Investigating wind turbine dynamic transient loads using contactless shaft torque measurements

Abstract

The wind industry is showing increasing awareness about the importance of long‐term direct shaft mechanical torque measurements to fully understand wind turbine (WT) dynamics, adopt proactive solutions for extreme load mitigation and enhance condition monitoring (CM) capabilities. Although torsional effects are important, torque measurement on such large, inaccessible machines is practically and logistically difficult, mainly because of the costly and intrusive specialised equipment currently available. This study details an experimental set‐up for the investigation of shaft dynamic transient load and speed measurements through a contactless, low‐cost torque meter. Results are obtained over a range of applied loads and compared with reference measurements from an in‐line, invasive torque transducer. Average torque and speed root‐mean‐square error values of 0.53 Nm and 0.35 rpm, respectively, indicate good accuracy of the proposed contactless torque meter. Its implementation in the field would allow direct, cheap, real‐time measurements of WT drive train loads for performance monitoring, control and CM purposes.