Thu, 18 June, 2020
Wind energy is one of the fastest growing sectors in the world's energy markets. However, wind turbine blades are susceptible to fatigue failure and adverse environmental effects. The most cost-effective maintenance strategy to ensure healthy and functional blades is to employ a condition monitoring system to assess blade status continuously. This means that blade defects can be detected at an early stage, and fixed quickly, effectively at a low cost. Unattended blade cracks will grow and propagate under fatigue loading, eventually leading to blade failure that requires a costly blade replacement.
Aiming to develop and validate a condition monitoring system for wind turbine blades, five companies including TWI, Renewable Advice, EWT, Halliburton and ASSIST formed the BladeSave consortium to combine their expertise in structural health monitoring (SHM), fibre optic sensing technology as well as management software that incorporates risk based blade data analysis.
The BladeSave system features an innovative design, which offers multi-sensing capabilities including acoustic emission (AE), vibrations and strain, achieved with Fibre Bragg Grating (FBG) sensors. This all-optic design brings the benefits of system’s immunity to static electricity, EMI noise and lightning. BladeSave also combines a blade management software (windmanager) linking the data from inspection and maintenance to the SHM data, offering a comprehensive solution for wind turbine blade monitoring, repair and management.
The BladeSave system has been successfully demonstrated in a wind turbine from project partner EWT for more than 3 months, during which time the system has obtained long-term operational profiles described by processed SHM data including AE, vibration and strain. The BladeSave system has been tested for ice accretion on blade surfaces with simulated mass. The testing results showed evident detection capabilities.
The final stage of this project entails destructive testing on a wind turbine blade to be conducted at TWI. The BladeSave system will be installed to monitor the process with a commercial system employed for comparison. For this testing, controlled cyclic loading will be applied repetitively to gradually simulate blade crack initiation and propagation. It is expected that the system will demonstrate its capabilities to detect cracks in early stages and support maintenance decision making.
The BladeSave project has received funding from the European Union’s Horizon 2020 programme under grant agreement No 760353.