Power System Analysis Problem Sets

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the purpose of the per-unit impedance diagram in Figure 27?

To calculate the real power consumed by a load

To simplify the analysis of power systems by reducing the number of variables (correct)

To visualize the single-line diagram of a power system

To determine the nominal voltage of a power system

What is the significance of the '¾»' symbol in the one-line diagram of Figure 28?

It represents a step-down transformer

It represents a load

It represents a step-up transformer (correct)

It represents a transmission line

In the per-unit system, what is the advantage of using a base value for voltage and current?

It simplifies the analysis of power systems by eliminating the need for complex calculations

It allows for the calculation of real power

It provides a normalized representation of the power system, enabling easier comparison of different components (correct)

It is necessary for the calculation of reactive power

What is the purpose of G1 and G2 in the per-unit impedance diagram of Figure 27?

They represent the generators in the power system Signup and view all the answers

What is the significance of the 'µ´' symbol in the per-unit impedance diagram of Figure 27?

It represents the per-unit value of a component Signup and view all the answers

What is the purpose of the one-line diagram in Figure 28?

To visualize the complexity of a power system Signup and view all the answers

What is the value of S2 in pu?

1.848 + j0.066 Signup and view all the answers

What is the value of V3 in pu?

1.06 0° Signup and view all the answers

What is the value of I3 in pu?

-j0.2 Signup and view all the answers

What is the line-to-line voltage at bus 2?

126.5 kV Signup and view all the answers

What is the value of I2 in pu?

1.68 - j0.06 Signup and view all the answers

What is the line-to-line voltage at bus 1?

27.6 kV Signup and view all the answers

What is the per-unit value of S2 in the given problem?

0.1848 + j0.0066 Signup and view all the answers

What is the value of V3 in per-unit?

1.06 0° Signup and view all the answers

What is the line-to-line voltage at bus 2 in kV?

440 kV Signup and view all the answers

What is the value of I2 in per-unit?

0.054 + j0.332 Signup and view all the answers

What is the transformer reactance in percent?

20% Signup and view all the answers

What is the value of S3 in per-unit?

0 MW + j0.20 Signup and view all the answers

What is the line impedance in ohms?

j66.125 Signup and view all the answers

What is the line-to-line voltage at bus 1 in kV?

480 kV Signup and view all the answers

Study Notes

Problem 3.11

The per unit impedance diagram for Problem 3.11 is shown in Figure 27.
It consists of two lines: Line 1 with a voltage of 220 kV and Line 2 with a voltage of 110 kV.

Problem 3.14

The one-line diagram for Problem 3.14 is shown in Figure 28.
The three-phase power and line-line ratings are given as:
- S2 = 15.93 MW - j33.4 Mvar = 0.1593 - j0.334 pu
- S3 = 77.00 MW + j14.0 Mvar = 0.7700 + j0.140 pu
The line-to-line voltages at buses 2 and 1 are calculated as:
- V2 = 440 kV
- V1 = 480 kV

Problem 3.17

The one-line diagram for Problem 3.17 is shown in Figure 33.
The transformer reactance is 20% on a base of 100-MVA, 23/115-kV.
The line impedance is Z = j66.125Ω.
The load at bus 2 is S2 = 184.8 MW + j6.6 Mvar and at bus 3 is S3 = 0 MW + j20 Mvar.
The voltage at bus 3 is held at 1156 0◦ kV.
The voltages at buses 2 and 1 are calculated as:
- V2 = 126.5 kV
- V1 = 27.6 kV

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Solve problem sets related to power system analysis, including impedance diagrams and one-line diagrams. Calculate power and line-line ratings, and determine line-to-line voltages at buses.