Wind power generation is a kind of green energy technology, which has the advantages of renewable resources, no pollution and so on. It is a universal power generation technology in the world. Wind turbine blade is the key part of wind turbine, its quality reliability and performance directly affect the operation of the whole unit. Many medium and large wind turbine blades are made of fiberglass skin, but the surface cracks, delamination and other defects will inevitably occur in the long-term use. Once such defects occur, they will cause extremely serious consequences. Therefore, it is very important to conduct regular inspection of the blades.

Infrared thermal image technology is to obtain infrared thermal image by using infrared detector and optical imaging objective lens to receive the infrared radiation energy distribution pattern of the measured target and reflect it to the photosensitive element of infrared detector. In common words, the invisible infrared energy emitted by the object is transformed into visible thermal image. Different colors on the thermal image represent different temperatures of the measured object. Infrared thermal camera is a non - contact measurement and non - destructive testing technology.

During the operation of wind power blades, heat will be generated, and the surface temperature at cracks and delamination will be higher than the surrounding area. When infrared thermal camera is used to detect the blades, high temperature points will be shown in the thermal image, so as to locate the specific locations of cracks and delamination, which is convenient for staff to carry out timely maintenance.

Many adopt ultrasonic technology for nondestructive testing of blades. However, compared with ultrasonic technology, infrared thermal imaging technology consumes less time, has lower maintenance cost and has better detection effect. However, domestic infrared thermal imaging technology for the detection of blade deep defects still need to be improved, deep detection for nondestructive testing is a difficult point.