Factores psicológicos en tenis. Control del estrés y su relación con los parámetros fisiológicos. Psychological factors in tennis. Control of stress and its relation with physiological parameters

El tenis es un deporte en el que se manifiestan las diversas cualidades físicas de una formamuy específica y en clara interrelación con factores técnicos, tácticos y psicológicos.Continuamente se producen acciones cognitivas con toma de decisión y diversas variacionesen el posible grado de ansiedad del jugador. Como actividad de relación con un oponente yante tareas abiertas variables, se produce una íntima y continua conexión entre nuestro mediointerno y el medio externo. Esto determina que los procesos psicológicos, hormonales, metabólicos,histológicos, biomecánicos, etc., se manifiesten de forma más o menos interrelacionaday compleja. Con el fin de aportar información sobre el comportamiento psicológico y surelación con los parámetros fisiológicos realizaremos un análisis un análisis teórico del estrésy su manifestación y control durante el juego

Pre-Calculated Duty Cycle Control Implemented in FPGA for Power Factor Correction

A power factor correction (PFC) technique based on pre-calculated duty cycle values is presented in this paper. In this method the duty ratios for half a line period are calculated in advance and stored in a memory. By synchronizing the memory with the line, near unity power factors can be achieved in a specific operating point. The main advantage of this technique is that neither current measurement nor current loop are needed. To obtain stable output voltages a voltage loop is included. A boost converter prototype controlled by an FPGA evaluation board has been implemented in order to verify the functionality of the proposed method. Both the simulation and experimental results show that near unity power factor can be achieved with this PFC strategy

Review and Comparison of Step-Up Transformerless Topologies for Photovoltaic AC-Module Application

This paper presents a comprehensive review of stepup single-phase non-isolated inverters suitable for ac-module applications. In order to compare the most feasible solutions of the reviewed topologies, a benchmark is set. This benchmark is based on a typical ac-module application considering the requirements for the solar panels and the grid. The selected solutions are designed and simulated complying with the benchmark obtaining passive and semiconductor components ratings in order to perform a comparison in terms of size and cost. A discussion of the analyzed topologies regarding the obtained ratings as well as ground currents is presented. Recommendations for topological solutions complying with the application benchmark are provided

Corrección del factor de potencia, sin medida de corriente, mediante implementación en FPGA de one-cycle control

En este artículo se presenta una técnica de control digital de correctores de factor de potencia (CFP) trabajando en modo de conducción continua en la que no es necesario el uso de sensor de corriente ni de convertidor analógico-digital de alta velocidad. La corriente de entrada al CFP se estima a partir de la descripción del modelo en VHDL de un convertidor elevador y de las muestras digitales de las tensiones de entrada y salida del convertidor. El objetivo final es desarrollar un controlador universal para CFP, con posibilidad de trabajar varios convertidores idénticos en paralelo y así aumentar la potencia. En este trabajo se abordan las diferentes soluciones ante los problemas que aparecen en el desarrollo del prototipo de laboratorio y se presentan resultados en diferentes condiciones, comparando el contenido armónico de la corriente con los límites establecidos por la normativa vigente más restrictiv

Multiphase Parallel Interleaved And Primary-Parallel Secondary-Series Forward Micro-Inverter Comparison.

Using multiphase technique is interesting in PV AC-module application due to light-load efficiency improvement by applying phase shedding, and the possibility of low-profile implementation. This paper presents a comparison, in terms of size and efficiency, of the parallel interleaved and the parallel-series connected multiphase configurations, as a function of the number of phases, for a forward micro-inverter operated in DCM. 8-phase prototypes of both multiphase configurations are built and compared between them and with the single phase forward micro-inverter, validating the presented analysis

Current sensorless power factor correction based on digital current rebuilding

A new digital control technique for power factor correction is presented. The main novelty of the method is that there is no current sensor. Instead, the input current is digitally rebuilt, using the estimated input current for the current loop. Apart from that, the ADCs used for the acquisition of the input and output voltages have been designed ad-hoc. Taking advantage of the slow dynamic behavior of these voltages, almost completely digital ADCs have been designed, leaving only a comparator and an RC filter in the analog part. The final objective is obtaining a low cost digital controller which can be easily integrated in an ASIC along with the controller of paralleled and subsequent power section

A simple DC-UPS based in forward-forward topology, design and simulation

This paper presents the analysis, design and simulation of a simple DC-UPS converter with integrated back-up and automatic transition. This converter makes automatic transitions between the main AC and the battery when a failure occurs; and it delivers uninterrupted DC power to the load through two independent power sources of commercial input power and battery power. The converter has the following characteristics: automatic transition between the main and the battery, no additional control to detect failure in main, single structure, galvanic isolation, multi output voltages capability and only one switch control for two operation modes: normal and back-up. The analysis, design and simulation for this converter are presented

Differential-mode EMI reduction in a multiphase DCM flyback converter

Switched converters are a source of electromagnetic interference (EMI) due to the hard switching and abrupt edges in the current and voltage waveforms. Multiphase converters can reduce the EMI at the source, minimizing the conducted EMI generation, without changing dramatically the normal operation of the circuit. Input filter can be greatly reduced, radiated EMI is lower, and internal EMI problems are minimized. This paper is focused on exploring multiphase converters as a topological technique to reduce conducted differential-mode EMI generation at the source, considering some no idealities of the multiphase converter

Isolated DC-DC UPS based in a forward-forward converter analysis and design

This paper presents the analysis, design and simulation from a simple DC-UPS converter with integrated back-up and automatic transition. This converter makes automatic transition between the main AC and the battery when a failure occurs, and it delivers uninterrupted DC power to the load through two independent power sources of commercial input power and battery power. The converter has the following characteristics: automatic transition between the main and the battery, no additional control to detect failure in the main, single structure, galvanic isolation, multi output voltages capability and only one switch control for two operation modes normal and back-up. The analysis, design, simulation and experimental results for this converter are presented