The electric vehicle in smart homes: a review and future perspectives

The electric mobility dissemination is forcing the adoption of new technologies and operation paradigms, not only focusing on smart grids, but also on smart homes. In fact, the emerging technologies for smart homes are also altering the conventional grids toward smart grids. By combining the key pillars of electric mobility and smart homes, this paper characterizes the paradigms of the electric vehicle (EV) in smart homes, presenting a review about the state of the art and establishing a relation with future perspectives. Since the smart home must be prepared to deal with the necessities of the EV, the analysis of both on board and off board battery charging systems are considered in the paper. Moreover, the in-clusion of renewable energy sources, energy storage systems, and dc electrical appliances in smart homes towards sustainability is also considered in this paper, but framed in the perspective of an EV off board battery charging system. As a pertinent contribution, this paper offers future perspectives for the EV in smart homes, including the possibility of ac, dc, and hybrid smart homes. Covering all of these aspects, exemplificative and key results are presented based on numerical simulations and experimental results obtained with a proof of concept prototype.FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019. This work has been supported by the FCT Project newERA4GRIDs PTDC/EEI-EEE/30283/2017, and by the FCT Project DAIPESEV PTDC/EEI-EEE/30382/2017. Tiago Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by FC

Unified traction and battery charging systems for electric vehicles: a sustainability perspective

This paper presents an analysis of unified traction and battery charging systems for electric vehicles (EVs), both in terms of operation modes and in terms of implementation cost, when compared to dedicated solutions that perform the same operation modes. Regarding the connection of the EV battery charging system with the power grid, four operation modes are analyzed: (1) Grid–to–Vehicle (G2V); (2) Vehicle–to–Grid (V2G); (3) Vehicle–to–Home (V2H); and (4) Vehicle–for–Grid (V4G). With an EV unified system, each of these operation modes can be used in single–phase and three–phase power grids. Furthermore, a cost estimation is performed for an EV unified system and for dedicated systems that can perform the same functionalities, in order to prove the benefits of the EV unified approach. The cost estimation comprises two power levels, namely 6 kW, single–phase, related to domestic installations, and 50 kW, three–phase, related to industrial installations. The relevance of unified traction and battery charging systems for EVs is proven for single–phase and three–phase power grids.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019. This work has been supported by the FCT Project DAIPESEV PTDC/EEI-EEE/30382/2017, and by the FCT Project new ERA4GRIDs PTDC/EEI-EEE/30283/2017

The role of off-board EV battery chargers in smart homes and smart grids: operation with renewables and energy storage systems

Concerns about climate changes and environmental air pollution are leading to the adoption of new technologies for transportation, mainly based on vehicle electrification and the interaction with smart grids, and also with the introduction of renewable energy sources (RES) accompanied by energy storage systems (ESS). For these three fundamental pillars, new power electronics technologies are emerging to transform the electrical power grid, targeting a flexible and collaborative operation. As a distinctive factor, the vehicle electrification has stimulated the presence of new technologies in terms of power management, both for smart homes and smart grids. As the title indicates, this book chapter focuses on the role of off-board EV battery chargers in terms of operation modes and contextualization for smart homes and smart grids in terms of opportunities. Based on a review of on-board and off-board EV battery charging systems (EV-BCS), this chapter focus on the off-board EV-BCS framed with RES and ESS as a dominant system in future smart homes. Contextualizing these aspects, three distinct cases are considered: (1) An ac smart home using separate power converters, according to the considered technologies; (2) A hybrid ac and dc smart home with an off-board EV-BCS interfacing RES and ESS, and with the electrical appliances plugged-in to the ac power grid; (3) A dc smart home using a unified 2 off-board EV-BCS with a single interface for the electrical power grid, and with multiple dc interfaces (RES, ESS, and electrical appliances). The results for each case are obtained in terms of efficiency and power quality, demonstrating that the off-board EV-BCS, as a unified structure for smart homes, presents better results. Besides, the off-board EV-BCS can also be used as an important asset for the smart grid, even when the EV is not plugged-in at the smart home.(undefined

Frequency of LCT -13910C>T single nucleotide polymorphism associated with adult-type hypolactasia/lactase persistence among Brazilians of different ethnic groups

<p>Abstract</p> <p>Background</p> <p>Adult-type hypolactasia, the physiological decline of lactase some time after weaning, was previously associated with the LCT -13910C>T polymorphism worldwide except in Africa. Lactase non-persistence is the most common phenotype in humans, except in northwestern Europe with its long history of pastoralism and milking. We had previously shown association of LCT -13910C>T polymorphism with adult-type hypolactasia in Brazilians; thus, we assessed its frequency among different Brazilian ethnic groups.</p> <p>Methods</p> <p>We investigated the ethnicity-related frequency of this polymorphism in 567 Brazilians [mean age, 42.1 ± 16.8 years; 157 (27.7%) men]; 399 (70.4%) White, 50 (8.8%) Black, 65 (11.5%) Brown, and 53 (9.3%) Japanese-Brazilian. DNA was extracted from leukocytes; LCT -13910C>T polymorphism was analyzed by PCR-restriction fragment length polymorphism.</p> <p>Results</p> <p>Prevalence of the CC genotype associated with hypolactasia was similar (57%) among White and Brown groups; however, prevalence was higher among Blacks (80%) and those of Japanese descent (100%). Only 2 (4%) Blacks had TT genotype, and 8 (16%) had the CT genotype. Assuming an association between CC genotype and hypolactasia, and CT and TT genotypes with lactase persistence, 356 (62.8%) individuals had hypolactasia and 211 (37.2%) had lactase persistence. The White and Brown groups had the same hypolactasia prevalence (~57%); nevertheless, was 80% among Black individuals and 100% among Japanese-Brazilians (<it>P </it>< 0.01).</p> <p>Conclusion</p> <p>The lactase persistence allele, LCT -13910T, was found in about 43% of both White and Brown and 20% of the Black Brazilians, but was absent among all Japanese Brazilians studied.</p

A penalty approach to a discretized double obstacle problem with derivative constraints

This work presents a penalty approach to a nonlinear optimization problem with linear box constraints arising from the discretization of an infinite-dimensional differential obstacle problem with bound constraints on derivatives. In this approach, we first propose a penalty equation approximating the mixed nonlinear complementarity problem representing the Karush-Kuhn-Tucker conditions of the optimization problem. We then show that the solution to the penalty equation converges to that of the complementarity problem with an exponential convergence rate depending on the parameters used in the equation. Numerical experiments, carried out on a non-trivial test problem to verify the theoretical finding, show that the computed rates of convergence match the theoretical ones well

Portable lactate analyzer for measuring lactate in cerebrospinal fluid (CSF) and plasma ? method-comparison evaluations

Increased plasma lactate levels can indicate the presence of metabolic disorders in HIV infected individuals. Objective: To determine whether a portable analyzer is valid for measuring cerebrospinal fluid (CSF) and plasma lactate levels in HIV infected individuals. Method: CSF and plasma were collected from 178 subjects. Samples tested by the Accutrend® portable analyzer were compared to those tested by a reference device (SYNCHRON LX® 20). Results: The portable analyzer had in plasma sensitivity of 0.95 and specificity 0.87. For CSF the specificity was 0.95; the sensitivity 0.33; the negative predictive value was 95% and the positive predictive value 33%. Conclusions: These findings support the validity of the portable analyzer in measuring lactate concentrations in CSF that fall within the normal range. The relatively poor positive predictive value indicates that a result above the reference range may represent a “false positive test”, and should be confirmed by the reference device before concluding abnormality