A Detailed dSPACE-Based Implementation of Modulated Model Predictive Control for AC Microgrids

Microgrids represent a promising energy technology, because of the inclusion in them of clean and smart energy technologies. They also represent research challenges, including controllability, stability, and implementation. This article presents a dSPACE-control-platform-based implementation of a fixed-switching-frequency modulated model predictive control (M2PC) strategy, as an inner controller of a two-level, three-phase voltage source inverter (VSI) working in an islanded AC microgrid. The developed controller is hierarchical, as it includes a primary controller to share the load equally with the other power converter with its own local modulated predictive-based controller. All details of the implementation are given for establishing the dSPACE-based implementation of the control on a dSPACE ds1103 control platform, using MATLAB/Simulink for the controller design, I/O implementation and configuration with the embedded dSPACE’s real-time interface in Simulink, and then using the ControlDesk software for monitoring and testing of the real plant. The latter consists of the VSI operating with LCL filters, and sharing an RL load with a paralleled VSI with exactly the same controller. Finally, the obtained experimental waveforms are shown, with our respective conclusions representing this work, which is a very valuable tool for helping microgrid researchers implement dSPACE-based real-time simulations

A Process Asset Library to support Software Process Improvement in Small Settings

A main factor to the success of any organization process improvement effort is the Process Asset Library implementation that provides a central database accessible by anyone at the organization. This repository includes any process support materials to help process deployment. Those materials are composed of organization's standard software process, software process related documentation, descriptions of the software life cycles, guidelines, examples, templates, and any artefacts that the organization considers useful to help the process improvement. This paper describe the structure and contents of the Web-based Process Asset Library for Small businesses and small groups within large organizations. This library is structured using CMMI as reference model in order to implement those Process Areas described by this model

Predictive Control with Current-Based Maximum Power Point-Tracking for On-Grid Photovoltaic Applications

The high increase of renewable energy sources and the increment of distributed generation in the electrical grid has made them complex and of variable parameters, causing potential stability problems to the PI controllers. In this document, a control strategy for power injection to the electrical system from photovoltaic plants through a voltage source inverter two-level-type (VSI-2L) converter is proposed. The algorithm combines a current-based maximum power point-tracking (Current-Based MPPT) with model predictive control (MPC) strategy, allowing avoidance of the use of PI controllers and lowering of the dependence of high-capacitive value condensers. The sections of this paper describe the parts of the system, control algorithms, and simulated and experimental results that allow observation of the behavior of the proposed strategy

Efectos de las variables demograficas y los cambios en la edad de jubilacion sobre los aportes al Sistema de Seguridad Social. Trabajo de investigacion

Incluye BibliografíaPor razones practicas, se presenta un analisis vinculado con el origen de un tipo de financiamiento de las prestaciones del Sistema de Seguridad Social -el sistema de reparto- considerandose solo a la poblacion masculina de Uruguay, Chile y Honduras. El examen de la incidencia de las variables demograficas y de los cambios en la edad al jubilar en los aportes al sistema revela que: una poblacion creciente favorece al sistema por cuanto los aportes individuales requeridos para cubrir las jubilaciones seran menores; el aumento de la edad al jubilar disminuye los aportes personales para financiar las jubilaciones a otorgar; la variacion de la fecundidad afecta a los aportes en mayor medida que las variaciones en la mortalidad

Chile: mortalidad infantil por causas de defuncion basicas y multiples: 1972-1978. Trabajo final de investigacion

Incluye Bibliografí

Compatibilización de las clasificaciones internacionales de causas de muerte: aplicación a Chile (revisiones VII, VIII y IX), 1960-1982; informe preliminar

Incluye Bibliografí

Compatibilización de las revisiones séptima, octava y novena de la Clasificación Internacional de Enfermedades: aplicación a Chile, 1960-1985

Incluye Bibliografí

Fixed-Switching-Frequency Modulated Model Predictive Control for Islanded AC Microgrid Applications

In this paper, a fixed-switching-frequency modulated model predictive control (M2PC) is established for a two-level three-phase voltage source inverter (VSI) working in an islanded AC microgrid. These small-scale power systems are composed by two or more VSIs which interface DGs, controlling the voltage amplitude and frequency in the system, and simultaneously sharing the load active and reactive power. Generally, these operational characteristics are achieved using hierarchical linear control loops, but with challenging limitations such as slow transient reaction to disturbances and high proneness to be affected by parameter modifications. Model predictive control may solve these issues. Nevertheless, the most used and developed predictive control scheme, the finite-set model predictive control (FS-MPC), presents the drawback of having the harmonic spectrum spread over all the frequencies. This brings issues with coupling between the different hierarchical control levels of the whole microgrid system, and eventually, when designing the filters for main-grid connection. This paper aims to solve these issues by developing the fixed-switching-frequency M2PC working with higher-level control loops for operation in an islanded AC microgrid. These advantages are proved in an AC microgrid configuration where methodology for paralleling multiple M2PC-regulated VSIs is described, with rapid transient response, inherent stability, and fully decentralised operation of individual VSIs, achieving proper load power sharing, eliminating circular currents, and proper waveforms for output currents and capacitor voltages. All these achievements have been confirmed via simulation and experimental verification