Search results for "YBA"
showing 10 items of 116 documents
An improved Flyback converter
2009
This paper presents a modified Flyback converter able to operate with higher efficiency and smaller size, overcoming most of the conventional flyback converter drawbacks, and also keeping its low cost and simplicity. In particular, the proposed converter allows the mosfet off voltage to be reduced and clamped to the input, thus recovering the transformer leakage energy. As a consequence, the duty cycle can be extended to unity, thus reducing the voltage stress across the output rectifier, and lowering both the magnetizing inductance and the transformer bias current values. In addition, due to the auxiliary mosfet, the magnetizing current can become negative, eliminating the discontinuous co…
Linear-non-linear digital control for dc/dc converters with fast transient response
2009
A linear-non-linear digital control for multi-module DC/DC converters that improves system stability, solves the limit-cycle problem, reduces recovery time and limits over- and under-shoots in regulated output voltage, is presented. A simulation model in Matlab-Simulink/Active-HDL mixed environment is described. Preliminary hardware tests on a single-phase step-down converter are reported. Simulation and experimental results are shown.
Identification and Robust Control of a Quadratic DC/DC Boost Converter by Hammerstein Model
2015
This paper deals with the theoretical framework definition and the experimental application of the Hammerstein (HM) identification and related robust control technique to a quadratic dc/dc single-switch boost (Q-boost) converter. A set of fourth-order transfer functions (TFs) has been identified with the Hammerstein approach, on the basis of a pseudorandom-binary-sequence (PRBS) excitation signal. The set of identified TFs has been then used to design a suitable robust control technique, able to properly deal with the converter parameter uncertainty and load variations. The proposed approach has been tested in numerical simulation and validated experimentally on a suitably developed test se…
High-Efficiency Regulation Method for a Zero-Current and Zero-Voltage Current-Fed Push–Pull Converter
2011
A new high-efficiency regulation method for a zero-current and zero-voltage current-fed push-pull converter is presented. The method proposed is based on the use of a controlled transformer as a post-regulator, which adds or subtracts an additional voltage to the output filter of the converter. An auxiliary regulator, which only handles a percentage of the output power, controls this transformer, and therefore, results in much higher efficiency than a normal preregulator would have. The novelty of the presented converter is that regulation is achieved without affecting the zero-voltage and zero-current switching in any working conditions. Small- and large-signal models of the converter have…
Dynamic modelling of a quadratic DC/DC single-switch boost converter
2017
This manuscript proposes the analysis of a Quadratic Boost Converter (QBC) transformer-less single switch typology. The state space average dynamic model and a constrained state space average model taking into account the mono-directional components of the converter (diodes, switches) have been analyzed. The static gain expression taking into consideration the parasitic elements of the converter and the small-signal transfer function of the QBC typology under study has been obtained. A sensitivity analysis has shown a high variation of the gain versus duty-cycle and of the derivative gain versus parasitic parameters of the converter in the range of the duty-cycle from 0.6 to 0.8 which is ra…
DC/DC converter topologies for electrolyzers: State-of-the-art and remaining key issues.
2017
In recent years, the use of electrolyzers to produce cleanly and efficiently hydrogen from renewable energy sources (i.e. wind turbines, photovoltaic) has taken advantage of a growing interest from researchers and industrial. Similarly to fuel cells, DC/DC converters are needed to interface the DC bus with the electrolyzer. Usually, electrolyzers require a low DC voltage to produce hydrogen from water. For this reason, a DC/DC buck converter is generally used for this purpose. However, other DC/DC converter topologies can be used depending on the feature of the electrolyzer and electrical grid as well. The main purpose of this paper is to present the current state-of-the-art of DC/DC conver…
Kinanthropometric Assessment of Individual, Collective and Fight Sport Players from the Spanish National Sport Technification Program
2020
Nowadays, the study of kinanthropometric parameters is an important tool for both early talent selection and for evaluating the efficacy of a training program. This study aimed to determine the anthropometric characteristics, body composition indicators and somatotype components of individual (athletics, swimming and triathlon), collective (handball and volleyball) and fight (karate and taekwondo) sportsmen and sportswomen from the Valencian Sports Technification Centre. This study involved a total of 62 men and 56 women, they were divided in three subgroups, including individual (athletics, swimming and triathlon), collective (handball and volleyball) and fight (karate and taekwondo) sport…
Effects of a Postural Exercise Program on Vertical Jump Height in Young Female Volleyball Players with Knee Valgus
2022
Background: Although a knee valgus position is related to the increase in injury risk in volleyball players, there is a lack of studies on the relationship between knee valgus and vertical jump (VJ) performance. Hence, the aim of this study was to investigate the effects of a postural exercise program on VJ height in young female volleyball players with knee valgus. Methods: This pilot study included 19 young female volleyball players divided into the following groups: the Valgus Experimental Group (VEG); the Valgus Control Group (VCG); and the Neutral Control Group (NCG). All three groups carried out the same volleyball training program. In addition, only the VEG underwent a 3-month postur…
Experimental study of the combined RES-based generators and electric storage systems for public buildings
2019
Abstract In the present paper, a new approach to the management of energy resources in the Research and Technology Centre of Energy (CRTEn -Tunisia) is proposed and evaluated by the monitoring of a PV installation realized for the cooperation project DE.DU.ENER.T, using renewable energy and economic criteria. The aim of this project is to improve energy efficiency order to minimize the electricity cost consumed at the CRTEn laboratory. According to the bills of electricity received, we noticed that there is a high consumption of electrical current. So, we targeted to install a photovoltaic field of 12KWc to reduce these bills by using the sustainable, green and clean sources. A theoretical …
Values and attributes of volleyball by the fans in the FIVB Men's World Championships 2014
2015
As the world of sport is encountering challenges, such as intensified competition, fragmented markets and loss of commitment, there is a need to discover new insights of the global sport consumers to gain more understanding of their behavior. Volleyball world is not an exception as regards the challenges. Despite its popularity, however, volleyball has not been researched as widely as for example football. The purpose of this master’s thesis was to investigate the image of volleyball through the perceived attributes the spectating fans link to this discipline in the context of an international tournament. Namely fans are the consumers in sport world and work as co-creators of sport events. …