Active vibration control of a blade element with uncertainty modeling in PZT actuator force

2019 ◽  
Vol 25 (21-22) ◽  
pp. 2721-2732
Author(s):  
Selim Sivrioglu ◽  
Fevzi Cakmak Bolat ◽  
Ercan Erturk
Keyword(s):  
Steady State ◽  
Active Vibration Control ◽  
State Space Model ◽  
Uncertainty Modeling ◽  
Aerodynamic Load ◽  
Mixed Norm ◽  
Multi Objective ◽  
Dependent Part ◽  
Parameter Dependent ◽  
Blade Element

The aim of this research is to attenuate the vibrations of a blade structure with an attached piezoelectric actuator using robust multi-objective control. The force obtained from a piezoelectric patch loading has uncertainties due to the complicated shape (airfoil) of the blade element. A parameter-dependent model of the force equation is developed to understand the possible variation range of the actuation force. The modal analysis of the blade is performed to find vibration mode frequencies, and an aerodynamic load is generated experimentally to create steady-state vibration on the blade. A state-space model is obtained by considering certain vibration modes and the parameter-dependent part of the force in the input vector is taken outside of the plant model. The robust stability filter is modified with parameter dependency to have a cluster of the filter. Two different multi-objective controllers are designed with different design objectives. The designed controllers are implemented in experiments and performances of the controllers are compared using frequency and time domain responses. It is shown that the flexible blade vibrations are successfully suppressed with the proposed mixed norm robust controllers under the effect of steady-state aerodynamic disturbance with different air speeds. It is observed in experimental results that the performances of the [Formula: see text] controller are better than the [Formula: see text] controller.

Active vibration suppression of elastic blade structure: Using a novel magnetorheological layer patch

2018 ◽  
Vol 29 (19) ◽  
pp. 3792-3803 ◽  
Author(s):  
Fevzi Cakmak Bolat ◽  
Selim Sivrioglu
Keyword(s):  
Wind Turbine ◽  
Vibration Suppression ◽  
State Space Model ◽  
Interaction Model ◽  
Parametric Uncertainty ◽  
Small Scale ◽  
Aerodynamic Load ◽  
Active Vibration Suppression ◽  
Active Vibration ◽  
Blade Element

This research study proposes a new active control structure to suppress vibrations of a small-scale wind turbine blade with attached magnetorheological fluid patch actuated by an electromagnet. The blade structure is manufactured by an aluminum extrusion machine considering the airfoil data of SH3055 which is designed for use on a small wind turbine. An interaction model between the magnetorheological patch and the electromagnetic actuator is derived and a force characterization is realized. A norm-based multiobjective H2/ H∞ controller is designed using the state-space model of the elastic blade element. The H2/ H∞ controller is experimentally implemented under the steady-state aerodynamic load conditions. The results of experiments show that the magnetorheological layer patch is effective for suppressing vibrations of the blade structure and robust against parametric uncertainty.

scholarly journals Modeling and Optimizing the Multi-Objective Portfolio Optimization Problem with Trapezoidal Fuzzy Parameters

2021 ◽  
Vol 26 (2) ◽  
pp. 36
Author(s):  
Alejandro Estrada-Padilla ◽  
Daniela Lopez-Garcia ◽  
Claudia Gómez-Santillán ◽  
Héctor Joaquín Fraire-Huacuja ◽  
Laura Cruz-Reyes ◽  
...  
Keyword(s):  
Steady State ◽  
Portfolio Optimization ◽  
Optimization Problem ◽  
Solution Process ◽  
Density Estimator ◽  
Nsga Ii ◽  
Spatial Spread ◽  
Multi Objective ◽  
Significant Difference ◽  
Portfolio Optimization Problem

A common issue in the Multi-Objective Portfolio Optimization Problem (MOPOP) is the presence of uncertainty that affects individual decisions, e.g., variations on resources or benefits of projects. Fuzzy numbers are successful in dealing with imprecise numerical quantities, and they found numerous applications in optimization. However, so far, they have not been used to tackle uncertainty in MOPOP. Hence, this work proposes to tackle MOPOP’s uncertainty with a new optimization model based on fuzzy trapezoidal parameters. Additionally, it proposes three novel steady-state algorithms as the model’s solution process. One approach integrates the Fuzzy Adaptive Multi-objective Evolutionary (FAME) methodology; the other two apply the Non-Dominated Genetic Algorithm (NSGA-II) methodology. One steady-state algorithm uses the Spatial Spread Deviation as a density estimator to improve the Pareto fronts’ distribution. This research work’s final contribution is developing a new defuzzification mapping that allows measuring algorithms’ performance using widely known metrics. The results show a significant difference in performance favoring the proposed steady-state algorithm based on the FAME methodology.

scholarly journals Performance comparison of generational and steady-state asynchronous multi-objective evolutionary algorithms for computationally-intensive problems

2015 ◽  
Vol 87 ◽  
pp. 47-60 ◽  
Author(s):  
Alexandru-Ciprian Zăvoianu ◽  
Edwin Lughofer ◽  
Werner Koppelstätter ◽  
Günther Weidenholzer ◽  
Wolfgang Amrhein ◽  
...  
Keyword(s):  
Steady State ◽  
Evolutionary Algorithms ◽  
Performance Comparison ◽  
Multi Objective ◽  
Computationally Intensive

scholarly journals Small-Signal Stability Analysis of Multi-Terminal DC Grids

Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 130
Author(s):  
Amr Radwan
Keyword(s):  
Steady State ◽  
State Space ◽  
State Space Model ◽  
Operation Time ◽  
Power Sharing ◽  
Voltage Source ◽  
Small Signal ◽  
Small Signal Stability ◽  
Steady State Operation ◽  
The Individual

This paper presents a detailed small-signal analysis and an improved dc power sharing scheme for a six terminal dc grid. The multi-terminal DC (MTDC) system is composed of (1) two voltage-source converters (VSCs) entities operating as rectification stations; (2) two VSCs operating as inverting stations; (3) two dc/dc conversion stations; and (4) an interconnected dc networking infrastructure. The small-signal state-space sub-models of the individual entities are developed and integrated to formulate the state-space model of the entire system. Using the modal analysis, it is shown that the most critical modes are associated with the power sharing droop coefficients of the rectification stations, which are constrained by the steady-state operational requirements. Therefore, a second degree-of-freedom compensation scheme is proposed to improve the dynamic response of the MTDC system without influencing the steady-state operation. Time domain simulation results are presented to validate the analysis and show the effectiveness of the proposed techniques.

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