In this study, a method for testing the aging of silicone rubber insulators using terahertz waves in the 0.17–0.22 THz frequency band is proposed, aiming at the problem of online non-destructive testing of the aging degree of composite insulators. The relationship between the aging degree of silicone rubber composite insulators and the relative dielectric constant was studied through first-principles calculations and molecular chain scission models. In addition, the electromagnetic model of the terahertz signal incident on the silicon rubber sheet was simulated and the relationship between the aging degree of the silicon rubber and the terahertz input return loss was obtained. Eleven insulator samples with different degrees of aging were selected. In these samples, the degree of aging was calibrated according to the degree of surface deterioration and the average partial discharge voltage. The terahertz return loss measurement experiment was performed after that. Finally, the results of experiment and calculation simulation were compared and the reliability of the relationship between the aging degree of the silicone rubber insulator and the terahertz input return loss was verified.

Aiming at the problem that the coordinates of the existing fault point detection methods are inaccurate when determining the specific location of the fault point, this paper introduces the fault tree to design and study the over-current fault point detection method of the transmission cable ring network. For the normal and abnormal operating states of the transmission cable, determine the transmission cable's farthest over-current signal flip point fault string. The fault tree is introduced, and the over-current fault of the transmission cable ring network is substituted into the fault tree structure to realize the specific description of its characteristics; Finally, the particular location of the fault point is determined by rough measurement and precise measurement, and it is imported into the standard coordinates to realize the fault point detection. Compared with other detection methods, the positioning results obtained by the new detection method are more realistic, the detection accuracy is higher, and the specific location of the fault can be accurately found.

In view of the time-consuming and labor-intensive problems of traditional contact electroscopes, this paper designs a hardware system of non-contact voltage detector based on STM32 single-chip microcomputer. The hardware design mainly includes signal amplification and conditioning circuit and power module, Wireless transceiver module, display and alarm module, etc. In order to reduce the distortion of electric field caused by human during measurement, a wireless transceiver module device is adopted, which has a simple structure and can meet the engineering requirements of the non-contact power inspection of the transmission line.

Object detection is a classical research problem in computer vision, and it is widely used in the automatic monitoring field of various production safety. However, current object detection techniques often suffer low detection accuracy when an image has a complex background. To solve this problem, this paper proposes a double U-shaped multireinforced unit structure network (DUMRN). The proposed network consists of a detection module (DM), a reinforced module (RM), and a salient loss function (SLF). Extensive experiments on five public datasets and a practical application dataset are conducted and compared against nine state-of-the-art methods. The experiment results show the superiority of our method over the state of the art.

The principle of detecting the vacuum degree of terahertz wave is discussed. The imaging principle, imaging characteristics, imaging speed, and price of pulsed terahertz and continuous wave terahertz are compared and analyzed. The conclusion shows that the pulse terahertz frequency is higher in the practicality of vacuum detection, but it is expensive, bulky and inconvenient to operate in the field. Continuous wave terahertz imaging has high frequency resolution, low price, short imaging time and practical more sexual.