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Neutral Point Clamped Asymmetric-Half-Bridge (NPC-AHB) has been proposed as one of the power converter topologies for the Switched Reluctance Machine (SRM) drive. This topology is characterized by multilevel operation and the capability to operate in fault tolerant mode, which is most indicated for use in applications that require high reliability. However, one fundamental aspect associated with fault tolerance operation is the necessity to diagnose and identify a fault in the power semiconductors of the converter. Thus, this paper proposes a new approach for the detection and diagnosis of multiple faults in the power semiconductors of this converter. The proposed approach is based on an image analysis, namely through the discrimination of the different eccentricities that will appear. This identification is done through the use of proposed normalized indexes that are developed from the entropy analysis. The proposed approach will allow discriminating multiple power semiconductors in fault, as well as between open and short circuit conditions. The performance and capability of the proposed approach will be tested using a laboratory system.

DC microgrids initiated the change of a paradigm regarding the concept about electrical distribution networks, especially in the context of the distributed generation associated with renewable energies. However, this new reality opens a new area of research, in which several aspects must be carefully studied. Indeed, the bipolar design is one of the principal dc microgrid configurations considering its characteristic wiring. Although holding many promising advantages, the bipolar dc microgrid has a tendency toward voltage and current imbalances due to the unequal distribution of the loads and generators between the two poles. Thus, specific power electronic-based solutions are required to ensure the balance of these dc microgrids. Within this frame, this article gives a comprehensive review of the multiple architectures and power electronic topologies proposed to mitigate/eliminate this undesired condition. The following provides an insightful classification and discussion with the pros and cons of these solutions. This work can serve as a timely review for researcher/engineers who want to enter the voltage balancing field in the bipolar dc grids and promote the innovation of their power electronics-enabled solutions.

Distributed energy resources (DERs), such as solar photovoltaics (PVs), are required to achieve a high performance and an efficient use of generated renewable power in grid-integrated applications, both in normal and fault operating conditions. In this article, a grid-following (GFL) multifunctional control strategy for a three-phase three-level T-type quasi-impedance source inverter (3L-T-type qZSI) is studied through simulation and experimental tests. The GFL functionality is achieved by a proportional–integral (PI)-based dq current controller for the active and the reactive power tracking. A PI-based dc controller is used for the dc-link voltage control by taking advantage of the quasi-impedance source (qZS) network ability for input voltage boosting. The dc–ac power conversion is accomplished through a space vector pulsewidth modulation (SVPWM) with inner capacitors voltages balancing capability and minimum common-mode voltage (CMV) generation. Besides, a low-voltage ride-through (LVRT) strategy was implemented to fulfill the fault requirements imposed by the Spanish standard. The simulation and experimental results demonstrate the abovementioned functionalities and validate the stability and good dynamic response of the grid-connected 3L-T-type qZSI. Thus, this work supposes a novel contribution due to the few works previously reported in the literature concerning the performance of this relatively recent inverter topology in grid-tied applications.

Le délai de reperfusion myocardique conditionne le pronostic du syndrome coronaire aigu avec sus-décalage du segment ST (SCA ST+). Depuis 2006, un appel précoce au Samu est préconisé. Pour autant, nombre de patients échappent à cette prise en charge « idéale ».

The energy sector plays a vital role in achieving social and economic development through satisfying the energy needs of the different economic sectors. However, vast majority of power stations burn fossil fuels in order to produce energy. In this way, saving energy and using it efficiently is important. So, in this paper, it will be described a mobile and web-based student learning system for rational use of energy. This system was specially developed to teach undergraduate students at School of Technology of Setúbal / Polytechnic Institute of Setúbal. This system will provide to the students a tutorial, a set of exercises with several oriented questions, interactive animations, assessment tools, a chat room and a game for evaluation purposes. To provide a better mobility, this system has a module to be used with a mobile device.

From the leaves of Ilex affinis and Ilex buxifolia, two adulterant species of “erva maté” (Ilex paraguariensis), three new triterpenoid glycosides were isolated. Affinoside 1 (3β-O-{β-d-glucopyranosyl-(1→3)-[2-O-acetyl-(1→2]}-α-l-arabinopyranosyl pomolic acid 28-O-β-d-glucopyranosyl ester, 1) was isolated from I. affinis, while buxifolioside I (28-O-β-d-glucopyranosyl ester of (20S)-3α,19α-dihydroxyurs-12-ene-23,28-dioic acid, 7) and buxifolioside II (28-O-β-d-glucopyranosyl ester of (20S)-3β,19α-dihydroxyurs-12-en-24,28-dioic acid, 8) were isolated from I. buxifolia. Along with these new compounds, ilexoside II (2), ursolic acid (3), 28-nor-ursolic acid (4), 3β-O-acetylursolic acid (5), and uvaol (6) were also isolated. The observed results confirm the structural specificity of the I. paraguariensis triterpenoids and reinforce a previous proposal to detect maté adulteration by triterpenoid analysis. In addition, the in vitro antitrypanosomal activity of some Ilex triterpenoids is also reported.

Two new saponins were isolated from the leaves of Ilex psammophila . Their structure was established by chemical and spectroscopic methods as 28- O - g - d -glucopyranosylester of 20( S )-ilexgenin A ( 4 ) and 28- O - g - d -glucopyranosylester of 20( S )-3 g ,19 f ,24-trihydroxyurs-12-ene-23, 28-dioic acid ( 5 ).

Intramuscular fat is an important meat quality trait in pig production. Previously, genetic variants of the heart fatty acid-binding protein (H-FABP) gene and the adipocyte fatty acid-binding protein (A-FABP) gene were suggested to be associated with intramuscular fat content. The objective of this investigation was to study these associations in the three most important Austrian breeding populations (Piétrain, Large White, and Landrace). Restriction fragment length polymorphism analysis of the H-FABP gene revealed a new MspI polymorphic site and genetic variation in all three breeds. Microsatellite analysis of the A-FABP locus showed up to nine different microsatellite alleles segregating. In Austrian breeds, no significant influence of the A-FABP and H-FABP gene polymorphisms on intramuscular fat could be detected. We also evaluated possible associations between the genetic variations at the H-FABP and A-FABP loci and other growth and carcass traits (average daily gain, feed conversion ratio, lean meat content, pH values, meat color, and drip loss). With regard to the extent of the effects, these genetic markers cannot be recommended for selection on growth and carcass traits in Austrian breeding populations.

A pulse width rectifier referred to as a half-bridge single-phase buck-boost type AC–DC converter is proposed. The efficiency of the circuit is higher than that presented by other converters of this type, as only one reverse blocking power semiconductor conducts at any time. A comparative study between the new converter and a converter with four switching devices is carried out. The control strategies for the output DC voltage and input AC current are also presented and discussed. To achieve sinusoidal input current and high power factor, sliding-mode control of the input current is proposed. This nonlinear control strategy, applied to this single-phase step-up/down type AC–DC converter, also reduces the size, weight and cost of the DC inductor. Given the comparatively slow dynamics of the DC output voltage, a proportional integral (PI) controller is adopted to regulate the converter output voltage. Simulation and experimental results show the improved efficiency, high power factor and low harmonic distortion characteristics of the circuit.

•The target of this research is an unbalanced LV distribution grid with storage and massive penetration of PV microgeneration.•We use an unbalanced three-phase power flow algorithm.•We propose to control an Energy Management System (EMS), based on a new objective function.•The EMS is based on a Multi-Objective Particle Swarm Optimization (MOPSO) algorithm.•We seek at optimizing Voltage Unbalance Factor (VUF), voltage deviation, power losses and PV curtailment.

•The use of storage systems in distribution networks.•A multi-objective optimization approach for the location and sizing of storage systems is proposed.•Consideration of the converters associated to the storage system to supply an ancillary service.•The math model incorporates the conflicting nature of the objectives and the discrete nature of the decision variables.•A new post-Pareto analysis that is based on the sum of the ranking differences.