BEF 25503 Power Systems Chapter 1 - author.uthm.edu.myauthor.uthm.edu.my/uthm/www/content/lessons/2779/Chapter 1.pdf · • PSS/E and PSS/Adept (Siemens)PSS/E and PSS/Adept (Siemens)

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BEF 25503Power SystemsPower Systems

BEF 25503

OVERVIEW OF POWER SYSTEMS

Chapter 1

Knowing Your Lecturer…Engr. Dr. Kok Boon Ching

Room : Block A4, 1st Floor (CAD)Tel : 07-4537313/ 012-6107918Email : [email protected]

Research interests:Research interests: 1) Renewable energy2) Energy Harvesting System3) Energy Savings4) Electrical System Design

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Outlines

Introduction11

History of Electric Power Systems

Modern Electric Power System

55

44

33

22

The Sources of Electrical Energy

Basic Computer Analysis for Power System

Power Systems in Malaysia66

55

What is Electric Power System?

Electric power system is a composite system of

Introduction

Electric power system is a composite system of generation, transmission, and distribution systems.

Generation Stations

Transmission Lines

Distribution Systems

Step-up Transformers

Step-down Transformers Consumers

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IntroductionStep-up Voltage

110 kV – 1000 kV

Generation

TransmissionDistribution

Step-down Voltage132 kV – 66 kVGeneration Voltage

13 kV – 25 kV

Loads

Distribution Voltage11 kV – 33 kV

Generator is mostly a synchronous type.Transmission system can be either HVAC and/or HVDC.Distribution involves several substations.Loads consume P and Q.

• Generators

Introduction

Generators 3-phase ac synchronous generator or alternator.

Have 2 rotating fields – rotor (synchronous speed and excited by dc current) & stator windings (3-phase armature current).

Size of generators – 50 MW to 1500 MW.

Mechanical power – prime mover (hydraulic turbines, steam turbines, gas turbines).

Steam/ Gas turbines – high speeds, 1800/ 3600 rpm.

Hydraulic turbines – low speed, 150 – 300 rpm.

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• Transformers Step-up transformers are used to increase the voltage level for

long distances power transmission.

The power transferred to the secondary is almost the same as

Introduction

The power transferred to the secondary is almost the same as the primary.

In modern utility system, the power may undergo 4 or 5 transformations between generator and ultimate user.

Transfer electric energy from generating units at various

Introduction

locations to the distribution system. Transfer of power between regions during emergencies. In Malaysia, transmission voltage are standardized at 66

kV, 132 kV, 275 kV, and 500 kV line-to-line. Subtransmission connects the HV substation through

step-down transformers to the distribution substation. Typical subtransmission voltage level ranges from 66 kV

to 132 kV. Capacitor banks/ reactor banks are used to maintain the

transmission line voltage.

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The primary distribution lines are ranging from 6 6 kV to

Introduction

The primary distribution lines are ranging from 6.6 kV to 33 kV.

The secondary distribution lines are normally at 415 V and 240 V.

Distribution systems are both overhead and underground.

Divided into industrial commercial and residential

Introduction

Divided into industrial, commercial, and residential.

Very large industrial loads may be served from the transmission system.

Industrial loads – mostly induction motors.

Commercial & residential loads – lighting, heating, and cooling.

Greatest value of load during a 24-hr period is called peak or maximum demand.

Daily Load factor = average load X 24 hr/ peak load X 24 hr.

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How is Electricity Measured?

Electricity is measured in units of power called WATTS

Introduction

WATTS.

1 W = 1 J/s

1 hp = 745.7 W – use in machine rating.

A kilowatt represents 1,000 watts.

A kilowatt-hour (kWh) is equal to the energy of 1,000 watts working for one hour.

For example, if you use a 125W of LED TV for 8 hours a day, you have used 1000 W of power, or 1.0 kWh of electrical energy.

How is Electricity Measured?

1 kWh = 1 kW x 1 hr = 1000 W x 3600 sec

1 kWh 36 105 W tt J l

Introduction

1 kWh = 36 x 105 Watt-sec or Joules

1 calorie = 1 gm of water x 1C = 4.18 Joules

1 B.Th.U (British Thermal Unit) = 1 lb x 1F

1 B.Th.U = ?? Calories? Or ??Joules?1 B.Th.U ?? Calories? Or ??Joules?

1 kWh = ?? Calories? Or ?? B.Th.U?

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Introduction

Thomas A. Edison opens Pearl St. Station, NYCWaterwheel-driven dc generator

installed in Appleton, Wisconsin

First transmission lines installed

1882

1882

1882

Frank J. Sprague produces dc motor for Edison systems

Nikola Tesla presents paper on two-phase ac induction and synchronous motors

in Germany (2400 V dc, 59 km)

William Stanley develops commercially practical transformer

First single-phase ac transmission line in US,

1884

1885/6

1888

1889

1882

First three-phase ac transmission line in Germany (12 kV, 179 km)

transmission line in US, in Oregon (4 kV, 21 km)

First three-phase ac transmission line in US, in California (2.3 kV, 12 km)

1891

1893

Frequency standards for power systems

Introduction

60 Hz

North America, Brazil, Japan and

400 Hz

On board of ships, airplanes

16 2/3 Hz or 25 Hz

Railway application

50 Hz

Most of the countries

, , ppart of Thailand

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Sources of Electric Energy

Conventional/ Primary SourcesFossil Fuels

Coal

Oil (Diesel/ Petroleum)

Natural Gas

Nuclear power

Hydropower

R bl / S d SRenewable/ Secondary SourcesGeothermal power

Solar power

Wind powerTidal power

BiomassEnergy Harness/ Harvest


Coal – fossil fuel extracted from the ground

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Natural Gas – gaseous fossil fuel consisting primarily of methane


Nuclear power – steam is produced by heating water through a process called nuclear fission

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Hydropower – is a process in which flowing water is used to spin a turbine connected to a generator


Geothermal power – is electricity generated by utilizing naturally occurring geological heat sources

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Solar power – describes a number of methods in harnessing energy from the light/heat of the Sun


Wind power – is derived from the conversion of the energy contained in wind into electricity

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Biomass – (wood, agricultural waste, such as rice husk and bagasse, are some other energy sources for producing electricity.


Energy Harness – Piezoelectric, Hydrodynamic, Tree power, pyroelectricity, ocean/sea wave energy

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3 AC/HVDC/

FACTS


Distributed GenerationMicrogrid

Modern Power System

Renewable Energies

Smart Grid

Deregulation System

Restructuring System

3 AC/ HVDC/ FACTS• Modern electric power systems is mainly

operating based on 3-phase AC basis


operating based on 3-phase AC basis.

• High Voltage Direct Current (HVDC) Transmission is used especially for interconnected system, sub-marine system, and very long distance transmission (> 800 km).

• Flexible AC Transmission System (FACTS) is• Flexible AC Transmission System (FACTS) is used to improve transmission quality and efficiency of AC Grid by supplying necessity amount of reactive power to the grid.

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Malaysia-Thailand 300MW HVDC Interconnection


230kV

275kV

Main Components of TNB-EGAT HVDC Transmission


TNBAC

System

EGATAC

System

DC transmission line

HVDC converter station

Converter transformer

Harmonic filter & capacitor banks

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Renewable Energies/ Distributed Generation

Distributed generation is an approach that


• Distributed generation is an approach that employs small-scale power generation plant to produce electricity close to the end consumer of power.

• Example: Solar plant, CHP (Co-p p , (generation), wind farm, biomass power plant, etc.


Distributed

Electric Utility or

Grid System

End Consumer

Site

Distributed Generation

(Solar, wind, biomass, hybrid system…)

System

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RegulatedMonopolised power market based on the down lawsbased on the down laws and regulations set by the government.

DeregulatedR t t th l t iRestructure the electric industry so that power production and retail sales are competitive.

• Regulated power system


• Deregulated power system

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Smart Grid

• The Smart Grid is a combination of hardware,


management and reporting software, built atop anintelligent communications infrastructure.

• In the world of the Smart Grid, consumers and utilitycompanies alike have tools to manage, monitor andrespond to energy issues.

• The flow of electricity from utility to consumer becomes atwo-way conversation saving consumers money energytwo-way conversation, saving consumers money, energy,delivering more transparency in terms of end-user use,and reducing carbon emissions.


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Why Smart Grid?

•• IntegrateIntegrate isolated technologies : Smart Grid enables b tt t


better energy management.• Proactive management of electrical network during

emergencyemergency situations.• Better demand supply / demand responseresponse management.• Better power qualitypower quality• Reduce carboncarbon emissions. • Increasing demanddemand for energy : requires more complexIncreasing demanddemand for energy : requires more complex

and critical solution with better energy management


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Microgrid

Mi id b i ll lf t i d l t i l


• Microgrids are basically self-contained electrical ecosystems.

• Power is produced, transmitted, consumed, monitored, and managed all on a local scale.

• In many cases, they can be integrated into larger, central grids, but their defining characteristic is that they can operate independently if disconnected from the whole.


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Power Flow


• Steady state analysis• Fundamental analysis for the

rest of power system analysis• Time domain analysis

Basic Analysis

FaultDynamics

p y y

• Short circuit• Open circuit• Overload

• Time domain analysis of instantaneous electrical events

StabilityTransient

• Angular stability• Voltage stability• Steady state stability• Dynamic stability• Transient stability

• Analysis of electrical events with the time response of ms or less such as lightning strike

Power System Analysis, Computing and Economics


• Computing applications• Distribution system analysis• Economics, market organisation, cost structures,

pricing, and risk management• Intelligent system applications• Reliability, uncertainty, and probability and

stochastic system applications

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Power System Dynamic Performance

• Power system dynamic modeling: components


Power system dynamic modeling: components and systems

• Power system stability: phenomena, analysis, and techniques

• Power system stability controls: design and applicationsP t d i t• Power system dynamic measurements

• Power system interaction with turbine generators• Dynamic security assessment: techniques and

applications, risk-based methods

Power System Operations

• Energy control centers


Energy control centers• Distribution operation• System control• Operating economics and pricing

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Power System Communications

• Communication systems


Communication systems• Communication media• Communication protocols• Communication standardisation• Home automation and communication

Power System Protection

• Digital protection systems


Digital protection systems• Adaptive protections• Power system protection• Protection of electrical equipment• Relaying communications• Relaying for consumer interfacey g• Design/testing of high voltage surge protective

devices (>1000V)• Design/testing of low voltage surge protective

devices (<1000V)

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Some power system simulation tools…

EMTDC/PSCAD


• EMTDC/PSCAD

• ETAP (Power Station)

• ERACS

• DigSILENT (Power Factory)

• PowerWorld

• PSS/E and PSS/Adept (Siemens)• PSS/E and PSS/Adept (Siemens)

• EasyPower

• MATLAB / Simulink (SimPowerSystems™)

• PSAT (Open source)

• MathCAD, Excel, Pspice…

Main Utility Company

Power Systems in Malaysia

Independent Power Producers (IPP)

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Energy Generation According to Fuel Mix in Malaysia - 2012


Natural Gas 44.5%

Hydro 15.5%

Medium Fuel Oil 0.6%Distillate 3.3%

Coal 36.1%

Total installed generation capacity as of 31st December

2012 was 21,749 MW.

Sectoral percentage contribution for year 2012


Peak power demand as of 31st December 2012

was 15,826 MW.

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Power Demand


Long Term Load Forecast


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Generation Mix


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• Sabah Grid


• Sarawak Grid


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• Voltage Criteria– Steady-State Voltage Fluctuation (Normal Condition):


Voltage level % variation

– Steady-State Voltage Fluctuation (Contingency Condition)


415V and 240V -10% & +5%

6.6kV, 11 kV, 22kV,33kV +/- 5%

132kV and 275kV -5% & +10


415V and 240V +/- 10%

6.6kV, 11 kV, 22kV,33kV +10 & -10%

132kV and 275kV +/- 10%

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• Low Voltage:– Single-phase, two-wire, 240V, up to 12 kVA

maximum demand


maximum demand

– Three-phase, four-wire, 415V, up to 45 kVAmaximum demand

– Three-phase, four-wire, C.T. metered, 415V, up to 1,000 kVA maximum demand

• Medium and High Voltages:– Three-phase, three-wire and 11 kV for load of

1 000 kVA maximum demand and above


1,000 kVA maximum demand and above

– Three-phase, three-wire, 22kV or 33kV for load of 5,000 kVA maximum demand and above

– Three-phase, three-wire, 66kV, 132kV and 275kV for exceptionally large load of above275kV for exceptionally large load of above 25 MVA maximum demand

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• Frequency Criteria– The supply frequency is 50 Hz ± 1%


Asean Power Grid Plan


Documents

BEF 25503 Power Systems Chapter 1 - author.uthm.edu.myauthor.uthm.edu.my/uthm/www/content/lessons/2779/Chapter 1.pdf · • PSS/E and PSS/Adept (Siemens)PSS/E and PSS/Adept (Siemens)