Hydrostatic Drive Train in Wind Energy Plants · Hydrostatic Drive Train in Wind Energy Plants ......
Transcript of Hydrostatic Drive Train in Wind Energy Plants · Hydrostatic Drive Train in Wind Energy Plants ......
Hydrostatic Drive Train inWind Energy Plants
Johannes Schmitz, Nils Vatheuer14.03.2011
generator 1
generator 2
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Englisch
Outline
Introduction
Configuration of the transmission
Measurement results from the test bench
Outlook and Conclusion
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IFAS: Institute for Fluid Power Drives and Controls
0 2 4 6 8 10 12-200
0
200
400
F Fr [N
]
0 2 4 6 8 10 12-200
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400
F Fr [N
]
0 2 4 6 8 10 12-200
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400
F Fr [N
]
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Continuously variable transmission ratio Good damping characteristics Save and reliable operation
Basic idea of the hydrostatic transmission
Development and testing of a hydrostatic drive train for wind turbines
Important hydraulic features
Overall efficiency Costs of energy
To be evaluated
Task for IFAS
Problems with reliability ofmechanical gearboxes
Grid stability
Motivation
Axial piston motor
Radial piston pump
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Outline
Introduction
Configuration of the transmission
Measurement results from the test bench
Outlook and Conclusion
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Generation of different concepts
Concepts generated in morphological box
Evaluation and optimisation in simulations
Adaption to wide range of power is important Good efficiency at high pressure and full displacement Cascading of pumps and motors is beneficial Combination with mechanical transmission can increase power density Not possible in our time frame
Evaluation
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Two hydraulic circuits Three different modes of operation Components
2 pumps (70 & 280 kNm)
3 variable displacement motors
1 constant motor
2 generators
Chosen configuration for 1 MW
321
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Simulation result: overall efficiency
63 simulation runs Wind speed
2,6 – 15 m/s
1 MW turbine model simulates torque on the drive train Existing efficiency data of components had to be scaled
Boundary conditions
Schmitz, J., Vatheuer, N., Murrenhoff, H.,Development of a Hydrostatic Transmission for Wind Turbines, Proceedings of 7.IFK, Aachen, 2010
Simulated operating points
2 3 4 5 6 7 8 9 10 11 12 13 14 15wind speed [m/s]
0102030405060708090
100ov
era l
l effi
cien
cy [%
]
0
200
400
600
800
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pow
er[k
W]
turbine poweroverall efficiency
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Simulation result: dynamic characteristics
70 71 72 73 74 75 76 77 78 79 80time [s]
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350
torq
u e [k
Nm
]
30.6
30.8
31
31.2
31.4
31.6
31.8
32
rota
tion
s pee
d [rp
m]
torque from windtorque turbine shaftturbine rotation speed
Torque impulses are smoothened
Hydrostatic transmission has a low stiffness Turbine can accept small changes in rotation speed
10 of 18Hydrostatic Drive Train in WEPJ. Schmitz, N. Vatheuer
Englisch
Outline
Introduction
Configuration of the transmission
Measurement results from the test bench
Outlook and Conclusion
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Englisch
Integration into the 1 MW test bench
Hydrostatic transmission
generator 1
generator 2
Hydrostatic transmission
motor 1
motor 2
High torque at low speed
Dynamic loads
Limited electrical power
Challenges
Hydrostatic power feed-back
Generators replaced by electrical motors and axial piston pumps
Turbine is simulated by radialpiston motor
Drive is controlled by variable displacement pumps
Test bench layout
Test bench drive Hydrostatic transm.
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Measurement result 1/2
Test bench drive applies torque Transmission controller adjusts the
rotation speed
Procedure of the measurement
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0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32rotation speed [rpm]
0102030405060708090
100
over
all e
ffic i
enc y
[%]
Measurement result 2/2
generator 1
generator 2
generator 1
generator 2
generator 1
generator 2
Torque is applied dependent on rotation speed (turbine characteristics)
Transmission controller controls the rotation speed
Procedure of the measurement
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Outline
Introduction
Configuration of the transmission
Measurement results from the test bench
Outlook and Conclusion
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Englisch
Outlook: simulation of wind turbine environment
Hardware-in-the-Loop Dynamic wind loads Drive train controller
Hydrostatic transmission
motor 1
motor 2
Measurements under realistic conditions
Adaptation of standard components Switching strategy
Transmission optimisation
Transplant the transmission into a pilot wind energy plant
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Outlook: proposal for multi-megawatt turbine
Doubling the power four times more pump displacement
Hydraulic pumps are not available yet Approach: Upstream mechanical
transmission
Challenge with multi-megawatt transmissions
Mechanical ratio: 4.5 Four independent hydraulic modules 1.25 MW per module
5-MW-Concept
Combining the benefits of mechanical and hydraulic drive trains
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Evaluation so far Resistance against pulsing torque loads, protection against overload Variable transmission ratio allows the usage of a synchronous generator
without a frequency converter Components and operating strategy open up a wide area for improvements
Conclusion
Hydrostatic drive train can be adapted to WEP power-curve Simulation and measurement results match at high power 85 % overall efficiency throughout a wide power range Switching off individual units can improve efficiency at partial load
Thank you for your attention.Questions, Suggestions?
J. Schmitz, N. Vatheuer14.03.2011
generator 1
generator 2
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Englisch
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Englisch
Test bench
Test bench drive Hydrostatic transmission
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Q_P2
V5
Q_P2zuP1
Q_P1zuP2
Ventil_P1zuP2
RSV_P2zuP1
Q_DBV_P2
DBV_P2
HD_M1
Schlauch_P2
Schlauch_P1
Q_P1
p_HD
M3
M2
M1
M4
Leckage_M1
Leckage_M3
Leckage_M4
Leckage_M2
H2SpQ
Stellzeit_M4
Stellzeit_M3
Stellzeit_M2
Stellzeit_M1
S5123
Antriebsleistung_P2Antriebsleistung_P1
Motor3
HD
ND T
Motor4
HD
ND T
Wirkungsgrad_M4
Wirkungsgrad_M3
Wirkungsgrad_M2
Leistungsverlust_M4
Leistungsverlust_M3
Leistungsverlust_M2
Antriebsleistung_M4
Antriebsleistung_M3
Antriebsleistung_M2
Motor2
HD
ND T
Motor1
HD
ND T
Wirkungsgrad_P2
Leistungsverlust_P2
Wirkungsgrad_P1
Leistungsverlust_P1
Leckage_P2
M_Verlust_P2M_Verlust_P1
Leckage_P1
Pumpe2
PPumpe1
P
RSV M4
RSV M3
V_M4
V_M3
Ventil_M4
Ventil_M3
RSV M2
V_M2
Ventil_M2
RSV M1
V_M1
Ventil_M1
schw_M3
schw_M2
schw_M4
Q_Ventil_P1Q_Ventil_P2
HD_P2V_P1
RSV_P1
Ventil_P2Ventil_P1
P2_ausP1_aus
Blasenspeicher2
Q_DBV_ND
Q_ND
ND1RohrND
HD_M234
schw_M1
Leistungsverlust_M1Antriebsleistung_M1
Wirkungsgrad_M1
Q_DBV_P1
ND2
Speisepumpe
DBVstatisch2
HD_P1
DBV_P1
Rotorwelle
Resonant frequency
1 2
Bode-plot
34.11570.0 rpmHz
Hzf
JCV
HH
RH
PH
570.02
22
Analyses
Theoretical
Simplified model
Without leakage
Including Leakage
Complete transmission model
Pumpe
P
pump
RSV
DBV
ND
HD
DM
1 2
frequency [Hz]