Structural Integrity Monitoring of the Critical Zones in the Wind Turbine Composite Blades with the Use of Integrated Sensors—SESS Project

Abstract

The wind turbine blade is the second most expensive part of a wind turbine, constituting 20-22% of the total cost. According to one study, during the lifetime of a wind turbine, rotor blades contribute to 34% of overall system downtime. Associated maintenance costs, by some estimates, are 1.5-2% of a new generation wind turbine investment. All of these affect the profitability of wind generation. This paper presents modern approach for structural integrity monitoring and damage detection in the wind turbine blades. Composite structure of the blade is affected by the environmental issues and cycling load. These lead to possibility of occurrence different failure modes affecting structural integrity of composite as well as bond joints. For that reason during the quality control in manufacturing as well as for inservice inspection appropriate techniques must be applied to monitor such structures. This article assume integrated sensors approach with the use of elastic waves generation for the bonding joint monitoring of the wind turbine blade. One of the proposed solution is the SESS system. The SESS – Smart Embedded Sensor System is the health monitoring system for the assessment the integrity of the critical zones in the wind turbine blade. The SESS is designed to be a system for early damage detection which will:  Focus on ‘hot spots’ located on the wind turbine blade;  Identify key damage types which are associated with selected ‘hot spots’;  Give the user an appropriate knowledge base and analysis tool to assess the damage and schedule repairs and maintenance on an asneeded basis. Article presents the design of the state of the art system with sensors array which will be integrated with the blade. Moreover the information about the algorithms, data processing, hardware solutions will be delivered. The most important will be the information about the verification tests in the lab as well as on the component (blade).