As aerospace, electrified railway, weapon equipment manufacturing, and other fields have leapt forward, the operating environment of current-carrying friction pairs is becoming increasingly severe, and research on the current-carrying friction and wear theory and its vital technologies are progressively in demand. This study summarizes the relevant research on the current-carrying friction and wear. In this study, the essential characteristics and classification of current-carrying friction and wear are summarized, the effect of working parameters on current-carrying friction and wear performance is clarified, and the generation mechanism, failure mechanism, and factors of current-carrying friction and wear are emphatically investigated. Moreover, the mechanism of arc generation and the effect of environmental conditions and surface facial masks on the friction and wear process are summarized. This paper also introduces the preparation technology of a conductive wear-resistant self-lubricating material, the main factors affecting the conductive wear-resistant property of the coating, and the action mechanism. The simulation and prediction results of the current-carrying friction and wear temperature field and the wear amount are presented. Finally, the problems in the current-carrying friction and wear research are classified, and future research directions in this field are proposed. The future’s critical development and improvement directions are also proposed from the aspects of developing coating quality evaluation equipment, optimizing the coating quality, and studying the coating self-lubricating mechanisms.

As one of the most effective methods to detect the partial discharge (PD) of transformers, high frequency PD detection has been widely used. However, this method also has a bottleneck problem; the biggest problem is the mixed pulse interference under the fixed length sampling. Therefore, this paper focuses on the study of a new pulse segmentation technology, which can separate the partial discharge pulse from the sampling signal containing impulse noise so as to suppress the interference of pulse noise. Based on the characteristics of the high-order-cumulant variation at the rising edge of the pulse signal, a method for judging the starting and ending time of the pulse based on the high-order-cumulant is designed, which can accurately extract the partial discharge pulse from the original data. Simulation results show that the location accuracy of the proposed method can reach 94.67% without stationary noise. The field test shows that the extraction rate of the PD analog signal can reach 79% after applying the segmentation method, which has a great improvement compared with a very low location accuracy rate of 1.65% before using the proposed method.

The three-phase composite structure is widely used in the power industry, especially for insulation systems of power equipment. As delamination defects always take place on such equipment, i.e. defects occur inside the three-phase composite structure. Therefore, this paper proposes to used the terahertz time-domain spectroscopy (THz-TDS) to detect the inner defects of the three-phase composite structure. Firstly, a three-layer reflection model of the terahertz wave is established, and a corresponding theoretical analysis of three-phase composite with insulation delamination defect is carried out. After then, an artificial sample with a delamination defect is prepared according to the actual structure of the three-phase composite. Besides, the THz-TDS analysis of the samples is carried out after tested by the THz-TDS system with the reflective mode. The experimental results show that the insulation delamination of the three-phase composite can be effectively identified by collecting the signals of the THz-TDS system. This paper theoretically and experimentally proves the feasibility of the new method based on the THz-TDS system for three-phase composite delamination nondestructive testing, which provides a new idea for inner defects detection within the three-phase composite and its condition assessment.