Energy Management Strategy of Hybrid Energy Storage System Based on Road Slope Information

To maximize the performance of power batteries and supercapacitors in a hybrid energy storage system (HESS) and to resolve the conflict between the high power demands of electric vehicles and the limitations of high-current charging and discharging of the power battery, a vehicle power demand model incorporating road slope information has been constructed. This paper takes a HESS composed of power battery and supercapacitor as the object, and a rule-based energy management strategy (EMS) based on road slope information is proposed to realize the reasonable distribution and management of energy under the slope condition. According to the slope information of the road ahead, the energy consumption in the next period was predicted, and the supercapacitor is charged and discharged in advance to meet the energy demand of uphill and the energy recovery capacity of downhill to avoid the high current charge and discharge of the battery. Subsequently, the improved EMS performance was simulated under the New York City Cycle (NYCC) driving conditions with additional slope driving conditions. The simulated results indicate that compared to the existing EMS, the proposed EMS based on slope information can effectively distribute the power demand between the power battery and the supercapacitor, can reduce the discharge current and the duration of high-power discharge, and has a 20.4% higher energy recovery efficiency, effectively increasing the cruising range

Surface Charge Dissipation Characteristics of Al₂O₃/Silicone Rubber Composites With Different Weight Percentages

To identify a nanocomposite material capable of mitigating surface charge accumulation issues in silicone rubber composite insulators, this paper investigated the surface charge dissipation characteristics of micron-sized Al2O3/silicone rubber composites with different weight percentages under positive dc voltage. Furthermore, this paper investigated the influence of the uncharged and charged silicone rubber on the surface flashover voltage under positive dc voltage. The result show that the addition of micron-sized Al2O3 particles effectively ameliorates the severity of surface charge accumulation. In comparison to pure silicone rubber, the reduction in maximum surface charge density and average surface charge density of different weight percentage Al2O3/silicone rubber composites ranges from 18.60% to 50.60% and from 33.26% to 57.53%, respectively. When there is no surface charge on the silicone rubber surface, the addition of micron-sized Al2O3 particles at different weight percentages results in a decrease in positive dc surface flashover voltage. Conversely, when a positive surface charge is applied to the silicone rubber surface, the greatest reduction in positive dc surface flashover voltage occurs in pure silicone rubber. Furthermore, the positive DC flashover voltage of pure silicone rubber can recover to 86.53% of its value without applied surface charge at a decay time of 60 minutes. In contrast, the addition of micron-sized Al2O3 particles at different weight percentages diminishes the impact of surface charge on the surface flashover voltage, allowing it to recover to 92.03% to 94.18% of its value without applied surface charge

The Development History and Current Situation of General Practice Education in Guangdong Province in the Past 30 Years

With the strong support of national and local policies, the construction of general practice education system and personnel training have been developed in Guangdong Province for nearly 30 years. Since 1996, general practice education in Guangdong Province has gone through four stages, including exploration and start, vigorous growth, development and perfection, comprehensive development. Colleges and universities in Guangdong Province, represented by Guangzhou Medical University, have explored and established a multi-level, multi-path, multi-form and multi-objective general practice education system of treatment-prevention integration, with interconnected academy education, job-transfer training, standardized training, postgraduate education and continuing education, and a standardized training model of general practitioners based on "5+3" has been basically established. The pass rate of the provincial training certificate examination of general practice training students has reached more than 85%. In 2020, there were 4 general practitioners per 10 000 residents, meeting the national requirement of 3 general practitioners per 10 000 residents in 2020. With the purpose to analyze the current situation of the development of general practice education in Guangdong Province, this paper comprehensively summarized the experience and lessons of discipline construction and education training of general practice, broadened the paths and modes of the quality of general practice personnel training, put forward relevant suggestions, to provide policy ideas and reference basis for the rapid development of general practice education in Guangdong Province and even in China in the future