Abstract
Variable speed operation of a wind turbine has a number of advantages. However there are some problems too. Two of these problems are the mechanical resonance of the drive train and a possible commutation failure of the line commutated convertor resulting from a grid fault. In variable speed wind turbines the damping of mechanical vibrations at the eigenfrequency of the drive train is low. At this frequency, which lays typically in the range of 1 to 10 Hz, the gain of the transfer function of wind speed to torque increases by a factor 5 to 10 compared to the gain at lower frequencies. If this increase is reduced to a factor 1.25, a considerable reduction in gearbox rating is possible. This reduction could be achieved by adding mechanical damping, which will increase the investment cost of the turbine considerably. In the IRFLET project this reduction has been obtained by control of the electromagnetic torque. A multi-input single-output (MISO) controller has been designed, using a model of a variable speed system with synchronous generator and DC-link, obtained by system identification techniques. The model is validated against experimental results. Results of this control, implemented on a 20 kW system on a test-rig,
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Pierik, J T.G.;
Van Engelen, T G;
[1]
Bongers, P M.M.;
Van Baars, G E
[2]
- Unit ECN-Renewable Energy, Netherlands Energy Research Foundation, Petten (Netherlands)
- Systems and Control Group, Department of Mechanical Engineering, Delft Univ. of Technology, Delft (Netherlands)
Citation Formats
Pierik, J T.G., Van Engelen, T G, Bongers, P M.M., and Van Baars, G E.
Damping of mechanical resonance and protection against grid failure for variable speed wind turbines (IRFLET).
Netherlands: N. p.,
1992.
Web.
Pierik, J T.G., Van Engelen, T G, Bongers, P M.M., & Van Baars, G E.
Damping of mechanical resonance and protection against grid failure for variable speed wind turbines (IRFLET).
Netherlands.
Pierik, J T.G., Van Engelen, T G, Bongers, P M.M., and Van Baars, G E.
1992.
"Damping of mechanical resonance and protection against grid failure for variable speed wind turbines (IRFLET)."
Netherlands.
@misc{etde_10127371,
title = {Damping of mechanical resonance and protection against grid failure for variable speed wind turbines (IRFLET)}
author = {Pierik, J T.G., Van Engelen, T G, Bongers, P M.M., and Van Baars, G E}
abstractNote = {Variable speed operation of a wind turbine has a number of advantages. However there are some problems too. Two of these problems are the mechanical resonance of the drive train and a possible commutation failure of the line commutated convertor resulting from a grid fault. In variable speed wind turbines the damping of mechanical vibrations at the eigenfrequency of the drive train is low. At this frequency, which lays typically in the range of 1 to 10 Hz, the gain of the transfer function of wind speed to torque increases by a factor 5 to 10 compared to the gain at lower frequencies. If this increase is reduced to a factor 1.25, a considerable reduction in gearbox rating is possible. This reduction could be achieved by adding mechanical damping, which will increase the investment cost of the turbine considerably. In the IRFLET project this reduction has been obtained by control of the electromagnetic torque. A multi-input single-output (MISO) controller has been designed, using a model of a variable speed system with synchronous generator and DC-link, obtained by system identification techniques. The model is validated against experimental results. Results of this control, implemented on a 20 kW system on a test-rig, are compared to results without control to illustrate the improved mechanical behaviour. The second of the above-mentioned problems can result in a considerable increase of the direct current, which causes an increased electromagnetic torque as well as an increased shaft torque, and eventually the rupture of the fuses. To prevent this increase in current and torque a protection algorithm has been designed and implemented in the process computer, monitoring the DC-link voltage at the line commutated convertor every millisecond. If a potential short circuit situation is detected, the firing angle of the machine commutated convertor is increased instantaneously to reduce the current, followed by the reduction of the excitation voltage.}
place = {Netherlands}
year = {1992}
month = {Jan}
}
title = {Damping of mechanical resonance and protection against grid failure for variable speed wind turbines (IRFLET)}
author = {Pierik, J T.G., Van Engelen, T G, Bongers, P M.M., and Van Baars, G E}
abstractNote = {Variable speed operation of a wind turbine has a number of advantages. However there are some problems too. Two of these problems are the mechanical resonance of the drive train and a possible commutation failure of the line commutated convertor resulting from a grid fault. In variable speed wind turbines the damping of mechanical vibrations at the eigenfrequency of the drive train is low. At this frequency, which lays typically in the range of 1 to 10 Hz, the gain of the transfer function of wind speed to torque increases by a factor 5 to 10 compared to the gain at lower frequencies. If this increase is reduced to a factor 1.25, a considerable reduction in gearbox rating is possible. This reduction could be achieved by adding mechanical damping, which will increase the investment cost of the turbine considerably. In the IRFLET project this reduction has been obtained by control of the electromagnetic torque. A multi-input single-output (MISO) controller has been designed, using a model of a variable speed system with synchronous generator and DC-link, obtained by system identification techniques. The model is validated against experimental results. Results of this control, implemented on a 20 kW system on a test-rig, are compared to results without control to illustrate the improved mechanical behaviour. The second of the above-mentioned problems can result in a considerable increase of the direct current, which causes an increased electromagnetic torque as well as an increased shaft torque, and eventually the rupture of the fuses. To prevent this increase in current and torque a protection algorithm has been designed and implemented in the process computer, monitoring the DC-link voltage at the line commutated convertor every millisecond. If a potential short circuit situation is detected, the firing angle of the machine commutated convertor is increased instantaneously to reduce the current, followed by the reduction of the excitation voltage.}
place = {Netherlands}
year = {1992}
month = {Jan}
}