Zheng Han

Electrical contact is a critical phenomenon, and the contact state of the contacts directly determines the stability of system operation. Traditional methods of analyzing contact performance by disassembling components suffer from structural damage and limitations in accuracy. This paper proposes a non-destructive analysis method for contact regions based on computed tomography (CT) technology. Taking relay contacts as the subject of study, the method reconstructs three-dimensional digital models through CT scanning and establishes a voxel-based visualization of the microscopic contact system based on differences in material electron density. Furthermore, an adaptive surface-voxel dual-domain mapping coupling method is proposed to obtain a set of candidate points in the proximity region, and a Gaussian mixture model is utilized to determine segmentation thresholds. Finally, by combining a statistically driven mechanism for region selection and fusion precise extraction and quantitative characterization of the contact region are achieved. The results indicate that the obtained contact projection area shows a significant correlation with contact resistance, providing non-destructive and efficient technical support for the analysis of contact state evolution and full-lifecycle health management.

Testing methods for contact arc erosion resistance are closely linked to design processes that enhance contact lifespan. Traditional electrical contact simulation testing systems suffer from lengthy testing cycles, prompting the adoption of laser ablation technology as a rapid testing method for contact erosion resistance. This paper establishes a two-dimensional heat-flow coupled model to analyze the evolution of ablation pits under time-varying laser spot patterns. Subsequently, experiments employed a time-varying spot strategy to modulate laser parameters during the ablation of copper specimens. The dynamic evolution of ablation morphology, volume loss, and ablation depth was analyzed, revealing the time-dependent thermal effects on the material. This work provides optimization insights for subsequent laser-based simulation methods of electrical damage testing on contact surfaces.

At the microscale, the three-dimensional morphological features of contact surfaces have a significant impact on the performance of electrical contacts. This paper aims to reconstruct the microscopic contact state of contact groups and to deeply study the effect of contact morphological features on electrical contact performance. To fully obtain multimodal data such as the three-dimensional micro-morphological features and chemical composition distribution of contact surfaces, this paper proposes a contact surface feature-matching method based on entropy rate superpixel seed point adaptive morphological reconstruction. This method can adaptively retain meaningful seed points while filtering out invalid seed points, effectively solving the problem of over-segmentation in traditional superpixel segmentation method. Experimental results show that the proposed method achieves a segmentation accuracy of 92% and reduces over-segmentation by 30% compared to traditional methods. Subsequently, on the basis of the moving and static contact group difference plane model and the W-M model, this paper constructs a three-dimensional surface fractal contact model with an irregular base. This model has the ability to layer simulate multi-parameter elastic and plastic and to extract fractal parameter point cloud height, which can more accurately reflect the actual contact state of the contact group. The model demonstrates a 15% improvement in contact area prediction accuracy and a 20% reduction in contact resistance estimation error compared to existing models. Finally, this paper compares and verifies the theoretical feasibility of the model, providing a new theoretical contact model for the study of the impact of three-dimensional micro-morphology on the electrical contact reliability.

In order to restore the microscopic contact of the real contact surface, this paper uses non-contact three-dimensional topography equipment to obtain images and topography data of the microscopic surface of the contact. According to the similarity of the contact characteristics between the movable and stationary contact surfaces, global features of the erosion area and local phase consistency feature points are extracted for rough matching and fine matching respectively. Based on the matching of contact images, the topography data is transformed to restore the contact position of the contacts. Based on the real contact surface data, combined with the contact difference plane model, it provides a new approach for analyzing the process of contact spot changes.