Abstract: PLC control system is an advanced industrial control equipment that can achieve precise control of objects and respond quickly to them. This paper aims to propose an automatic control design scheme for pneumatic solenoid valves based on the Siemens miniature PLC (S7-200). This scheme realizes precise automatic control of pneumatic solenoid valves by integrating low-voltage electrical appliances (including C6 type air circuit breakers, 220V-to-24V power supplies, terminal blocks, etc.) with Siemens PLC technology. During the design process, the STEP7-MicroWIN SMART software was used for PLC programming, and comprehensive debugging was conducted to ensure stable system operation. The system features high automation, strong reliability, and easy operation, capable of realizing timing switching and automatic adjustment of pneumatic solenoid valves. Read More

Abstract: Based on the Reynolds-averaged Navier-Stokes governing equations and the unstructured grid rotating/stationary sliding surface technology, this paper studies the aerodynamic layout and efficiency enhancement mechanism of the near-space propeller blade tip winglet configuration. First, the feasibility of the configuration is verified by comparing and analyzing different lift propeller layout schemes. Secondly, the aerodynamic layout design of the blade tip winglet propeller is studied by changing the winglet inclination angle and length parameter indicators. Finally, the ANSYS simulation analysis is used to calculate the influence of the winglet design on the propeller velocity vector distribution, blade pressure and propeller aerodynamic efficiency, and the performance influence law of the basic parameters is preliminarily established, and the overall design scheme of the new blade tip winglet propeller design is completed. The study shows that the blade tip winglet propeller layout is a reasonable and feasible technical approach to improve the aerodynamic efficiency in the near-space working environment, and it has a certain reference role in the development of new configuration propeller aircraft. Read More

Abstract: Aviation plugs are characterized by safety, reliability, waterproof and dustproof which have been widely used in various industries. Aviation plugs are currently mainly welded manually, a method with low welding efficiency and a high error rate. The identification and positioning of the welding cups of aviation plugs is a key point in the automatic technology of welding aviation plugs. This paper proposes a combined algorithm based on YOLOv5 and image processing algorithms to realize the solder cup recognition and localization of aviation plugs. In order to improve the recognition and positioning accuracy of the solder cup of the aviation plug, this paper carries out improvement and optimization on the basis of the original YOLOv5 model: One is to embed the ECA attention mechanism in the network; Second, the Wise-IOU (WIOU) loss function is used to replace the loss function of the original model. Improved YOLOv5 algorithm combined with image processing algorithms. Using algorithms to solder cup images noise reduction, gray scale binarization, Hough transform contour recognition. Finally, the feature extraction match function is used for template matching. This enables the identification and positioning of solder cups for aviation plugs. Experimental validation on a home-made dataset shows that the improved algorithm has improved accuracy in the identification of solder cups for aviation plugs, which meets the needs of aviation plugs for soldering operations. Read More

Abstract: With the gradual promotion of Engineering Education Accreditation, the reform of the "Engineering Mechanics" course in the electrical engineering major is particularly urgent. Based on the background of Engineering Education Accreditation, this paper discusses the importance of the "Engineering Mechanics" course in the electrical engineering major, analyzes the shortcomings of the course setting and the new requirements brought by Engineering Education Accreditation, and proposes four main ideas for curriculum reform: strengthening the combination of theory and practice, dynamically updating course content, optimizing the school-enterprise cooperation model and establishing a diversified evaluation mechanism. Through the analysis of specific teaching cases, the effectiveness of these reform measures is verified, and corresponding response strategies are provided for the challenges that may be faced during the implementation process to ensure the effectiveness and sustainability of teaching reform. Finally, looking to the future, the importance of continuously promoting curriculum reform is emphasized to cultivate high-quality engineering talents that better meet the needs of the industry. Read More

Abstract: Rolling bearings often operate under complex working conditions. When local faults occur in rolling bearings, their vibration signals contain not only periodic transient shock components related to fault information, but also harmonic components such as shaft rotation frequency and background noise. Therefore, bearings operate in high noise fault environments, and direct envelope demodulation analysis of rolling bearing vibration signals often yields poor results. A strong noise fault diagnosis method for rolling bearings based on EEMD-RRSD is proposed to address the above issues. This method first performs EEMD decomposition on the signal, and then reconstructs the signal based on spectral kurtosis and correlation coefficient criteria. Perform resonance sparse decomposition on the reconstructed signal, perform Hilbert demodulation analysis on the low resonance components based on the fast spectral kurtosis map, extract the characteristic frequency of bearing faults, and then diagnose rolling bearing faults. The analysis results of simulation signals and experimental signals show that this method can effectively extract the impact components in the vibration signals of bearing faults and diagnose bearing faults. Read More

Abstract: In the context of the increasingly urgent global transition in energy structure and environmental protection demands, the new energy vehicle (NEV) industry has rapidly emerged with its clean and efficient characteristics. Fast charging technology has become a crucial link in the NEV industry chain, playing a vital role in enhancing the overall performance of vehicles. This paper delves into the current development status and challenges faced by fast charging technology for power batteries in NEVs, with a particular focus on the pivotal role of thermal management technology during the rapid charging process. It provides a detailed analysis of the working principles, performance characteristics, and application environments of mainstream thermal management technologies, including air cooling, liquid cooling, phase change cooling, and heat pipe technology. Additionally, this paper examines the innovative applications of emerging technologies such as composite thermal management systems, microchannel heat pipes, and advanced materials. It points out that thermal management technology for fast charging batteries needs to overcome challenges in economy and reliability, moving towards integration and intelligence. By summarizing existing research achievements and shortcomings, this paper aims to provide theoretical support and practical guidance for the sustainable development of fast charging technology in NEVs, thereby promoting the prosperity and development of the NEV industry. Read More

Abstract: Ultra-high voltage substation plays an important role in the modern power system. It is the transmission hub of power, connecting large power plants and end users. With the continuous expansion of power grid scale and the improvement of voltage level, the safety management of ultra-high voltage substation equipment operation is particularly important. Based from the characteristics of ultra-high voltage substation, this paper will systematically study and discuss the key links of equipment operation safety management, in order to provide useful reference for improving the safe and stable operation level of China's power system. Read More

Abstract: As the core component of the modern power transmission system, the stable operation of the UHV power grid is of great significance to ensure the overall safety of the power system. As a key line of defense in the ultra-high voltage power grid, relay protection can detect and isolate faults in time, thus limiting the impact of the accident to the minimum range. Setting calculation is an important basis for relay protection, which involves a series of complex calculation and analysis processes. This paper deeply analyzes the key technology of ultra high voltage power grid relay protection setting calculation, discusses the specific factors of the substation configuration on the setting calculation, carefully analyzes the principles of the setting calculation, comprehensively analyzes the related protection device configuration strategy, and further study the potential problems existing in the setting calculation and its effective countermeasures. Through the in-depth discussion and research of these key technical problems, it provides a set of scientific and reasonable norms and guidance methods for the relevant personnel in the setting and calculation of the relay protection of the ultra-high voltage power grid, so as to effectively guarantee the long-term stable operation and safe power supply of the power system. Read More