TY - RPRT
T1 - Quantification of Linear Torque Characteristics of Cup Anemometers with Step Responses
AU - Pedersen, Troels Friis
PY - 2011
Y1 - 2011
N2 - This report outlines a method for determination of torque characteristics of cup anemometers based on a partial linear model of torque coefficient relationship. The work was undertaken as part of the UPWIND project part 1A2.1 on metrology, and was identified as needed for revision of the IEC61400-12-1 standard on power performance measurements. The step response model of the IEA-11 document intrinsically leads to linear torque coefficient curves for step responses from low or high speed ratios. The slopes of the linear torque coefficient curves can thus be determined from the step response time constants. The standard ISO 17713-1 recommends step response data in the speed ratio range 30-75% to be used. This seems to be in a range that is outside of the usual range being used in classification according to IEC61400-12-1. In practice, a range closer to equilibrium speed ratios should be used; 50-98% for speed-up step responses and 150-102% for speed-down step responses. A stepwise procedure is proposed, where the step response method may be improved by adding more inertia to the rotor to extend the data and to reduce torque ripples due to the cups.
AB - This report outlines a method for determination of torque characteristics of cup anemometers based on a partial linear model of torque coefficient relationship. The work was undertaken as part of the UPWIND project part 1A2.1 on metrology, and was identified as needed for revision of the IEC61400-12-1 standard on power performance measurements. The step response model of the IEA-11 document intrinsically leads to linear torque coefficient curves for step responses from low or high speed ratios. The slopes of the linear torque coefficient curves can thus be determined from the step response time constants. The standard ISO 17713-1 recommends step response data in the speed ratio range 30-75% to be used. This seems to be in a range that is outside of the usual range being used in classification according to IEC61400-12-1. In practice, a range closer to equilibrium speed ratios should be used; 50-98% for speed-up step responses and 150-102% for speed-down step responses. A stepwise procedure is proposed, where the step response method may be improved by adding more inertia to the rotor to extend the data and to reduce torque ripples due to the cups.
U2 - 10.11581/DTU.00000310
DO - 10.11581/DTU.00000310
M3 - Report
T3 - DTU Wind Energy I
BT - Quantification of Linear Torque Characteristics of Cup Anemometers with Step Responses
PB - Risø National Laboratory
CY - Risø, Roskilde, Denmark
ER -