Anibal T. de Almeida

Bio: Anibal T. de Almeida is an academic researcher from University of Coimbra. The author has contributed to research in topics: Electric motor & Efficient energy use. The author has an hindex of 38, co-authored 212 publications receiving 5616 citations. Previous affiliations of Anibal T. de Almeida include University of California, Berkeley & Beijing Jiaotong University.

Beyond induction motors — Technology trends to move up efficiency

Abstract: Premium (IEC IE3 Class) efficiency Motors are now mandatory in North America. Super-Premium (IEC IE4 Class) and IE5 Ultra-Premium efficiency classes are defined in the second edition of Standard IEC 60034-30. For line-start fixed-speed applications, Super-Premium IE4-Class Line-Start Permanent-Magnet Motors and Squirrel-Cage Induction Motors are recent entrances in the industrial motor market. For variable-speed applications, IE4-Class Variable-Reluctance Synchronous Motors are also a recent entrance in the market. For the low power range, moving from IE4 to IE5 class, may require moving away from radial-flux induction motor technology, into to the permanent magnet and reluctance technology, either using Rare-Earth or Ferrite magnets. In this paper, efficiency analysis on the best available electric motors and emerging motor technologies, such as axial-flux permanent-magnet synchronous motors, is presented. The potential efficiency gain associated with several design options as well as a study on the theoretical efficiency limit achievable taking into account those existing design options are described.

A sustainability assessment of electric vehicles as a personal mobility system

Abstract: This paper presents a study of the economic and environmental balances for Electric Vehicles (EVs) versus Internal Combustion Engine Vehicle (ICEV). The analyses were based on the Well-to-Wheel (WTW) methodology, a specific type of Life Cycle Assessment (LCA). WTW balances were carried out taking into account different scenarios for the primary energy supply and different vehicle technologies. The primary energy supply includes non-renewable sources (fossil fuels and nuclear) and Renewable Energy Source (RES). Vehicle technologies include Battery Electric Vehicle (BEV), Hybrid Electric Vehicle (HEV) and Plug-in Hybrid Electric Vehicle (PHEV). The generation scenarios considered in the study include the present European Union (EU) average mix and a planned increasing contribution from RESs. For the BEV, several real world driving cycle scenarios were investigated, using a custom built data acquisition system, in order to characterize the main factors that contribute to the overall energy consumption, associated cost and emissions. In terms of environmental impact, for the average EU electricity mix, BEVs have less than a half of the emissions than an ICEV. However, the ownership costs during its life cycle (about 10 y) are similar to an equivalent ICEV, despite the lower operational costs for BEVs. The likely battery price reduction, leading to a lower investment cost, will gradually tip the balance in favour of EVs.

Impact of the electricity mix and use profile in the life-cycle assessment of electric vehicles

Abstract: This paper presents an environmental and an economic Life-Cycle Assessment (LCA) for conventional and electric vehicle technologies, focusing mainly on the primary energy source and the vehicle operation phase Greenhouse Gas (GHG) emissions. A detailed analysis of the electricity mix was performed, based on the contribution of each type of primary energy source and their variation along a year. Three mixes were considered, with different life cycle GHG intensity: one mainly based in fossil sources, a second one with a large contribution from nuclear and a third one with a significant share of renewable energy sources. The conventional vehicle technology is represented by gasoline and diesel International Combustion Engine Vehicles (ICEVs), while the electric technology is represented by Plug-in Hybrid Electric Vehicles (PHEVs) and Battery Electric Vehicles (BEVs). Real world tests were performed for representative compact and sub-compact EVs. The use profile of the vehicle was based on data acquired by a real time data acquisition system installed in the vehicles. The results show that a mix with a large contribution from Renewable Energy Sources (RESs) does not always translate directly into low GHG emissions for EVs due to the high variability of these sources. The driving profile under different scenarios was also analyzed, showing that an aggressive style can increase the energy consumption by 47%. The tests also showed that the use of climate control can increase the energy consumption between 24 and 60%. Compared with other technologies, EVs can be more sustainable from an environmental and economic perspective; however, three main factors are required: improvement of battery technology, an eco-driving attitude and an environmental friendly electricity mix.

The role of demand-side management in the grid integration of wind power

Abstract: In a scenario of large scale penetration of renewable production from wind and other intermittent resources, it is fundamental that the electric system has appropriate means to compensate the effects of the variability and randomness of the wind power availability. This concern was traditionally addressed by the promotion of wind resource studies and acting in the supply side of energy and using energy storage technologies. However, in electric system planning, other options deserve to be evaluated, namely the options related with the energy demand. The most severe problems due to the wind power intermittence happen during the peak load hours. Thus, instead of trying to replace the lost capacity due to the intermittence, other option is to act in the energy demand side, with the aim of reducing the consumption in such hours. The demand-side management technologies are an option that must be considered to reduce and manage the wind power intermittence. The present paper analyzes the possible impact of demand-side management and demand response, with the aim of enabling the integration of the growing intermittent resources in Portugal.

Characterization of the household electricity consumption in the EU, potential energy savings and specific policy recommendations

Abstract: Although significant improvements in energy efficiency have been achieved in home appliances and lighting, the electricity consumption in the European Union household has increased by 2% per year during the past 10 years. Some reasons are associated with an increased degree of basic comfort and level of amenities and with the widespread utilisation of new types of loads. Wishing to increase the understanding of the energy consumption in the EU households for the different types of equipment including the consumers’ behaviour and comfort levels, and to identify demand trends, an energy monitoring campaign, was carried out in 12 geographically representative EU countries, accompanied by a lifestyle survey. From the measurements carried out it was concluded that Information Technologies and entertainment loads are key contributors to the power demand. In basically all types of loads there is wide range of performance levels in the models available in the market. Available technology, associated with responsible consumer behaviour, can reduce wasteful consumption. Based on a bottom up approach the European residential sector potential electricity savings that can be implemented by existing technologies and improved behaviour can reach 48%. The paper presents policy recommendations promoting market transformation and behavioural changes in the equipment selection and operation.

Past, Present, and Future of Simultaneous Localization and Mapping: Toward the Robust-Perception Age

Abstract: Simultaneous localization and mapping (SLAM) consists in the concurrent construction of a model of the environment (the map ), and the estimation of the state of the robot moving within it. The SLAM community has made astonishing progress over the last 30 years, enabling large-scale real-world applications and witnessing a steady transition of this technology to industry. We survey the current state of SLAM and consider future directions. We start by presenting what is now the de-facto standard formulation for SLAM. We then review related work, covering a broad set of topics including robustness and scalability in long-term mapping, metric and semantic representations for mapping, theoretical performance guarantees, active SLAM and exploration, and other new frontiers. This paper simultaneously serves as a position paper and tutorial to those who are users of SLAM. By looking at the published research with a critical eye, we delineate open challenges and new research issues, that still deserve careful scientific investigation. The paper also contains the authors’ take on two questions that often animate discussions during robotics conferences: Do robots need SLAM? and Is SLAM solved?

Past, Present, and Future of Simultaneous Localization And Mapping: Towards the Robust-Perception Age

Abstract: Simultaneous Localization and Mapping (SLAM)consists in the concurrent construction of a model of the environment (the map), and the estimation of the state of the robot moving within it. The SLAM community has made astonishing progress over the last 30 years, enabling large-scale real-world applications, and witnessing a steady transition of this technology to industry. We survey the current state of SLAM. We start by presenting what is now the de-facto standard formulation for SLAM. We then review related work, covering a broad set of topics including robustness and scalability in long-term mapping, metric and semantic representations for mapping, theoretical performance guarantees, active SLAM and exploration, and other new frontiers. This paper simultaneously serves as a position paper and tutorial to those who are users of SLAM. By looking at the published research with a critical eye, we delineate open challenges and new research issues, that still deserve careful scientific investigation. The paper also contains the authors' take on two questions that often animate discussions during robotics conferences: Do robots need SLAM? and Is SLAM solved?

Optimization methods applied to renewable and sustainable energy: A review

Abstract: Energy is a vital input for social and economic development. As a result of the generalization of agricultural, industrial and domestic activities the demand for energy has increased remarkably, especially in emergent countries. This has meant rapid grower in the level of greenhouse gas emissions and the increase in fuel prices, which are the main driving forces behind efforts to utilize renewable energy sources more effectively, i.e. energy which comes from natural resources and is also naturally replenished. Despite the obvious advantages of renewable energy, it presents important drawbacks, such as the discontinuity of generation, as most renewable energy resources depend on the climate, which is why their use requires complex design, planning and control optimization methods. Fortunately, the continuous advances in computer hardware and software are allowing researchers to deal with these optimization problems using computational resources, as can be seen in the large number of optimization methods that have been applied to the renewable and sustainable energy field. This paper presents a review of the current state of the art in computational optimization methods applied to renewable and sustainable energy, offering a clear vision of the latest research advances in this field.

Feedback on household electricity consumption: a tool for saving energy?

Abstract: Improved feedback on electricity consumption may provide a tool for customers to better control their consumption and ultimately save energy. This paper asks which kind of feedback is most successful. For this purpose, a psychological model is presented that illustrates how and why feedback works. Relevant features of feedback are identified that may determine its effectiveness: frequency, duration, content, breakdown, medium and way of presentation, comparisons, and combination with other instruments. The paper continues with an analysis of international experience in order to find empirical evidence for which kinds of feedback work best. In spite of considerable data restraints and research gaps, there is some indication that the most successful feedback combines the following features: it is given frequently and over a long time, provides an appliance-specific breakdown, is presented in a clear and appealing way, and uses computerized and interactive tools.