CHAPTER 1

INTRODUCTION TO POWER SYSTEM

MALAYSIA POWER SYSTEM

OVERVIEW

NATIONAL GRID

• HV electric power transmission in Peninsular Malaysia, operated and owned by TNB.

• Malaysia’s electric utility companies with state grids:(a) Tenaga Nasional Berhad (TNB) – National Grid(b) Sabah Electricity Sdn. Bhd. (SESB)

(c) Sarawak Electricity Sdn. Bhd (SESCO)• Electricity generation stations:

(a) TNB(b) Independent Power Producer (IPP)HV=high voltage

HISTORY

1964 •Bangsar Power Station was connected to the Connaught Bridge Power Station, with the line subsequently extended to Malacca

•Connaught Bridge Power Station in Klang was the precursor of the energy grid

1965

•A plan was set to connect the electricity generating plants that were spread out all over the country.

•Perak - Temengor, Kenering, Bersia, Batang Padang•Selangor - Connaught Bridge, Kapar , Serdang•PAKA (Terengganu), Cameron Highlands (Pahang), Perai (Penang), Port

Dickson (Negeri Sembilan), Pergau (Kelantan), Pasir Gudang (Johor and Malacca)

1980•The loop was complete with the placement of Kota Bharu within the grid.

GENERATION

All figures are in megawattsSource: Suruhanjaya Tenega (Energy Commission) Annual Report

62.620.9

9.5 7

GENERATION

GASCOALHYDROOTHERS

TRANSMISSION

• 132kV, 275kV and 500kV• The 500 kV transmission system is the single

largest transmission system to be ever developed in Malaysia.

• The National Grid is linked via 132 kV HVAC and 300 kV HVDC interconnection to Thailand (300MW) and 230 kV submarine cables to Singapore (200MW).

DISTRIBUTION

• 33 kV, 22 kV, 11 kV, 6.6 kV and 415V/240V

ENERGY POLICIES

• The energy policy of Malaysia is determined by the Malaysian Government, which address issues of energy production, distribution, and consumption.

• Government-linked companies PETRONAS and TNB are major players in Malaysia's energy sector.

• Governmental agencies are: (a) Ministry of Energy, Green Technology and Water(b) Energy Commission (Suruhanjaya Tenaga) (c) Malaysia Energy Centre (Pusat Tenaga Malaysia).

GENERATION OF ELECTRICITY

Importance of

ElectricityConvenient energy form

Easiness to control

Flexibility Cheapness

Cleanliness

High transmission

efficiency

Importance of Electricity• Convenient energy form

-It can be converted from one energy form into any other form.-Eg: bulb glows when electricity passes through it (conversion of electrical energy into light energy)

• Easiness to control-An electric motor can be started or stopped by turning ON or OFF a switch.

• Flexibility-It can be easily transported from one place to another by using conductor.

Importance of Electricity

• Cheapness-It is much cheaper than other forms of energy and economical to use for domestic, commercial, and industrial purposes.

• Cleanliness-It has no smoke, fumes, and poisonous gases.

• High transmission efficiency-It can be transmitted efficiently from the centre of generation to the consumers by using transmission lines.

ENERGY SOURCES FOR GENERATION

ENERGY SOURCES

Renewable Energy

Sun

Wind

Water

Non-renewable Energy

Fuel

Coal

Nuclear

SUN (SOLAR)• Solar power is the conversion of sunlight into

electricity, either directly using photovoltaic (PV), or indirectly using concentrated solar power (CSP).

• This heat can be used to produce steam and then electrical energy with the combination of turbine-generator.

• Limitations:-It is not economical because it requires a large area for the generation of small amount of electrical power.-It cannot be used in cloudy days or night.

CSP & PV

The PS10 concentrates sunlight from a field of heliostats on a central tower.

Nellis Solar Power Plant in US, one of the largest PV power plants in North America.

The PS10 concentrates sunlight from a field of heliostats on a central power.

WIND

• The conversion of wind energy into a useful form of energy.

• Eg: wind turbines to make electricity, windmills for mechanical power, wind-pumps for water pumping, or sails to propel ships.

• Limitations:-Unreliable because of uncertainty about wind pressure.-Power generated is quite small.

WIND

Wind power generators in Spain, near an Osborne bull.Aerial view of Lillgrund

Wind Farm, Sweden

WATER

• The kinetic energy of flowing water can also be used to spin turbines to generate electricity.

• Limitations:-It involves high capital cost due to construction dam.-There is uncertainty about the availability of huge amount of water due to dependence on weather conditions.

WATER

Bakun DamThe Gordon Dam in Tasmania is a large hydro facility, with an installed capacity of 430 MW.

FUEL

• The main sources of energy are fuels, solid fuel as coal, liquid fuel as oil and gas fuel as nature gas.

• When the fuels are burnt, they release the heat energy to produce mechanical energy and later electrical energy.

• Limitations:-Can contribute the air and water pollution.-High maintenance cost

FUEL

Montana's Natural Gas & Coal Fired Generation. Coal-fired power plants in Jewett,

Texas.

NUCLEAR

• Nuclear energy means the part of the energy released by fusion or fission of URANIUM generate steam which drives the steam turbine-generator to produce electricity.

• Limitations:-High cost of nuclear plant-Problem of disposal of radioactive waste-Dearth of trained personnel to handle the plant.

NUCLEAR

Nuclear power plants often have huge cooling towers.

COMPARISON OF ENERGY SOURCES

No Particular Water-power Fuels Nuclear energy

1 Initial cost High Low Highest

2 Running cost Less High Least

3 Reserves Permanent Exhaustible Inexhaustible

4 Cleanliness Cleanest Dirtiest Clean

5 Simplicity (Cooling system)

Simplest Complex Most complex

6 Reliability Most reliable Less reliable More reliable

TYPES OF POWER PLANT

HYDRO POWER PLANT

Russian “Sayano-Shushenskoe” (yep it’s hard to read name) hydro electric power plant is the biggest hydro power plant in Russia

Outflow during a test at the hydropower plant at the Hoover Dam, located on the Nevada-Arizona border.

TYPICAL LAYOUT

DAM was built on a large river that has a

large drop in elevation.

It stores lots of water behind it in the RESERVOIR.

WATER INTAKE is near the bottom

of the dam.

Gravity causes the water to fall through the PENSTOCK inside

the dam.

The water turns the TURBINE which then

turns the SHAFT of the generator.

Electricity is generated and passed through the power lines to

consumers.

OPERATION

FUNCTION OF THE MAIN COMPONENTS

A turbine converts the energy of flowing water into mechanical energy.

A generator converts this mechanical energy into electricity according to Faraday’s Law.

When the rotor turns, it causes the field poles to move past the conductors mounted in the stator.

This, in turn, causes electricity to flow and a voltage to develop at the generator output terminals."

HYDRO ELECTRIC GENERATOR

PUMPED STORAGE

THERMAL / STEAM POWER PLANT

TYPICAL LAYOUT

SCHEMATIC LAYOUT

The heat is used to generate steam which drives a steam turbine connected to a generator which produces electricity.

OPERATION

The coal in the COAL STORAGE is delivered to the coal handling plant to crushed it into small pieces.

The coal is fed to the BOILER by belt conveyors.

The coal is burnt in the boiler and the ash produced after the combustion is delivered to the ash pond for disposal.

The heat of combustion convert water into steam at high temperature and pressure.

OPERATION (CONT.)

The dry and superheated steam from the super heater is fed to the steam turbine through the valve.

The heat energy of steam when passing over the blades of turbine is converted into mechanical energy.

The turbine is coupled to a generator which converts mechanical energy into electrical energy.

After it passes through the turbine, the steam is condensed in the condenser and recycled to where it was heated (Rankine Cycle).

NUCLEAR POWER PLANT

SCHEMATIC LAYOUT

OPERATION

Nuclear power station

use a fuel called

URANIUM

It is formed

into LONG RODS and submerge in water to kept them

cool.

When they are

removed from water, the uranium atom is split

into two and

released RADIATION and HEAT.

STEAM is produced and then fed to a steam

turbine.

The generator converts kinetic energy

supplied by the turbine

into electrical energy.

After it passes

through the

turbine, the steam

is condensed in the

condenser

The water is then

pumped again into

nuclear reactor and the

cycle begins again.

ADVANTAGES & DISADVANTAGES OF VARIOUS POWER PLANT

No

Item Steam power station Hydro-electric power plant

Diesel power plant Nuclear power plant

1 Site/ location

Located at a place where ample supply of water and coal is available, transportation facilities are adequate

Located where large reservoirs can e obtained by constructing a dam such as in hilly areas

Located at any place because they require less space and small quantity of water

Located away from thickly populated areas to avoid radio active pollution

2 Initial cost Lower than hydroelectric and nuclear power plant

high Less as compared to other plant

highest

3 Running cost

Higher than hydroelectric and nuclear power plant

low Highest among all plants

Minimum cost

4 Limit of source of power

Limited reserves Not dependable because of wide variations in the rainfall every year

Limited reserves Available in sufficient quantity

5 Cooling system

Need more water to cooling the system and need a big system to cooling the system

Need less water to cooling the system because just cooling for the oil only

Use the gas reactor cooler

6 Environmental pollution

Air pollution because of ash and sulfur dioxide

Water and noise pollution

Pollution cause the radio active

THREE PHASE SYSTEM CONFIGURATION

GENERATION OF 3-PHASE EMF

• 3 coils RR1, YY1 and BB1 are fixed 1200 apart.• Ends of each coil are connected to the slip rings.• The coils rotated anti-clockwise in a uniform magnetic

field between the poles “N” and “S”.• EMF generation depends upon the position of the coil

with respect to the magnetic field.• For the position in the above figure, EMFRR1=0V.

• When moved by 900, EMFRR1= max . EMFYY1 and EMFBB1 have same magnitude as EMFRR1 but lag by 1200 and 2400 respectively.

GENERATION OF 3-PHASE EMF

VECTOR DIAGRAM OF 3ϕ SYSTEM

SINGLE-LINE DIAGRAM (SLD)

• SLD is a graphical representation of electrical circuit drawn using single line instead of drawing 3 separate lines for 3 phases.

• Elements on the diagram do not represent the physical size or location of the electrical equipment.

SLD SYMBOLS

SLD DIAGRAMSLD DIAGRAM

LoadG

Step up transformer

Transmission line

Step down transformer

Figure 1.7 : Single line diagram of simple electrical power system

IMPEDANCE DIAGRAM FOR 3Φ GENERATOR

ELECTRICAL ENERGY DEMAND

• Energy Demand is the maximum amount of electrical energy that is being consumed at a given time.

• It is measured in kilowatts (kW) and kilovolt ampere (kVA).

• Energy Consumption is the total electricity used for a period of time.

• It is measured in kilowatts hour (kWh).• Eg: A 1000W loads used for one hour consumes one

kilowatts hour.

ENERGY DEMAND vs ENERGY CONSUMPTION

LIGHTING EXAMPLE : -One 100W light bulb burning for 10 hours consumes 1,000 Wh @ 1 kWh. -The entire time it is on, it requires or "demands" 100W @ 0.1 kW from the utility. -That means the utility must have that 0.1 kW ready whenever the customer turns the lamp on.

ENERGY DEMAND vs ENERGY CONSUMPTION

- Similarly, ten 100W light bulbs burning for 1 hour consume 1,000 Wh @ 1 kWh. -In both examples, the consumption is 1 kWh, however, look how differently the second situation impacts the utility from a demand perspective. -The serving utility must now be prepared to provide ten times as much 'capacity' in response to the "demand" of the 10 light bulbs operating all at once.

ENERGY DEMAND vs ENERGY CONSUMPTION

• A device which taps electrical energy from electric power system is called a LOAD on the system.

• The load may be resistive, inductive, capacitive or some combination of them.

VARIABLE LOAD ON POWER STATION

Types of Loads

Domestic Load

Commercial Load

Industrial Load

Municipal Load

Irrigation Load

Traction Load

VARIABLE LOAD ON POWER STATION

LOAD CURVE

• Connected Load- It is the sum of continuous ratings of all the equipments connected to supply system.

• Maximum Demand- It is the greatest demand of load on the power station during a given period.

• Demand Factor- It is the ratio of maximum demand on the power station to its connected load.

TERMS

LoadConnectedDemandMaxFactorDemand .

• Average Load / Average Demand- The average of loads occurring on the power station in a given period (day or month or year).

TERMS

• Load Factor- The ratio of average load to the maximum demand during a given period.

TERMS

• Diversity Factor- The ratio of the sum of individual maximum demands to the maximum demand on power station.

TERMS

• DEFINITION- A term that used to discuss the events in electric power grids that can damage or disrupt sensitive electronic devices.

• Occur due to the increased use of power electronic devices in industrial and commercial sector which are more sensitive to voltage variations.

POWER QUALITY

• Variations in the peak or RMS voltage. - When the rms voltage exceeds the nominal voltage, the event is called “VOLTAGE SWELL”. - when the rms voltage is below the nominal voltage, the event is called “VOLTAGE SAG”.

• Undervoltage - occurs when the nominal voltage drops below 90% for more than 1 minute.

• Overvoltage- occurs when the nominal voltage rises above 110% for more than 1 minute.

• Random or repetitive variations in the RMS voltage between 90% and 110% of nominal can produce a phenomenon known as "flicker" in lighting equipment.

FACTORS AFFECTING POWER QUALITY

• Variations in the frequency• Variations in the wave shape – usually described as

harmonics. • Nonzero low-frequency impedance - when a load draws more power, the voltage drops.• Nonzero high-frequency impedance

- when a load demands a large amount of current, then stops demanding it suddenly, there will be a dip or spike in the voltage due to the inductances in the power supply line.

FACTORS AFFECTING POWER QUALITY

VOLTAGE WAVEFORMS

METHODS TO ENHANCE PQ

METHODS TO ENHANCE PQ