Precision blade deflection measurement system using wireless inertial sensor nodes

Abstract

Structural health monitoring on wind turbine blades is a great enhancement for operational safety and failure avoidance. Blade deflection is a key parameter, which is a function of blade geometry and material properties. The absolute blade deflection is affected by wind load, gravitational, and centrifugal forces and must exceed neither material stress limits nor tower clearance. In this paper, we introduce a novel method for real time reconstruction of blade movement using inertial measurement units (IMUs) located at defined positions along the blade. An algorithm is introduced that combines IMU measurements and a priori information of the fundamental blade mode shapes to accurately reconstruct the blade movement. A low‐power wireless sensor node for blade deflection monitoring is presented. The autonomous sensor node is equipped with an IMU together with a low‐power wireless transceiver and powered by a compact translational electromagnetic energy harvester. Sufficient energy is harvested each rotor revolution for continuous measurement data streaming within the wind turbine's operating range. A data stream of six‐axis IMU measurements enables real time, three‐dimensional reconstruction of the entire blade movement in the back end positioned in the tower. The reconstruction of blade tip deflection is possible even under high wind turbulences with a minimum accuracy of 0.22 m for an onshore 5 MW and 0.58 m for an offshore 15‐MW reference turbine. The complete system has been tested thoroughly under conditions similiar to a real wind turbine. Realistic stimulation of the reconstruction algorithm is performed by means of OpenFAST simulations.

Research on transmission line dance monitoring and early warning system by fusing multi inertial sensors

“…Literature [21] equipped with a low-power wireless transceiver, algorithms combining IMU measurements and a priori information about the shape of the basic blade modes, proposed a lowpower wireless sensor node for blade deflection monitoring, thus utilizing wireless inertial sensors for structural health monitoring of wind turbine blades. Literature [22] incorporates the use of inertial sensors.…”

Autonomous Sensor System for Low-Capacity Wind Turbine Blade Vibration Measurement

“…Other works proposed using optical method sensors to detect abnormal states in a rotor system as a whole through fiber-optic sensing [ 15 ], employ cost-effective three-dimensional digital image correlation to monitor the blades’ structural health [ 16 ], or use a laser-Doppler vibrometer system for modal parameter identification [ 17 ]. Finally, more recent works have proposed using a Doppler radar sensor for feature extraction and fault detection [ 18 ] or blade deflection using novel wireless inertial measurement units [ 19 ].…”

Looseness Identification of Transmission Tower Based on Inertial Measurement

“…The approach effectively facilitates the detection of damage along the track by introducing the damage index. Grundkötter et al [13] utilize data collected from six-axis IMU and incorporates prior knowledge of fundamental blade vibration modes. This integration enables precise monitoring of the health status of wind turbine blades, exemplifying an approach to applying IMU in the context of renewable energy technology.…”