Navegando por Assunto "Controle robusto"

Agora exibindo 1 - 3 de 3

Acesso aberto (Open Access)
Estratégias de controle de ordem fracionária aplicadas ao amortecimento de oscilações eletromecânicas em sistemas elétricos de potência
(Universidade Federal do Pará, 2014-08-11) AYRES JÚNIOR, Florindo Antonio de Carvalho; BARRA JUNIOR, Walter; http://lattes.cnpq.br/0492699174212608
In this work, a new project methodology was proposed to tune power systems stabilizers (PSS) based on fractional order systems theory (FOPSS). The strategy is based in a generalization of Lead-Lag compensators type project to fractional order transfer function domain. A new project variable, which defines the controller fractional order, is tuned to obtain a good compromise between the damping fulfillment of dominant electromechanical mode and the FOPSS amplified robustness. FOPSS performance was experimental evaluated, in a small-scalled system, located at Power Systems Laboratory of Federal University of Para. This test plant present a typical structure of synchronous generator connected to infinite bus and exhibits a decreased damping electromechanical dominant mode, whose around 1,2 Hz natural frequency value. So FOPSS was designed to improve relative damp of mode target, for all admissible operation range. For practical intent , first experimental tests was made to identify a plant nominal model in the form of a pulse transfer function, used in FOPSS project. This obtained model was validated and then used both to FOPSS project and conventional PSS (applied to performance comparison). The damp control rules of FOPSS were calculated, and then converted to difference equations, and subsequently, embedded in digital systems based on DSPIC microcontrollers. A couple of impulse test were made under different operational conditions. Respective dynamical responses data of plant output signals (active power deviation) and control effort were saved to analysis purposes. The experimental results showed that FOPSS presented a greater robustness and a similar performance compared to dynamical performance of conventional PSS, for all investigated operation range.
Acesso aberto (Open Access)
Investigação de estratégias de controle robusto multivariável descentralizado aplicadas à melhoria do desempenho de um conversor de potência CC/CC do tipo buck com estrutura single inductor multiple output
(Universidade Federal do Pará, 2018-02-05) MEDEIROS, Renan Landau Paiva de; BARRA JUNIOR, Walter; http://lattes.cnpq.br/0492699174212608
The DC/DC power converter systems are important devices to use in several applications in many sectors of the society. For this reason, several DC/DC converter topologies are developed to improve the performance of devices, aiming at reducing losses and improving the converter energy quality. However, such improvements should assess the control strategies that enable the correct functioning of the power converters. This works covers experimental assessment of the design of robust decentralized multivariable controller applied to a specific topology of the multivariable step-down power converter, where a single inductor element is shared by multiples outputs. Furthermore, it is important to ensure the system stability, as well as the multiple outputs regulations, however some difficulties remains, e.g., hard coupling between system’s outputs, non-linearities due to the inductive element and uncertainties due to imprecision of mathematical models and/or variation of nominal values of the discrete elements that compose the DC/DC converter. Aiming to assess the performance of the proposed design methodology for a multivariable robust controller, to perform experiments of parametric variations on the DC/DC power converter, it is developed several experimental tests and simulations using the Matlab. The results show the improved performance of the proposed methodology.
Acesso aberto (Open Access)
Projeto de controle robusto de ordem fracionária para sistemas com incerteza paramétrica
(Universidade Federal do Pará, 2024-10-21) GOMES, Marcus Ciro Martins; AYRES JÚNIOR, Florindo Antonio de Carvalho; http://lattes.cnpq.br/1919442364965261; COSTA JÚNIOR, Carlos Tavares da; http://lattes.cnpq.br/6328549183075122
This research introduces a novel methodology that integrates fractional-order control theory with robust control techniques to address parametric uncertainty, aimed at enhancing the performance of linear time-invariant uncertain systems with integer or fractional orders, referred to as Fractional-Order Robust Control (FORC). Unlike traditional methods, this proposed approach offers a new formulation of inequalitiesbased design, broadening the scope for discovering improved solutions through linear programming optimization. Consequently, fractional-order controllers are tailored to ensure desired transient and steady-state performance in closed-loop systems. In order to facilitate the digital implementation of the designed controller, the impulse response invariant discretization of fractional-order differentiators (IRID-FOD) is used to approximate fractional-order controllers to integer-order transfer functions. Additionally, the Hankel reduction order method is applied, making the controllers suitable for hardware deployment. Experimental tests conducted on a thermal system, along with assessment results based on time-domain responses and robustness analysis supported by performance indices and set value analysis, demonstrate the enhanced and robust performance of the proposed FORC methodology compared to classical robust control under parametric uncertainty.