Evaluation of the uncertainty of a traceable efficiency determination method for wind turbine electrical machines in a small-scale test bench

Abstract

This paper examines the feasibility and practicability of international standards for determining the efficiency of wind turbine electrical machines on a test bench. Test methods combined with static calibration certificates from specialized instruments and sensors were used to evaluate the efficiency and determine the measurement uncertainty (MU) values in ambient conditions on a small-scale test bench (SSTB). These will next be studied on the nacelle test bench (NTB). The main test used to determine the performance of wind turbines is the direct efficiency method. For comparison, two other tests were done applying the indirect and modified back-to-back (MBTB) efficiency methods based on small-scale test bench measurements for wind turbines. The results were compared with a focus on MU values and are presented in this paper.