbcf2-7a0e-46b9-b115-f6feeae78cf6%2F9d56b8aa-0d60-4d5e-b1f8-f4c248a97678%2F8shxyi2_processed.jpeg&w=3840&q=75)
![](/static/compass_v2/shared-icons/check-mark.png)
Step by step
Solved in 6 steps with 6 images
![Blurred answer](/static/compass_v2/solution-images/blurred-answer.jpg)
![Power System Analysis and Design (MindTap Course …](https://www.bartleby.com/isbn_cover_images/9781305632134/9781305632134_smallCoverImage.gif)
![Power System Analysis and Design (MindTap Course …](https://www.bartleby.com/isbn_cover_images/9781305632134/9781305632134_smallCoverImage.gif)