Evaluation of insulator aging status based on multispectral imaging optimized by hyperspectral analysis

•A combined technology of multispectral and hyperspectral imaging could evaluate the aging status of insulating materials.•The best combination of 3 narrow characteristic bands for evaluating the acid aging degree of insulators is 700 nm, 720 nm and 950 nm, with an accuracy of 83.1 m % in a lab experiment.•An aging evaluation algorithm based on multispectral image analysis could realize quantitative assessment of aging degree of insulators. Composite insulators are widely used in transmission line and power equipment due to high mechanical strength and antifouling property. However, the aging problem of composite insulator caused by the degradations of organic materials is considered as the primary cause of common insulator faults. In this paper, an efficient aging evaluation method is proposed based on multispectral and hyperspectral imaging technologies. First, the hyperspectral analysis was performed to select the primary characteristic bands in 374–970 nm. Then, using a simplified multispectral imager, the aging degree of the samples were obtained by spatial clustering of gray values of multispectral images collected by the multispectral imager. In the first and non-optimized verification experiment, an aging status detection accuracy of 83 % was achieved. The proposed method is therefore a very promising attempt to apply spectral imaging technology to power equipment evaluation, which has great potential for on-site status monitoring of insulation materials.