Research in power electronics and control

Fault-tolerance is one of the most interesting feature of wind energy conversion systems (WECS). The ability to maintain operation even after an open-phase fault, allows for the system operators to maintain energy production, providing tangible economic benefits.CONACYT – Consejo Nacional de Ciencia y Tecnologí

De la Leña a las energías renovables: aplicaciones de la Electrónica de Potencia

Proyectos desarrollados por la FIUNA: Principales Proyectos, principales Aportes y proyecciones.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

Documentação de Calidris pusilla (Aves, Charadriidae) no Paraguai

Se documenta por primera vez la presencia del playero Calidris pusilla en Paraguay, a través de fotografías tomadas de presumiblemente un solo individuo en Laguna Capitán, Departamento de Presidente Hayes durante el 12-13 de mayo de 2017. Se indican menciones previas (basadas en observaciones) de la especie en el país.The presence of Semipalmated Sandpiper Calidris pusilla in Paraguay is documented for the first through photographs taken, of presumably the same individual, at Laguna Capitán, Presidente Hayes deparment, during 12-13 May 2017. A summary is provided of previous records (sight only observations) of the species in the country.A presença do maçarico-rasteirinho Calidris pusilla no Paraguai é documentada pela primeira vez, através de fotografias tiradas, presumivelmente, de um único indivíduo em Laguna Capitán, Departamento de Presidente Hayes, de 12 a 13 de maio de 2017. As menções anteriores (com base em observações) são indicadas das espécies no país.Facultad de Ciencias Naturales y Muse

Multi-modular matrix converter topology applied to distributed generation systems

In this paper, a multi-modular matrix converter (MMC) topology as the power conversion core to interconnect a six-phase wind energy generator to the grid is proposed and analyzed theoretically. The proposed architecture is useful in distributed generation systems, where each module consists of a three-phase matrix converter topology. Furthermore, a model-based predictive control will be applied to the MMC in order to evaluate the dynamic performance in the design of current control. Finally, simulation results based on a MatLab/Simulink will be discussed in order to highlight the most relevant characteristic of the proposed MMC topology.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

Active and Reactive Power Control Strategy for Grid-Connected Six-Phase Generator by using Multi-Modular Matrix Converters

Este artículo propone una estrategia de control de potencia activa y reactiva basada en enfoques de control predictivo aplicados a sistemas de energía renovable conectados a la red.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

Predictive current control with reactive power minimization in six-phase wind energy generator using multi-modular direct matrix converter

Increasing worldwide energy demand and well known pollution effects of fossil fuels, make necessary to develop new environmentally friendly energy generation systems such as wind energy. In this research a predictive current control with reactive power reduction is proposed for a six-phase energy generator - multi-modular matrix converter system. The proposal shows a significant harmonic reduction in the generator side and a THD less than 0.6% at the load side, with good current tracking, making it suitable for further grid interconnection.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

A Randomized Study of Nutritional Supplementation in Patients with Unilateral Wet Age-Related Macular Degeneration

Carotenoides; Marcadors inflamatoris; Àcids grassos poliinsaturatsCarotenoides; Marcadores inflamatorios; Ácidos grasos poliinsaturadosCarotenoids; Inflammatory markers; Polyunsaturated fatty acidsThe purpose of this study is evaluate the efficacy and safety of medicinal products containing the original Age-Related Eye Disease group (AREDS) formulation at doses approved in Europe (EU, control group; n = 59) with a product that adds DHA, lutein, zeaxanthin, resveratrol and hydroxytyrosol to the formula (intervention group; n = 50). This was a multicenter, randomized, observer-blinded trial conducted in patients aged 50 years or older diagnosed with unilateral exudative Age related Macular Degeneration AMD. At month 12, the intervention did not have a significant differential effect on visual acuity compared with the control group, with an estimated treatment difference in Early Treatment Diabetic Retinopathy Study (ETDRS) of −1.63 (95% CI −0.83 to 4.09; p = 0.192). The intervention exhibited a significant and, in most cases, relevant effect in terms of a reduction in some inflammatory cytokines and a greater improvement in the fatty acid profile and serum lutein and zeaxantin concentration. In patients with unilateral wet AMD, the addition of lutein, zeaxanthin, resveratrol, hydroxytyrosol and DHA to the AREDS EU recommended doses in the short-term did not have a differential effect on visual acuity compared to a standard AREDS EU formula but, in addition to improving the fatty acid profile and increasing carotenoid serum levels, may provide a beneficial effect in improving the proinflammatory and proangiogenic profile of patients with AMD.The research was funded by Laboratorios Théa (Barcelona, Spain) and by research grants from the “Instituto de Salud Carlos III/European Regional Development Fund (ERDF)” and RD16/0008/0011, OFTARED: Enfermedades oculares: “Prevención, detección precoz, tratamiento y rehabilitación de las patologías oculares”

Predictive power control strategy for a Grid-Connected 2L-VSI with fixed switching frequency

In the recent years, model predictive control has been consolidated as a design strategy and an attractive alternative for the control of power electronic devices. This paper proposes an active and reactive power control strategy based on predictive control approach applied to grid-connected renewable energy systems. To accomplish this, a three-phase two-level voltage source inverter based topology is used in combination with a simple and efficient fixed-frequency modulation technique. Results based on a MATLAB/Simulink simulation environment are discussed and the most relevant characteristics of the proposed fixed-frequency predictive control approach are highlighted considering the total harmonic distortion as a figure of merit.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

A novel predictive-fixed switching frequency technique for a cascade H-bridge multilevel STATCOM

There are several control techniques for active power filter applications. This paper presents a new alternative of predictive current control for a cascade H-bridge multilevel converter, where the optimal vector selected by the predictive controller is used for a modulation stage to obtain a fixed switching frequency. Simulation results validate the proposal where almost similar results can be obtained in comparison with the traditional methods.CONACYT – Consejo Nacional de Ciencia y Tecnologí