Chapter 1: The Power System-An Overiew

Question 1

What is the major problem we face in power system analysis?

Answer 1

Not having a real system with which to simulate in the laboratory.

Question 2

How have computers helped?

Answer 2

Computers have brought about computer-simulated power systems.

Question 3

What makes MATLAB suitable for power system analysis?

Answer 3

Because it is a matrix-based software.

Question 4

What is the power system toolbox for?

Answer 4

It allows students to analyze and design power systems without having to do detailed programming.

Question 5

Why is electrical energy the most popular form of energy?

Answer 5

Because it can be transported easily with high efficiency and low cost.

Question 6

Where was the first electric network developed in the US, and who developed it?

Answer 6

1882, Pearl Street Station in NYC Manhattan by Thomas Edison.

Question 7

What type of power did the station supply?

Answer 7

DC Power.

Question 8

Who invented a transformer, and what is its purpose?

Answer 8

William Stanley. It raises or lowers AC voltage for transmission and distribution.

Question 9

Who invented an induction motor?

Answer 9

Nikola Tesla.

Question 10

What is the advantage of AC over DC in bulk power generation and distribution?

Answer 10

1. Due to the lack of commutators, more power can be produced conveniently at higher voltages.
2. Energy can be delivered over longer distances with lower power loss.

Question 11

What is the standard AC frequency in the US?

Answer 11

60Hz.

Question 12

What is the standard AC frequency in Nigeria?

Answer 12

50Hz.

Question 13

What is the standard AC frequency in Canada?

Answer 13

60Hz.

Question 14

What is the standard AC frequency in Europe?

Answer 14

50Hz.

Question 15

Why is the transmission of EHV voltage in DC more economical than AC?

Answer 15

DC lines have no reactance and are capable of transferring more power for the same conductor size than AC lines.

Question 16

What is the main disadvantage of a DC link?

Answer 16

Production of harmonics, requiring filtering and reactive power compensation.

Question 17

What is a power grid?

Answer 17

An interconnection of power elements for the bulk generation, distribution, and transmission of power.

Question 18

What are the benefits of an interconnected system?

Answer 18

It makes energy generation and transmission more reliable and economical.

Question 19

What is open transmission access?

Answer 19

A policy that allows multiple entities to use the transmission network competitively.

Question 20

What is meant by reliability in the power industry?

Answer 20

Steady and uninterrupted power supply to all electricity consumers.

Question 21

What is the most essential component of AC generation?

Answer 21

The three-phase AC generator, known as a synchronous generator/alternator.

Question 22

How does the synchronous generator work? How is its excitation different from a DC generator?

Answer 22

A synchronous generator works by rotating a magnetic field within a stationary armature to generate electricity.
It differs from a DC generator in that it uses an external excitation system, while a DC generator is usually self-excited.

Question 23

What are brushless DC excitation systems?

Answer 23

Systems that provide field excitation to a synchronous generator without using slip rings.

Question 24

What is a prime mover?

Answer 24

The source of mechanical power that drives a generator (e.g., steam turbine, gas turbine, water turbine).

Question 25

What is a bus?

Answer 25

A point of interconnection of generators, loads, and other power elements in a power system.

Question 26

What is a transformer?

Answer 26

An electromechanical device that transfers power at very high efficiency from one voltage level to another.

Question 27

What does ANSI stand for?

Answer 27

American National Standards Institute.

Question 28

What is a switching station used for?

Answer 28

Switching circuits in and out of service.

Question 29

What is a primary substation?

Answer 29

A substation where high-voltage transmission lines are terminated.

Question 30

What is the transmission network?

Answer 30

The system that connects high-voltage substations through step-down transformers to distribution substations.

Question 31

Why are capacitor banks and reactor banks usually installed at substations?

Answer 31

For maintaining transmission line voltage.

Question 32

What is the distribution system used for?

Answer 32

It connects distribution substations to the consumers' service entrance equipment.

Question 33

What are the major classifications of power distribution systems?

Answer 33

Overhead and underground; Radial, ring, and interconnected.

Question 34

What are the major divisions of loads in power systems?

Answer 34

Industrial, commercial, and residential.

Question 35

What are composite loads as it relates to industrial consumers?

Answer 35

Induction motors form a high proportion of these loads. They are essentially a function of voltage and frequency.

Question 36

What is the major difference between industrial and commercial/residential loads?

Answer 36

Industrial loads are a function of voltage and frequency and consume large amounts of reactive power, while commercial and residential loads do not.

Question 37

What is peak or maximum demand?

Answer 37

The greatest value of load in a 24-hour period.

Question 38

What is the load factor?

Answer 38

It is used to evaluate the usefulness of a generating plant. It is the ratio of the average load to the peak load over a designated period.

Question 39

Must the load factor be higher or lower for a generating company to operate economically?

Answer 39

Higher.

Question 40

What is the utilization factor?

Answer 40

The ratio of the maximum demand to installed capacity.

Question 41

What is the plant factor?

Answer 41

It is the ratio of annual energy generation to the plant capacity multiplied by 8760.

Question 42

Which MATLAB Hadi Saadat function is used to obtain the plot of the load cycle for a given interval?

Answer 42

Not specified in the provided information.

Question 43

What are switchgears?

Answer 43

Devices used to control, protect, and isolate electrical equipment.

Question 44

In what order do design, modeling, and analysis come?

Answer 44

Modeling, Analysis, Design.

Question 45

What are the major components of a power system?

Answer 45

Generation, Transmission, Distribution, System Protection, System Monitoring Centers.