introduction to power system operation
TRANSCRIPT
-
8/11/2019 Introduction to Power System Operation
1/39
Introduction to Power SystemOperation
Power Generation and Economics
-
8/11/2019 Introduction to Power System Operation
2/39
Power Generation
Fundamental of Energy Source Power System Behavior Energy Transfer in Power System
Economics Maximum Demand, Demand Factor Diversity Factor
Plant Capacity Factor Annual Plant Use Factor Load Sharing Between Generating Station
-
8/11/2019 Introduction to Power System Operation
3/39
Fundamental of Electric Source : Theory ofPower Generation
Associated very close to Left Hand Rule
Magnetic flux
N S
Cutting the flux lines
Induce current
-
8/11/2019 Introduction to Power System Operation
4/39
-
8/11/2019 Introduction to Power System Operation
5/39
Steam pushes theturbine blades
Blades cut throughmagnetic flux
Current induced;
electric produced
-
8/11/2019 Introduction to Power System Operation
6/39
Steam generation
Steam is a vaporized air with certain speed, andtemperature
It contains a lot of energy and circulates inside
Rankine Cycle.
It is resulted from energy changing from one form toanother
-
8/11/2019 Introduction to Power System Operation
7/39
General arrangement of fossil fuel facility
-
8/11/2019 Introduction to Power System Operation
8/39
High pressure and high temperature stream rotatesteam turbine and generate electric power
-
8/11/2019 Introduction to Power System Operation
9/39
As steam rotates turbine, it loses energy. And asresult its pressure and temperature are greatlyreduced
-
8/11/2019 Introduction to Power System Operation
10/39
The steam is then changed into liquid (water) bya condenser. Condenser eliminates heat into itssurrounding
-
8/11/2019 Introduction to Power System Operation
11/39
Liquid is the goes into compressor inlet to regainhigh pressure.
-
8/11/2019 Introduction to Power System Operation
12/39
High pressure water is added with hightemperature through boiling process. Fuel (coal/nuclear) boils the high pressured water
-
8/11/2019 Introduction to Power System Operation
13/39
High temperature and pressure steam produced,and rotates turbine to generate electric power
-
8/11/2019 Introduction to Power System Operation
14/39
-
8/11/2019 Introduction to Power System Operation
15/39
Spin the turbineat prime move(excl. solar
direct
conversion type)
Generateelectric powerby flux rotationin function of
time
V = N (d / dt)
Energy Sources
Common andtraditionalConventional
Source
Also known
as renewableenergy sourceGreenSource
-
8/11/2019 Introduction to Power System Operation
16/39
Source ofenergy
Conventional
Coal
Nuclear
Water
Renewable
Solar
Wind
Biofuels
Oceantemperature
-
8/11/2019 Introduction to Power System Operation
17/39
Source ofenergy Turbine
Transmission
lineLoad
Source ofenergy
Rotation ofturbine
( 2 f)
Generatorexcitation currentic increase flux,
Increasevoltage V = N
(d / dt)
Produce electricpower
To load throughtransmission
line
-
8/11/2019 Introduction to Power System Operation
18/39
Energy Transfer in Power System
Combustion of coal, rapid movement of water,pressurized gas / steam, produce energy to spin theturbine
Spin of turbine generates electric power
However, for large and high concentrated areasneed power stability. Combined cycle or coal arepreferred. Hydro and solar are usually ruled out.
-
8/11/2019 Introduction to Power System Operation
19/39
At the event of massive load reduction, generatorsense increase of voltage
Turbine has to slow down the rotation to limit outputTo limit rotation, frequency of turbine needs to bereduced
Massive load increase, generator sense reduction ofvoltageTurbine needs to increase rotation to produceincrease inputFrequency of turbine to be increase
-
8/11/2019 Introduction to Power System Operation
20/39
However, under both circumstances, changes ofvoltage/ frequency produce oscillations
This oscillation needs to be managed for the systemto return to stability condition
Management of oscillations requires collaborationsof power system parameters (security,communication, etc)
-
8/11/2019 Introduction to Power System Operation
21/39
Energy transfer using steam/gas
Boilers (place of combustion coal, gas, oil) producesteam at high temperature and pressure
Steam goes into turbines. Spinning turbines results
in electric power.
Rankine cycle is preferred (modified to include superheating, feed water heating, and steam reheat
-
8/11/2019 Introduction to Power System Operation
22/39
Coal Fired Power Plant (Steam/Gas)
-
8/11/2019 Introduction to Power System Operation
23/39
Nuclear Power Plant (Steam)
-
8/11/2019 Introduction to Power System Operation
24/39
Energy transfer using water
Oldest form of energy conversion
Energy is FREE, thanks to gravity and water atomicbuilt
However, building hydro power plant need massivecost and must consider geographic surface
-
8/11/2019 Introduction to Power System Operation
25/39
Hydro Power Plant (Water)
-
8/11/2019 Introduction to Power System Operation
26/39
Power available from hydro power plant is calculate-able by (assuming efficiency is 100%):
P = (1.0) gWH (Watt)
Where:
is the density of water = 1000 kg/m 3 g is the gravity rate = 9.81ms -2
H is the Head measured in m (height of
upper water level above lower)W is the flow rate (m 3/s) through turbine
-
8/11/2019 Introduction to Power System Operation
27/39
Example:
Average flow of a river is 575m3/s and type ofdesired turbine is Kaplan. Assuming that the powerto be extract is 100% of the capacity of Kaplanturbine, and efficiency of the system is 100%,determine the power to be developed per cubic
meter per second.
Solution:
Kaplan turbine : 100% capacity = 61m (H up to 61m)Efficiency, n = 100%Water density = 575 m3/sGravitational force = 9.81m/s2
-
8/11/2019 Introduction to Power System Operation
28/39
Pelton
Heads (H) 184m 1840m
Bucket wheel rotorand adjustableflow nozzles
Francis H = 37 490m Mix flow type
Kaplan H = up to 61m Only run of river/
pondage station
-
8/11/2019 Introduction to Power System Operation
29/39
Francis hydro turbine Pelton hydro turbine Kaplan hydro turbine
-
8/11/2019 Introduction to Power System Operation
30/39
Sea tides also can be utilized to produce electricpower. This has been done in Scotland where thewater is rocky and tides are consistently hardthroughout the year
Sea tide produces electric power as :
P = () gh 2 A (Watt) * A = area of waterin water basin
-
8/11/2019 Introduction to Power System Operation
31/39
Energy transfer using solarHuge solar power plant in France produces electricpower through heat radiation
The farm includes thousands of sun light deflectors
which deflect sun light to one tall boiler
Heat generated, in turn is used to produce steam forthe turbines
-
8/11/2019 Introduction to Power System Operation
32/39
Solar Power Plant (Steam/Gas)
-
8/11/2019 Introduction to Power System Operation
33/39
Energy collected from one per square meterdeflector is :
q = I ( F + B) (T4 T40)
I is the incident radiation normal to surface
F and B is the front and back emissivitiesof absorber
is the absorptive of panel is the transmittance of cover plate is the Stefan Boltzmann constant
-
8/11/2019 Introduction to Power System Operation
34/39
Energy transfer through windBy utilizing speed of wind, generation of electricpower is possible
Wind turbine is positioned at the optimum area
where speed and concentration of wind is atmaintained
Stable wind speed is preferred to its high speed
-
8/11/2019 Introduction to Power System Operation
35/39
Higher towers, blades produce high outputs butcomes at extra cost. Power generated by wind is asfollows
P = AU 3 (Watt)
Where
is the air density = 1.201 kg/m 3
U is the air velocity (m/s ) A is the swept area of blade (m)
-
8/11/2019 Introduction to Power System Operation
36/39
TutorialCalculate the number of wind generators required toproduce equivalent of 600MW. Please assume windspeed is 10kmh or 2.78 ms-1, blade diameter is20m, and conversion efficiency is 45%
Given :
Blade diameter, d = 20mWind speed, U = 2.78 ms-1
-
8/11/2019 Introduction to Power System Operation
37/39
Wind power, P can be calculated
P = AU3
= (1.201) ( (20/2) 2) (2.78x10-3)= 4053kW
Since conversion efficiency is at 45%, thus totalpower generated
P = 4053kw x 45% = 1823kW
-
8/11/2019 Introduction to Power System Operation
38/39
Since one wind turbine produce 1823KW, thus toproduce equivalent of 600MW, number of turbineneeded is:
Number of turbine = 600MW / 1823KW= 330 turbine
-
8/11/2019 Introduction to Power System Operation
39/39
TutorialIn a new 25m depth built reservoir, power isgenerated through 5 turbines and is deliveredthrough a transmission line system to support lightlocal load. Due to fluctuation of incoming watersource, minimum water level is recorded at 55% ofmaximum. Determine required power generated perturbine.
Given the water flow rate is 70m3
/s during maximumwater level and 35m 3/s during minimum water level.