More accurate sizing of renewable energy sources under high levels of electric vehicle integration

Electric vehicles (EVs) and distributed generation are expected to play a major role in modern power systems. Although many studies have introduced novel models to integrate distributed generation into high levels of EV-adoption scenarios, none has considered EV-embedded battery performance degradation and its economic effect on system planning. Based on well-established models and data to emulate the capacity fading of lithium-ion batteries, the current work presents a mixed-integer linear programming optimization framework with decision variables to size renewable energy resources (RESs) in modern microgrids. The objective function aims to minimize the total cost of the system while guaranteeing a profitable operation level of vehicle-to-grid (V2G) application, narrowing the gap between design stage and real-life daily operation patterns. Stochastic modeling is used to incorporate the effect of different uncertainties involved in the issue. A case study on a residential system in Okinawa, Japan, is introduced to quantitatively illustrate how a profitable V2G operation can affect RES sizing. The results reveal that accounting for the economic operation of EVs leads to the integration of significantly higher capacities of RESs compared with a sizing model that excessively relies on V2G and does not recognize battery-fading economics.     

High gain observer for a class of nonlinear systems with coupled structure and sampled output measurements: application to a quadrotor

This paper proposes a new high gain observer for a class of non-uniformly observable nonlinear systems with coupled structure driven by sampled outputs. The considered class of systems is particularly constituted by several subsystems where each subsystem is associated to a subset of the output variables. The observer design is carried out through two steps. First, a high-gain observer is proposed in the continuous-time output case under the assumption that an adequate persistent excitation condition is satisfied by each subsystem. Then, the proposed observer is redesigned to handle the case of sampled outputs leading thereby to a continuous-discrete time observer. The latter property is achieved thanks to the approach pursued along the convergence analysis. The effectiveness of the proposed observer is emphasised in a realistic simulation framework involving a mathematical model of a quadrotor which is diffeomorphic to the proposed class of considered systems.     

Nonlinear robust control of hypersonic aircrafts with interactions between flight dynamics and propulsion systems

This paper addresses the nonlinear robust tracking controller design problem for hypersonic vehicles. This problem is challenging due to strong coupling between the aerodynamics and the propulsion system, and the uncertainties involved in the vehicle dynamics including parametric uncertainties, unmodeled model uncertainties, and external disturbances. By utilizing the feedback linearization technique, a linear tracking error system is established with prescribed references. For the linear model, a robust controller is proposed based on the signal compensation theory to guarantee that the tracking error dynamics is robustly stable. Numerical simulation results are given to show the advantages of the proposed nonlinear robust control method, compared to the robust loop-shaping control approach.     

水下湿法焊接工艺在沉船打捞工程中的应用

针对某次沉船事故打捞方案中需要在水下焊接扳正桩头的情况,设计了原桩头1/4尺寸的缩比模型,为验证水下焊接质量,在不同焊接规范下对缩比模型进行焊接,并对焊后试件的力学性能进行了检测。结果表明,在该焊接规范下所焊试件的焊缝成形良好,目测无明显缺陷,所设计试件结构的承载拉力达到了设计承载力的2倍,且焊接效率较高,能在短时间内完成施焊工作,实现了预期设计目标。     

两栖装甲车辆由陆入水过程中车体稳定性分析

对两栖装甲车辆水动力学模型的构建以及基于水上航行耐波稳定性的横摇运动进行了探索。首先建立了两栖装甲车辆由陆入水的动力学模型,并进行了仿真分析；而后将模型试验与融入遗传算法的系统辨识思想相结合,构建了对于两栖装甲车辆摇荡运动的辨别模型；最后通过对车辆在水上的横摇运动试验设计及侧体方案布置,对辨别模型的应用效果进行了验证。通过研究发现,水动力学模型能够对两栖装甲车辆由陆入水时的车体稳定性情况进行准确描述,基于遗传算法的系统辨识方法能够分段辨识两栖装甲车辆的横摇运动,为车辆水上航行稳定性的研究提供了借鉴。     

Impact of vehicle charging on Portugal's national electricity load profile in 2030

This study aims to explore the impact of light-duty passenger (LdP) electric vehicle (EV) charging on the Portuguese national load profile (LP) in 2030. The goal is to identify EV charging strategies that enable a sustainable configuration of the Portuguese LP under different potential levels of LdP EV penetration in 2030. The research offers Portuguese utilities and policymakers information regarding potential threats and solutions of different EV charging strategies on the national grid infrastructure in 2030. Furthermore, it proposes a methodology that can also be adopted in other countries to analyse similar problems. Low, medium, and high penetration scenarios were designated based on the number of LdP EVs. The low and medium penetration scenarios indicate that an intelligent grid is not necessary to perform charging activities. However, coordinating EV charging in the evening via a smart grid (SG) is imperative in the high penetration scenario, as unsustainable levels of power demand will otherwise be reached, compared with the current production and distribution capacity. Moreover, morning charging sessions must also be addressed, as they may induce new peaks of daily consumption given the significant amount of charging activity taking place within that period.     

A case study of socio-cultural and technical factors in automobile design: Discourses between designers and potential users on a new electric vehicle in Africa

Technological artifacts emerge and develop within social contexts, inextricably interconnecting technology and society. This article addresses this interconnection empirically, analyzing the implementation of an electric vehicle designed and built by students of automotive engineering at the Technical University of Munich (TUM) in Germany. The students created this vehicle to address problems of mobility for rural populations in Africa, aiming to provide local residents with better access to necessities of life such as healthcare, education, and transportation. The article examines African perceptions of and responses to the vehicle, as well as specific suggestions for future improvement. It discusses not only African reactions to the vehicle and its potential social impact on African societies, but also the concepts and ideas of the designers behind this automotive construction. It also acknowledges the ways in which the engineers based their work on assumptions about African needs rather than on substantial ethnographic research, which diminished their ability to succeed.     

融合前沿研究的液体电介质击穿教学研究

针对《高电压与绝缘技术》课程中液体电介质的教学难点，提出了融合前沿研究的液体电介质击穿教学方法。基于前沿的液体放电应用背景与先进的液体放电研究平台，形象地展示液体电介质的动态击穿过程，在教学内容、教学方法、考核方式等方面进行科教融合改进，实施“以学生为中心”理念的课程教学设计。该教学方式取得了较好的教学效果，能够为其它知识点的教学质量提升提供参考。     

台车式热处理炉控制系统的升级改造

针对中冶陕压重工设备有限公司热处理车间台车热处理炉改造自控系统方面的存在问题,对原有旧炉控制系统进行改造,改造后热处理炉设备升级、技术改进、效果显著,提高了热处理炉的性能。