Pulsewidth modulations for the comprehensive capacitor voltage balance of n-level three-leg diode-clamped converters

In the previous literature, the introduction of the virtual-space-vector (VV) concept for the three-level, three-leg neutral-point-clamped converter has led to the definition of pulsewidth modulation (PWM) strategies, guaranteeing a dc-link capacitor voltage balance in every switching cycle under any type of load, with the only requirement being that the addition of the three phase currents equals zero. This paper presents the definition of the VVs for the general case of an n-level converter, suggests guidelines for designing VV PWM strategies, and provides the expressions of the leg duty-ratio waveforms corresponding to this family of PWMs for an easy implementation.Modulations defined upon these vectors enable the use of diode-clamped topologies with passive front-ends. The performance of these converters operated with the proposed PWMs is compared to the performance of alternative designs through analysis, simulation, and experiments.Postprint (published version

A regenerative active clamp circuit for DC/AC converters with high-frequency isolation in photovoltaic systems

DC/AC converters with high-frequency isolation and bidirectional power flow are extensively used in photovoltaic power systems and small isolated power converters at low and medium power ranges. The main disadvantages of these circuits are: high freewheeling loss of the primary leakage current, limited ZVS range for the lagging leg switches, the effects of the parasitic elements of the systems and others. To avoid these losses an energy recovery circuit based on an active voltage clamper is presented. The control circuit is designed having a number of soft switching transitions. The system has been verified by simulation and a prototype is being tested. In this paper we present an energy recovery system and a modulation sequence for the cycloconverter. The energy recovery system is based on an active voltage clamper; the voltage peaks energy is returned to the source. Furthermore, the presented modulation sequence is designed to have a maximum number of soft-switching transitions independent of the electric variables; which means minimum losses and independence on measurement systems limitations for modulation.Peer ReviewedPostprint (published version

Offensive and defensive team performance: relation to successful and unsuccessful participation in the 2010 Soccer World Cup

The present study was conducted to analyze the impact of selected offensive and defensive performance indicators in relation to teams’ success in the 2010 soccer World Cup. The sample used corresponded to 54 matches played in both the group and knockout stage. The game-related statistics gathered were: total shots, shots on goal, shots off goal, % of shots on goal from total shots, % of shots off goal from total shots, offensive and defensive effectiveness 1 (goals/total shots), and offensive and defensive effectiveness 2 (goals/shots on goal). In addition, the first’s goal influence in the match’s outcome (for the team scoring the goal: win, draw, lose) was also investigated. The results showed that, during the group stage, successful teams had better values (P <0.05) in all offensive and defensive performance indicators, with the exception of shots off goal for and shots off goal against, respectively, than unsuccessful teams. In the knockout stage, successful teams were able to maintain the same offensive performance that in the group stage while most defensive performance indicators, with the exception of shots off goal against (P=0.80), tended (P<0.2) to worsen. During the group stage, the team scoring the first goal had 66.7% of victories, 4.2% of defeats and 29.2% of draws (P<0.001). In the knockout stage, the first goal effect had a stronger influence in game’s outcome than in the group stage (P<0.01) since in 81.3% of the cases the team scoring first won the match, versus 6.3% of defeats and 12.5% of draws. Thus, offensive variables related to shots on goal and goal effectiveness appear to be better indicators of team’s success in the last World Cup than defensive variables. This information has directly implications for coaches, providing relevant feedback to plan finishing (goal scoring) practices

Three-level three-phase neutral-point-clamped back-to-back converter applied to a wind emulator

This paper presents a three-level three- phase neutral-point-clamped back-to-back converter applied to a wind emulator, where a wind power generator is connected to the grid through the back-to-back converter. The converter regulates the power extracted from the generator and controls how this power is injected to the grid with the desired power factor. Two phase locked loops are in charge of synchronizing the generator-side and the grid-side converters, regardless of the rotor speed of the generator. DC-link neutral point voltage balance is performed by the modulation strategy of the backto- back converter. Simulation and experimental results are provided to verify the correct performance of the system.Postprint (published version

2 transistors + 2 diodes-based PEBB designed for general applications in power electronics

This paper presents a new Power Electronic Building Block (PEBB) designed to facilitate the implementation of different power converter topologies. The proposed PEBB consists of two diodes and two transistors and it can be used to implement the most relevant power converter topologies, due to its modularity. The addition of the two diodes is an exclusive feature of the new PEBB, which permits to implement neutral point clamped (NPC) multilevel converters. The application of the PEBB to build a three-level NPC converter and a dc-dc push-pull converter is presented and detailed in the paper, and demonstrate that the presented PEBB can be useful to shorten converter development times.Peer ReviewedPostprint (published version

Rendimiento en el rendimiento entre equipos exitosos y no exitosos durante las copas del mundo de futbol de la FIFA 2010 y 2014

El objetivo principal de la tesis fue el de analizar las diferencias entre equipos exitosos y no exitosos durante las dos últimas Copas del Mundo (2010 y 2014), para ello planteamos 3 objetivos específicos que nos permitieran esclarecer este problema. En esa línea específicamente tratamos de determinar las diferencias en: • La eficacia ofensiva y defensiva de los equipos (objetivo específico 1). • Los patrones de distribución temporal de los goles, el efecto del primer gol marcado (objetivo específico 2). • La posesión del balón, los pases y la eficacia de los mismos (objetivo específico 3). Muestra: La muestra fue extraída de los partidos de la fase final de las Copas del Mundo de Sudáfrica 2010 y Brasil 2014. Cada Copa del Mundo constó de 64 partidos, 48 en la fase de grupos y 16 partidos en las eliminatorias. Cada equipo jugó entre 3 y 7 partidos. Estudio y comparativa entre Equipos Exitosos Y No Exitosos 112 partidos (87,5% del total de partidos) fueron seleccionados para el análisis. Los datos recogidos fueron descargados de la página oficial de la FIFA y son de dominio público. Procedimiento: La calidad de los equipos se dividió en dos categorías: Equipos Exitosos (semifinales) Equipos No Exitosos (equipos que no consiguieron pasar a la fase de grupos. Aportaciones científicas: Estudio 1: Análisis de las acciones de Finalización. Comparación de la Fase de Grupos vs Eliminatorias y la inclusión análisis de Rendimiento Defensivo. Los equipos disminuyeron de forma sustancial su potencial ofensivo durante las eliminatorias. Diferencia de mayor magnitud fue los goles a favor, aprox. - 0,5 goles por partido En general el rendimiento defensivo empeoró más que lo hizo el rendimiento ofensivo en la fase de eliminatorias. Estudio 2: Distribución temporal de goles marcados y Efecto del primer gol marcado. Comparar a los Equipos Exitosos con los No Exitosos. No Exitosos marcaban con mayor frecuencia sus goles durante la segundas partes El efecto del primer gol marcado es mayor en los Equipos Exitosos Estudio 3: Posesión y Pases. Aportación científica: Relacionar la Posesión con la variable Espacio y la Efectividad Ofensiva y Defensiva. La relación entre los minutos de posesión en el tercio ofensivo y los tiros totales (Eficacia Ofensiva 1) realizados fue similar entre los dos grupos. Equipos Exitosos tiraron a portería con mayor frecuencia (una media de 1 tiro por 1,3 minutos de posesión en el tercio ofensivo) No Exitosos, 1 tiro por cada 1,9 minutos de posesión en el tercio ofensivo

High-Level Tactical Performance Analysis with SportSense

Team sports like football have become an important economic factor. As a result, the pressure on coaches to succeed is increasing and, as a consequence, so are the expectations of the performance analysts who support the coaches in their work. Until now, performance analysis has been a mostly manual and time-consuming activity, mainly consisting of video analysis. Only since the advent of new analysis tools, these analysts have experienced support for their work. However, most existing tools are mostly limited to simple analyzes and do not support complex tactical patterns. In this paper, we present how the existing portSense system has been extended by support for dedicated tactical patterns, especially phases, continuous states, and profiles. SportSense has already been a powerful tool to assist performance analysts in running quantitative and qualitative analyzes. The tactical patterns that have been added even better support analysts in their complex tasks, which is shown in the user studies we have conducted

Pulsewidth modulations for the comprehensive capacitor voltage balance of diode-clamped multilevel converters

In the previous literature, the introduction of the virtual space vector concept for the three-level three-leg neutral-point-clamped converter has led to the definition of pulsewidth modulation (PWM) strategies guaranteeing the dc-link capacitor voltage balance under any type of load, with the only requirement being that the addition of the three phase currents equals zero. This paper presents the definition of the virtual space vectors for the general case of an n-level converter, suggests guidelines for designing virtual-space-vector PWM strategies, and provides the expressions of the phase duty-ratio waveforms corresponding to this family of PWMs. Modulations defined upon these vectors enable the use of diode-clamped topologies with passive front-ends. The performance of these converters operated with the proposed PWMs is compared to the performance of alternative designs through analysis,simulation and experiments.Postprint (published version

A statistical model for locating regulatory regions in novel DNA sequences

Available from British Library Document Supply Centre-DSC:DXN048248 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Pulsewidth modulations for the comprehensive capacitor voltage balance of diode-clamped multilevel converters

In the previous literature, the introduction of the virtual space vector concept for the three-level three-leg neutral-point-clamped converter has led to the definition of pulsewidth modulation (PWM) strategies guaranteeing the dc-link capacitor voltage balance under any type of load, with the only requirement being that the addition of the three phase currents equals zero. This paper presents the definition of the virtual space vectors for the general case of an n-level converter, suggests guidelines for designing virtual-space-vector PWM strategies, and provides the expressions of the phase duty-ratio waveforms corresponding to this family of PWMs. Modulations defined upon these vectors enable the use of diode-clamped topologies with passive front-ends. The performance of these converters operated with the proposed PWMs is compared to the performance of alternative designs through analysis,simulation and experiments.Postprint (published version