Upload
imran-ahmed
View
2.554
Download
2
Embed Size (px)
DESCRIPTION
Small wind turbine and hybrid system
Citation preview
SMALL WIND TURBINE AND HYBRID SYSTEM
SMALL WIND TURBINES AND HYBRID SYSTEM
Upswing for last two or three years
Main drivers to its growth are:
– Demand supply gap in energy;– Increase in fossil fuel prices;– Diverse applications for which it can be used both for standalone and grid tied.
Useful for powering small loads at remote locations particularly having weak or no grids.
Useful for commercial application – Telecommunication towers
Can serve as miniature power plants
SMALL WIND TURBINES/AEROGENERATORS
• Based on rotor swept area
• Based on axis of rotation
• Based on direction of wind
• Based on forces acting on rotor
CLASSIFICATIONS:
SMALL WIND TURBINES/AEROGENERATORS
Rated power (kW) Rotor swept area (m2)
Sub-category
Prated < 1 kW A < 4.9 m2
(1.25m Dia)Pico wind turbine
1 kW < Prated< 7 kW A < 40 m2
( 3.6m Dia) Micro wind
turbine
7 kW < Prated< 50 kW A < 200 m2
( 7.9m dia)Mini wind turbine
or SWT
Based on rotor swept area:
Standard referred IEC 61400-2 – Design requirements of small wind turbines.
- Defines small wind turbines as systems with rotor swept area smaller than 200 sq.m, generating at a voltage below 1000 V a.c or 1500 V d.c.
SMALL WIND TURBINES/AEROGENERATORS
Based on axis of rotation
Horizontal Axis Wind turbine
• Propeller type rotor is mounted on a horizontal axis.
• The rotor is positioned into the wind direction by means of a tail wane or active yaw motor
Vertical Axis Wind turbine
• Omni directional • No yaw mechanism required • Gearbox and electrical generator housed
near the ground• Requires guy wire support• Power output cannot be controlled during
high winds by changing the blade pitch
Darrieus Type Savonius Type
Horizontal Axis Wind turbine
Upwind Machine
SMALL WIND TURBINES/AEROGENERATORS
Based on direction of wind:
• Rotor faces the wind • Avoid wind shades behind the tower
Downwind Machine• Rotor is placed on the lee side of the tower• Can be built without yaw mechanism• Rotor is more flexible and has less weight• Better structural dynamics
• Based on forces acting on wind turbine
• Lift Type • Drag Type
- If the tip speed ratio (TSR) > when then SWT has some amount of lift- If TSR < 1 then SWT is drag type
- Savonius rotors are drag type machine - Darrieus rotors are lift type turbine
Global Scenario:
SMALL WIND TURBINES/AEROGENERATORS
In the year 2008, the total number of small wind turbine spectrum was 19000 units amounting to 33.6 MW installations.
Application World total by 2008
No. % kW %
Off-grid 13,902 73.48 7,536 22.5
On-grid 4,992 26.42 26,065 77.5
Total 18,89
4 100
33,601
100.0
Distribution of SWT installations in 2008, by applications
SMALL WIND TURBINES/AEROGENERATORS
SMALL WIND TURBINES/AEROGENERATORS
Indian Scenario
Total cumulative capacity of hybrid system is about 1110 kW
SMALL WIND TURBINES/AEROGENERATORSShares of States in Wind-Solar-Hybrid systems
SMALL WIND TURBINES/AEROGENERATORSOff-Grid / Standalone systems
Control schemes for variable speed operationConstant tip speed ratio scheme
T.S.R = ωR/V
• Wind speeds are measured locally and optimal rotor speed is computed using reference TSR.
• Optimal rotor speed is compared to the actual rotor speed and the electrical loading is adjusted to correct the difference.
Maximum power extraction using the constant tip speed ratio scheme
SMALL WIND TURBINES/AEROGENERATORSOff-Grid / Standalone systems
Control schemes for variable speed operationPeak Power Tracking scheme dP ---- = 0 dω
Maximum power extraction using the peak point extraction scheme
• Rotor speed is incrementally varied by small amount and by evaluating dP/dω the peak power tracking scheme continuously tracks the optimal operating point and adjust rotor speed accordingly
SMALL WIND TURBINES/AEROGENERATORSOff-Grid / Standalone systems
Photovoltaic System
Peak power tracking photovoltaic module
SMALL WIND TURBINES/AEROGENERATORSOff-Grid / Standalone systems
Peak Power Tracker
I-V Curve
Power output of the PV module is P = V · I watts. Operation moves away from the above point, such that the current is now I +∆Ivoltage is V +∆V, the power output will be
P + ∆ P = (V+∆V).(I+∆I)∆P = ∆V.I+V. ∆I At the peak point, ∆P = 0
is the dynamic impedance, and is the static impedance of the source
SMALL WIND TURBINES/AEROGENERATORSOff-Grid / Standalone systems
Charge ConverterBuck Converter Step down DC to DC
converter
Voltage across the inductor
During ON time, ∆ IL. L = (Vin- Vout).Ton
During OFF time, ∆ IL. L = Vout .Toff
Vout = Vin.D
Where D is the duty cycle
D = Ton/T and T = Ton + Toff
Out put voltage is always < that of the input voltage
SMALL WIND TURBINES/AEROGENERATORSOff-Grid / Standalone systems
Charge ConverterBoost Converter
Step up DC to DC converter
Voltage across the inductor
During ON time, ∆ IL. L = Vin .Ton
During OFF time, ∆ IL. L = (Vout – Vin).Toff
Vout = Vin/1-D
Where D is the duty cycle
D = Ton/T and T = Ton + Toff
Out put voltage is always > that of the input voltage
SMALL WIND TURBINES/AEROGENERATORSOff-Grid / Standalone systems
Charge ConverterBuck Boost Converter
Buck and Boost converter combined together in cascading is the buck boost converter.
Buck boost converter used for variable speed wind machines for battery charging either by stepping up or stepping down the voltage
SMALL WIND TURBINES/AEROGENERATORSOff-Grid / Standalone systems
Battery
• Energy storage option used for standalone system
• Consists of electro-chemicals cells connected in series-parallel combination
to achieve the desired operating voltage and current.
• Cell capacity measured in Ah• Battery rating in specifically in terms of average
voltage during discharge and its Ah capacity.
• Charging a 600 Ah battery at C/10 rate means charging at 60 A.• Discharging that battery at C/2 rate means draining 300 A• Preferred batteries used for wind-solar-hybrid systems:
• Lead-acid (Pb-acid). • Nickel-metal hydride (NiMH).• Nickel-cadmium (NiCd).
SMALL WIND TURBINES/AEROGENERATORSGRID CONNECTED SYSTEMS
Grid connected wind system Grid connected PV system
ROLE OF C-WET
To evaluate the performance of the small wind turbines based on the following tests:
1. Power performance measurement 2. Duration test 3. Safety and function test
To empanel the small wind turbines with MNRE based on an evaluation of their safety philosophy, engineering integrity, quality assurance and results of the type tests (if conducted).
TYPE TESTING OF SMALL WIND TURBINES/AEROGENERATORS
TYPE TESTING
SAFETY AND FUNCTION TEST
POWER PERFORMANCE
TEST
DURATION TEST
OTHER TESTS(EMC,
ENVIRONMENTAL)
TYPE TEST CONFORMITY STATEMENT
The objective of the type test is to provide data needed to verify aspects which are vital to safety and therefore need additional experimental verification, and aspects which cannot be reliably evaluated by analysis.
SMALL WIND TURBINE TESTING SET UP
POWER PERFORMANCE TESTThe Power Performance is carried in accordance to the IEC standard, Wind Turbine Generator Systems, Part 12: Power performance Measurement Techniques, IEC 61400-12-1 DC power output of the turbine will be
measured. Wind speed Vs DC Power to be plotted. Power curve validates the manufacturer’s
performance claims over a range of wind speeds, aggregated over time.
Estimation of annual energy production helps in determining the amount of energy likely to be generated per annum, for a specific average wind speed.
0 2 4 6 8 10 12 14 16 180
100
200
300
400
500
600
700
Wind Speed (m/s)
Elec
trica
l Pow
er (W
)
2 4 6 8 10 12 14 160
0.02
0.04
0.06
0.08
0.1
0.12
Wind Speed (m/s)CP
DURATION TEST The purpose of the duration test is to investigate Structural integrity and material degradation Environmental / dynamic behaviour of wind turbine
Criteria satisfying the duration test as per IEC 61400-2 reliable operation during the test period for a minimum
period of 6 months of operation;
at least 2 500 h of power production in winds of any velocity; at least 250 h of power production in winds of 1.2 Vave and
above; at least 25 h of power production in winds of 1.8 Vave and
above.
SAFETY AND FUNCTION TEST The purpose of safety and function testing is to verify
that the wind turbine under test displays the behavior predicted in the design and that provisions relating to personnel safety are properly implemented.Power and Speed control – turbine has blade angle of 150 which regulates the speed of turbine• Yaw control - to check yawing / yawing movement
starts at a given wind speed• Loss of load – to check when the loads are removed
suddenly whether the turbine current reduces to zero.
• Over speed protection – to check how it regulates the speed of rotor. Turbine status will be sensed to verify if dump load switches on for RPM > 200.
• Start up – To check the automatic start up operation at a cut in wind speed of 2.5 m/sec.
• Shutdown above design wind speed – at 7 m/sec the machine starts furling.
• Emergency stop under normal operation – Time series of DC power, RPM, Turbine status signal will be plotted.
0
10
20
30
40
50
60
TimePo
wer
12 13 14 15 16 17 18 19400425450475500525550575600625650
Wind speed [m/s]
Max
pow
er
shut down above design wind speed
power and speed control
Wind Solar Hybrid Systems installed at C-WET
Small wind turbines in conjunction with solar photo voltaic system can be used in remote places( with weak grids and high winds) not connected to the grid, to meet the basic power requirements
Systems installed at C-WET Wind at C-WET : 4.0 m /s annual average Solar insolation : 700 W/ sq.m
(1) 25 kW Wind Solar Hybrid system(2) 5 kW wind Solar DG Hybrid System using intelligent
controller
25 kW Wind Solar Hybrid System Specifications:
15 kWp solar photovolatic system5 kW small wind turbines, 2 nos.Grid supported system288 V, 600 Ah battery back upAverage load 10 kWCost of the system : Rs 100 lakhs
Single line diagram of PCU
5 kW Wind-Solar-DG Hybrid System 5 kW Wind-Solar-Diesel Hybrid System- Proof of concept to provide uninterrupted power through intelligent, economical and optimized renewable sources - To monitor the generation, consumption and performance parameters through GPRS based remote monitoring.
Specifications: - Solar panel capacity: 1.8kW (peak)- Aerogenerator : 3.2 kW - Battery capacity: 48 Nos. of 600 Ah- DC link voltage : 48 V- DG set: 5 KVA- Cost of the system : Rs 20 lakhs
• Traditional megawatt power production in electricity is insufficient both for industrial growth and higher living standards.
• Micro-generation can act as a catalyst for cultural changes in consumer attitude.
• Output of solar photovoltaic system can be more reliably predicted, say 4 units/ day for 1 kW system.
• Small wind turbines need to be installed after a careful evaluation of the wind at the site, predicted output for the particular site and information on performance of the particular model.
CONCLUSION
THANKS