Governança de TI nas universidades federais brasileiras: uma abordagem integrada

This research has as an objective to study the IT Governance in the Brazilian Federal Universities, discusses the relationships between the IT Governance (ITG) mechanisms and the noticed IT management development in those public institutions. The subject Information Technology Governance, is not only vast, but constitutes implications in most different operational and knowledge areas, being relevant to the Public Administration, as a part of Corporative Governance and the public related, evolves high investments, such as financial, structure and material and human resources. The universities are entities from Indirect Administration and essential actors in the knowledge developing and creating and on its managers. Theirs public administrative agents, responds for the managing public resources competence and to provide internal policy that determines how IT will allow a bigger alignment and reaching of institutions business. We highlight the role of universities that manage significant quantity of public resources to achieve its institutional purposes. Looking this way, this theoretical and empirical study has as its goal to design an ITG panorama in the Brazilian universities (67 universities), for the strategic alignment on governance actions and institutional development focusing on the efficiency of the public service offered by those institutions. Facing this research focus delimitation, the methodology process will evolve three investigative activities: (1) documental and bibliographical research, (2) questioning, and exploratory tool, to investigate the IT Governance and Management perception in the IFES, directed to IT executive responsible, as a data collection device and (3) research the availability of ITG information in institutes websites. This project contributes to the studies this subject; it investigates the relations that make the ITG as a business strategy and shows the implementation IT Governance, such as a tool to allow the viability of Corporate Governance. This way, expected to contributes to the Public Administration development, following the principle that to improve it’s needed diagnose, and then, offer better results to the society on this field of working.

Comparação do controle do inversor trifásico conectado à rede com filtro LCL considerando o amortecimento passivo e ativo

Distributed generation systems must fulfill standards specifications of current harmonics injected to the grid. In order to satisfy these grid requirements, passive filters are connected between inverter and grid. This work compares the characteristic response of the traditional inductive (L) filter with the inductive-capacitive-inductive (LCL) filter. It is shown that increasing the inductance L leads to a good ripple current suppression around the inverter switching frequency. The LCL filter provides better harmonic attenuation and reduces the filter size. The main drawback is the LCL filter impedance, which is characterized by a typical resonance peak, which must be damped to avoid instability. Passive or active techniques can be used to damp the LCL resonance. To address this issue, this dissertation presents a comparison of current control for PV grid-tied inverters with L filter and LCL filter and also discuss the use of active and passive damping for different regions of resonance frequency. From the mathematical models, a design methodology of the controllers was developed and the dynamic behavior of the system operating in closed loop was investigated. To validate the studies developed during this work, experimental results are presented using a three-phase 5kW experimental platform. The main components and their functions are discussed in this work. Experimental results are given to support the theoretical analysis and to illustrate the performance of grid-connected PV inverter system. It is shown that the resonant frequency of the system, and sampling frequency can be associated in order to calculate a critical frequency, below which is essential to perform the damping of the LCL filter. Also, the experimental results show that the active buffer per virtual resistor, although with a simple development, is effective to damp the resonance of the LCL filter and allow the system to operate stable within predetermined parameters.