ram....elec 1

8/8/2019 ram....elec 1

http://slidepdf.com/reader/full/ramelec-1 1/29

1

Training Session on EnergyTraining Session on Energy

EquipmentEquipment

ElectricityElectricity

©© UNEP 2006UNEP 2006

Electrical

Equip

ment/

Electricity

8/8/2019 ram....elec 1


2

©© UNEP 2006UNEP 2006

Training Agenda: ElectricityTraining Agenda: Electricity

• Future electricity scenario

• Generation & distribution

• Phase of electricity

• Active and reactive power

• Power factor correction

• Electrical load management

• Electrical billing mechanisms

• Transformers

Electrical

Equip

ment/

Electricity

8/8/2019 ram....elec 1


3

©© UNEP 2006UNEP 2006


• Development can be measured by a

nation’s electricity consumption• Electricity usage is divided into:

a) Industrial

b) Commercial and residential

c) Agriculture and irrigation

• Electricity important input for industry

General Electricity ScenarioElectrical

Equip

ment/

Electricity

8/8/2019 ram....elec 1


4

©© UNEP 2006UNEP 2006


International Energy Agency predicts for 2030:

• 78% of population in developing countrieshas access to electricity

• 1.4 billion people no access

• 665 billion US$ needed to overcome this

General Electricity ScenarioElectrical

Equip

ment/

Electricity

8/8/2019 ram....elec 1


5

©© UNEP 2006UNEP 2006


• How can electricity supply shortage

be solved?a) Renovation and modernization of plants,

transmission and distribution systems

b) Demand side management with theutilization of energy efficiencytechnologies

c) Awareness raising among energy users

General Electricity ScenarioElec

trical

Systems/

Electricity

8/8/2019 ram....elec 1


6

©© UNEP 2006UNEP 2006


• Electricity generation: fossil fuels anduranium

• Renewable energy is growing

Generation & DistributionElec

trical

Systems/

Electricity

Renewable 21%

Nuclear 16%

Fossil fuels 63%

World electricity generation byenergy

(US Energy Information Administration, 2004)

8/8/2019 ram....elec 1


7

©© UNEP 2006UNEP 2006


Elec

trical

Systems/

Electricity

Generation & Distribution

Generator

10.6 KV

GT220 KV

Step downtransformer

Distribution

Power plant Transmissionsystem

Distribution system

8/8/2019 ram....elec 1


8

©© UNEP 2006UNEP 2006


• AC generators (“alternators”) generateelectricity

• Electricity generated at 9-13 KV

• Power generated from 67.5 to 1000 MW

• Power stations: generating transformers

(GTs) to increase voltage to 132-400 KV

• Substations: step-down transformers toreduce voltage before distribution

Elec

trical

Systems/

Electricity


8/8/2019 ram....elec 1


9

©© UNEP 2006UNEP 2006


Benefits of high voltage transmission

• Less voltage drop: good voltage regulation• Less power loss: high transmission

efficiency

• Smaller conductor: lower costs

Elec

trical

Systems/

Electricity


8/8/2019 ram....elec 1


10

©© UNEP 2006UNEP 2006


Single phase AC circuit:

• Two wires connected

to electricity source• Direction of current

changes many timesper second

Phase of ElectricityElec

trical

Systems/

Electricity

3-phases of an electric system(Wikipedia contributors, 2005)Three phase systems:

• 3 lines with electricity from 3 circuits

• One neutral line

• 3 waveforms offset in time: 50-60 cycles/second

8/8/2019 ram....elec 1


11

©© UNEP 2006UNEP 2006


Star connection

Phase of ElectricityElec

trical

Systems/

Electricity

Delta connection

8/8/2019 ram....elec 1


8/8/2019 ram....elec 1


13

©© UNEP 2006UNEP 2006


Power Factor CorrelationElec

trical

Systems/

Electricity

Figure: Power factor of electric circuit

8/8/2019 ram....elec 1


14

©© UNEP 2006UNEP 2006


• kVAR demand should be as low aspossible for the same kW output

PF Correction: CapacitorsElec

trical

Systems/

Electricity

Figure: Capacitor as kVAR generator

8/8/2019 ram....elec 1


15

©© UNEP 2006UNEP 2006


• Act as reactivepower generators

• Reduce reactive

power • Reduce total

power generatedby the utilities

PF Correction:CapacitorsE

lec

trical

Systems/

Electricity

Figure: Fixed capacitor banks

Source: Ecatalog

8/8/2019 ram....elec 1


16

©© UNEP 2006UNEP 2006


Advantages for company:

• One off investment for capacitor • Reduced electricity costs:

• Total demand reduced

• No penalty charges• Reduced distribution losses

• Increased voltage level at load end, improvedmotor performance


trical

Systems/

Electricity

8/8/2019 ram....elec 1


17

©© UNEP 2006UNEP 2006


Advantages for utility:

• Reduced reactive component of network

• Reduced total current in the system fromthe source end

• Reduced I2R power losses• Reduced need to install additional

distribution network capacity


trical

Systems/

Electricity

8/8/2019 ram....elec 1


18

©© UNEP 2006UNEP 2006


• Goal: reduce maximum electricity demandto lower the electricity costs

• Load curve predicts patterns in demand

Electrical Load ManagementElec

trical

Systems/

Electricity

Daily load curve of anengineering industry(National Productivity

Council, India)

K V A

Hours

8/8/2019 ram....elec 1


19

©© UNEP 2006UNEP 2006


Strategies to manage peak load demand:

•Shift non-critical / non-continuous processloads to off-peak time

• Shed non-essential loads during peak time

• Operate in-house generation or diesel generator

(dg) sets during peak time• Operate AC units during off-peak times and

utilize cool thermal storage

• Install power factor correction equipment

Electrical Load ManagementElec

trical

Systems/

Electricity

8/8/2019 ram....elec 1


8/8/2019 ram....elec 1


21

©© UNEP 2006UNEP 2006


• Power factor penalty or bonus

• Fuel costs

• Electricity duty charges

• Meter rentals

• Lighting & fan power consumption

• Time of Day (TOD) rates

Electricity Billing MechanismElec

trical

Systems/

Electricity

8/8/2019 ram....elec 1


22

©© UNEP 2006UNEP 2006



trical

Systems/

Electricity

Utility uses trivector meter for measurementduring billing cycle (usually month):

• Maximum demand

• Active energy in kWh

•Reactive energy in kVArh

• Apparent energy in kVAh

8/8/2019 ram....elec 1


23

©© UNEP 2006UNEP 2006



trical

Systems/

Electricity

• Demandmeasured in timeintervals

• Maximumdemand ishighest reading

• Customer charged onhighestmaximumdemand value!

A Typical Demand Curve (National Productivity Council)

8/8/2019 ram....elec 1


24

©© UNEP 2006UNEP 2006


• Static electrical device thattransforms electrical energyfrom one voltage level toanother

• Two or more coils linkedmagnetically but electricallyinsulated

Transformer Elec

trical

Systems/

Electricity

• Turns Ratio: turns on 2nd coil (connected to load)

turns on 1st coil (connected to power source)

Figure 12: A view of atransformer (Indiamart.com)

8/8/2019 ram....elec 1


25

©© UNEP 2006UNEP 2006


Transformers are classified based on:

• Input voltage

• Operation

• Location

• Connection

Transformer typesElec

trical

Systems/

Electricity

8/8/2019 ram....elec 1


26

©© UNEP 2006UNEP 2006


• Transformer losses: constant and variable

• Best efficiency: load where constant loss =

variable loss

Transformer Losses & EfficiencyElec

trical

Systems/

Electricity

Transformer loss versus percent loading (BEE, 2004)

PTOTAL = PNO-LOAD + (% Load/100)2 x PLOAD

PTOTAL = PNO-LOAD + (Load KVA/Rated KVA)2 x PLOAD

8/8/2019 ram....elec 1


27

©© UNEP 2006UNEP 2006


Electricity FormulaeElec

trical

Systems/

Electricity

• Resistance (Ohm)

• Voltage (Volts)

• Reactance

• Impedance

• Real power (Watt)

• Reactive power

• Apparent power

• Power factor

• Efficiency

• Transformer ratio

• Voltage drop in aline

• Star connection

• Delta connection

8/8/2019 ram....elec 1


28

Training Session on EnergyTraining Session on Energy

EquipmentEquipment


THANK YOUTHANK YOU

FOR YOUR ATTENTIONFOR YOUR ATTENTION

©© UNEP GERIAPUNEP GERIAP

Elec

trical

Systems/

Electricity

8/8/2019 ram....elec 1


29

Elec

trical

Systems/

Electricity

Disclaimer and ReferencesDisclaimer and References

• This PowerPoint training session was prepared as part of

the project “Greenhouse Gas Emission Reduction from

Industry in Asia and the Pacific” (GERIAP). While

reasonable efforts have been made to ensure that the

contents of this publication are factually correct and properly referenced, UNEP does not accept responsibility

for the accuracy or completeness of the contents, and shall

not be liable for any loss or damage that may be occasioned

directly or indirectly through the use of, or reliance on, the

contents of this publication. © UNEP, 2006.

• The GERIAP project was funded by the Swedish

International Development Cooperation Agency (Sida)

• Full references are included in the textbook chapter that is

available on www energyefficiencyasia org

ram....elec 1

Documents