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Instructor: Ayman El-HagOffice No. EB1-237

Phone No. 515-2965

E-mail: aelhag@aus.edu

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Course References

H. Saadat, Power System Analysis, 3rdedition. PSA Publishing LLC, 2010.

J. D. Glover, M. S. Sarma and T. Overbye,Power System Analysis and Design, 5thedition. PWS Publishing Company, 2011..

Course notes (iLearn)

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Marking Scheme

Quizzes and homework 15%

Course Project 15%

Two Midterms 40%

Final 30%

Total 100%

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Home work: 4-5 assignments

1-2 weeks will be given for each homework

No late homework will be accepted.

Quizzes 4-5 quizzes will be given.

The topic of the quiz will be from the homework.

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Project: Deadline of the project is: 19.05.2014

Midterms:

Exam 1: 26.03.2014, during class time.

Exam 2: 14.05.2014, during class time

Final

The final will be on Monday, May 26 at 8:0010:00

a.m..

For more details, kindly refer to the course syllabus

posted in iLearn.10:52 AM 6

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Course Outline

Model and analyze equivalent circuitrepresentation of different components of a

power system:

Synchronous generators Transformers

Transmission lines (short, medium and long)

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Course Outline

Analyze the steady-state operation of a powersystem.

Load flow analysis

Analyze the transient operation of the power

system.

Short circuit analysis

Transient stability

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Power System Basics

All power systems have three major components:Generation, Load and Transmission.

Generation: Creates electric power.

Load: Consumes electric power.

Transmission: Transmits electric power from

generation to load.

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Power system

Generation TransmissionLoads

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Power system

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Generation (in Dubai)

ELECTRICITY 2005 2006

** Installed Capacity MW 3,833 4,599*

Gas Turbines MW 2,660 3,026

Steam Turbines MW 1,173 1,173

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GAS TURBINE COMBINED CYCLE

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STEAM TURBINE

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Transmission

Goal is to move electric power from generation toload with as low of losses and cost as possible.

P V I or P/V I

Losses are 3*I2 R (for three phase)

Less losses at higher voltages, but more costly to

construct and insulate.

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Transmission

500 kV transmission line 132 kV transmission line

69 kV transmission line

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Transmission and Distribution

Typical high voltage transmission voltages are 500,345, 230, 161, 138 and 69 kV.

Transmission tends to be a grid system, so each bus

is supplied from two or more directions. Lower voltage lines are used for distribution, with a

typical voltages of 13.8, 11 and 6.6 kV.

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Transmission and distribution Lines (Dubai)

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Loads

Can range in size from less than a single watt to 10sof MW.

Loads are usually aggregated.

The aggregate load changes with time, with strongdaily, weekly and seasonal cycles.

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Loads (Dubai)

System Peak Demand (MW) 2005 ____ 2006 ____

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System Peak Demand (MW) 2011 ____ 2012 ____

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Loads (Dubai)

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Basics of Power SystemAnalysis

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Single-line Diagram

Most power systems are balanced three phasesystems.

A balanced three phase system can be modeled as a

single (or one) line. Single-lines show the major power system

components, such as generators, loads, transmission

lines.

Components join together at a bus.10:52 AM

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Example: Single-Line Diagram

Bus 2 Bus 1

Bus 3

200 MW

100 MVR

150 MWMW

150 MWMW

35 MVRMVR

114 MVRMVR

100 MW50 MVR

1.00 pu

-17 MW

3 MVR

17 MW

-3 MVR

-33 MW

10 MVR

33 MW

-10 MVR

17 MW

-5 MVR

-17 MW

5 MVR

1.00 pu

1.00 pu

100 MW

2 MVR

100 MWAGC ON

AVR ON

AGC ON

AVR ON

Generator

LoadBus

Circuit Breaker

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Power Balance Constraints

Power flow refers to how the power is movingthrough the system.

At all times the total power flowing into any bus

MUST be zero! This is know as Kirchhoffs law. And it can not be

repealed or modified.

Power is lost in the transmission system.

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Basic Power Control

Opening a circuit breaker causes the power flow toinstantaneously(nearly) change.

No other way to directly control power flow in a

transmission line. By changing generation we can indirectly change

this flow.

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Transmission Line Limits

Power flow in transmission line is limited by anumber of considerations.

Losses (I2 R) can heat up the line, causing it to sag.

This gives line an upper thermal limit. Thermal limits depend upon ambient conditions.

Many utilities use winter/summer limits.

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Overloaded Transmission Line

Bus 2 Bus 1

Bus 3

359 MW

179 MVR

150 MWMW

150 MWMW

102 MVRMVR

234 MVRMVR

179 MW90 MVR

1.00 pu

-152 MW

37 MVR

154 MW

-24 MVR

-57 MW

18 MVR

58 MW

-16 MVR

-87 MW

29 MVR

89 MW

-24 MVR

1.00 pu

1.00 pu

343 MW

-49 MVR

104% 104%

100 MWAGC ON

AVR ON

AGC ON

AVR ON

Thermal limit

of 150 MVA

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Reactive Power

Reactive power is supplied by: generators

capacitors

transmission lines loads

Reactive power is consumed by

loads

transmission lines and transformers

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Voltage Magnitude

Power systems must supply electric power within anarrow voltage range, typically with 5% of a

nominal value.

For example, wall outlet should supply120 volts, with an acceptable range from 114 to 126

volts.

Voltage regulation is a vital part of systemoperations.

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Voltage Regulation

A number of different types of devices participate insystem voltage regulation

generators: reactive power output is automatically

changed to keep terminal voltage within range. capacitors: switched either manually or automatically to

keep the voltage within a range.

Load-tap-changing (LTC) transformers: vary their off-nominal tap ratio to keep a voltage within a specified

range.

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History of power system (war of current)

Nikola Tesla and Thomas Edisonbecame enemies

due to Edison's promotion of direct current (DC) for

electric powerdistribution over the alternating

current (AC) advocated by Tesla. Which system you think is better and why?

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