Calibration of torque measurement under constant rotation in a wind turbine test bench

Abstract

Abstract. To determine the efficiency of multi-MW wind turbines, the torque measurement in wind turbine test benches has to be performed with an accuracy better than 0.2 %. To this end, the torque measurement has to be traced to national standards in the MN m range. This can be done by using a novel torque transfer standard in combination with a newly developed torque calibration procedure under constant rotation, which are both presented and discussed in this paper. The calibration procedure was performed on a 4 MW wind turbine test bench and the evaluation of the calibration result, including a measurement uncertainty, is explained in detail.

Efficiency Measurement With a Focus on the Influence of Rotation and Temperature on Torque Measurements Performed on Small-Scale Test Benches

“…The objective of this study is to explore the influences of rotational operation and temperature on torque measurements and hence their effect on the direct efficiency determination (IEC 60034-2-1 [6]) of the four-pole squirrel-cage asynchronous machine (ASM) (Table 1). To further investigate the dependencies, the efficiency determination of the ASM at speeds of 150 min -1 , 500 min - [6], [7], and [8] In the applied method, the efficiency of the rotating ASM operating in generator mode is determined by directly measuring the electrical power 𝑃 elec and the output power 𝑃 mech . The subscript G is used in this paper to denote generator mode operation.…”

“…Figure 1: Stepwise changes of the load torque at different rotational speeds for efficiency measurement based on[6],[7], and[8] …”

5.1.3 Torque calibration in the MN m range under rotation in a nacelle test bench

“…4: Additional uncertainty contributors considered in the total measurement uncertainty (cf. [14]). As expected, the expanded measurement uncertainty (Tab.…”

Data Measuring System for Torque Measurement on Running Shafts Based on a Non-Contact Torsional Dynamometer

“…Torsional dynamometers are divided into strain-gauge [3,[5][6][7][10][11][12] and torque [4,8,9,[13][14][15][16][17][18]. Work process of the torsional torque dynamometer, in contrast to the torsional strain-gauge dynamometer, is based on direct or indirect measurement of a twisting angle of the torsional shaft.…”

“…Devices designed to measure the torque can be divided into four classes according to the principle of operation: cradle dynamometers, torsional indicators, transmission dynamometers and transducers for measuring by extrinsic parameters . Torsion dynamometers are usually inertialess instruments and perform only the measuring function, enabling to record both the time averages and ever-varying values of the engine torque during its operation in any modes [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18].…”