Asset Integrity Monitoring of Wind Turbine Blades with Non-Destructive Radar Sensing

Abstract

Global growth in onshore and offshore wind energy has created a forecasted 11.5% Compound Annual Growth Rate (CAGR) increase in Wind Turbine (WT) blades throughout 2020-2025. The ability to verify blade condition throughout the asset lifecycle is integral to economic and reliable renewable energy supplies. Currently, commercial inspection of deployed wind turbine blades is predominately performed by rope access personnel using visual and infrared cameras. In this paper we present the results of Frequency Modulated Continuous Wave (FMCW) radar analysis of a decommissioned wind turbine blade exhibiting clearly defined defects. We show that FMCW sensing provides a non-invasive, non-destructive and non-contact means of surface and sub-surface integrity evaluation of these composite structures. We observe absolute unit (a.u.) order of magnitude contrasts for healthy blades at 0.47 x106 (a.u.) versus defective blade structures at 1.9 x105 (a.u.). Our results present the analysis of the decoupled reflected electromagnetic wave, verifying FMCW sensitivity to different failure modes relating to surface and internal structures of the WT blade. The FMCW analysis of WT blades demonstrated within this paper represents a first in instantaneous cross-sectional analysis of blade assets, providing a transformative advancement in WT blade integrity analysis.