Evaluation of dynamic testing of full-scale wind turbine drivetrains with hardware-in-the-loop

Abstract

Dynamometer testing of full-scale wind turbine drivetrains involves subjecting integrated components to extreme static loads, fatigue loads, or dynamic loads to replicate field conditions. This paper provides a detailed evaluation of the uncertainty and errors in applied loads and measured responses, and their magnitude relative to established repeatability bounds for a drivetrain subjected to static and dynamic loads on the 7.5 MW test bench at the Clemson University Wind Turbine Drivetrain Testing Facility. An ideal drivetrain simulation model is utilized to isolate the influence of load tracking errors on test article responses. It is shown that the test article response variations are mainly driven by run out and clearances inherent to the drivetrain. For the dynamic profiles, the load tracking errors are within acceptable limits. A frequency analysis is used to show that the test bench controller tracking performance is acceptable for profiles with frequency content up to 1.5 Hz.

Multi-Degree-of-Freedom Load Reproduction by Electrohydraulic Digital-Servo Loading for Wind Turbine Drivetrain

“…The maximum nominal error is approximately 25 kN forces and 25 kNm moments, or roughly 5% of the requested signals' amplitude for a specific test profile [13]. Bibo et al provided a comprehensive assessment of the uncertainty and inaccuracies in applied loads and measured responses, as well as their significance relative to established predefined limits for repetition for a drivetrain exposed to both static and dynamic loads on the 7.5 MW test bench [14]. The experimental results were applied to evaluate the tracking error on the test bench and the cross-coupling occurring between bending moments and forces [15].…”