scholarly journals Design and dSPACE Implementation of a Simplified Fuzzy Control of a DC-DC Three-Level Converter

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Hajar Doubabi ◽  
Issam Salhi
Keyword(s):  
Control Strategy ◽  
Boost Converter ◽  
Operating Conditions ◽  
Operating Range ◽  
Performance Specification ◽  
Output Tracking Control ◽  
Converter Topology ◽  
The Stability ◽  
Level Converter ◽  
Takagi Sugeno

The design of an efficient DC-DC converter depends critically on its suitable control. In this paper, a new simplified output tracking control strategy for a DC-DC three-level boost converter is presented. The proposed strategy is characterized by its good tracking performances, its simplicity of design, and the stability that is ensured over the entire operating range. Thanks to (i) the adopted Takagi–Sugeno (TS) fuzzy approach; (ii) the small-signal model derived under the large domain of operating conditions, and (iii) the proportional-integral (PI) controllers’ merit. After introducing the three-level boost converter topology, the operating principles and mathematical modeling are addressed. Then, the proposed output control strategy is developed based on the PI control and the TS fuzzy approximation. A controller ensuring the capacitor voltages balancing has been also introduced in this paper. Experimental results using dSPACE (DS1104) and a laboratory prototype of three-level boost converter demonstrate the flexibility of the proposed controller, its reference tracking capability, and its ability to satisfy the performance specification over the whole operating range of the system.

scholarly journals A Unified Control Strategy of Distributed Generation for Grid-Connected and Islanded Operation Conditions Using an Artificial Neural Network

2021 ◽  
Vol 13 (11) ◽  
pp. 6388
Author(s):  
Karim M. El-Sharawy ◽  
Hatem Y. Diab ◽  
Mahmoud O. Abdelsalam ◽  
Mostafa I. Marei
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Control System ◽  
Distributed Generation ◽  
Control Strategy ◽  
Current Control ◽  
Operating Conditions ◽  
Pi Controllers ◽  
Artificial Neural ◽  
The Stability

This article presents a control strategy that enables both islanded and grid-tied operations of a three-phase inverter in distributed generation. This distributed generation (DG) is based on a dramatically evolved direct current (DC) source. A unified control strategy is introduced to operate the interface in either the isolated or grid-connected modes. The proposed control system is based on the instantaneous tracking of the active power flow in order to achieve current control in the grid-connected mode and retain the stability of the frequency using phase-locked loop (PLL) circuits at the point of common coupling (PCC), in addition to managing the reactive power supplied to the grid. On the other side, the proposed control system is also based on the instantaneous tracking of the voltage to achieve the voltage control in the standalone mode and retain the stability of the frequency by using another circuit including a special equation (wt = 2πft, f = 50 Hz). This utilization provides the ability to obtain voltage stability across the critical load. One benefit of the proposed control strategy is that the design of the controller remains unconverted for other operating conditions. The simulation results are added to evaluate the performance of the proposed control technology using a different method; the first method used basic proportional integration (PI) controllers, and the second method used adaptive proportional integration (PI) controllers, i.e., an Artificial Neural Network (ANN).

Mathematical Model of Three-Phase Boost Converter

2012 ◽  
Vol 507 ◽  
pp. 96-100
Author(s):  
Zhong Zhang ◽  
Wei Ming Tong
Keyword(s):  
Mathematical Model ◽  
Nonlinear Control ◽  
Control Strategy ◽  
Boost Converter ◽  
Analysis Method ◽  
Topology Structure ◽  
Conservation Of Energy ◽  
Three Phase ◽  
Converter Topology ◽  
The Mathematical Model

Now the nonlinear control strategy used by a lot of power electronic converters is not dependent on the mathematical model of the system. They are only based on the error of control variables to control the output voltage or other variables, and this leads to the shortcomings of poor control and not easy to optimize. The fundamental reason is that they are not based on the mathematical model of converter topology structure. This paper presents a new way to build mathematical model. The paper established the unified mathematical model of the three-phase Boost converter topology structure by studied the three-phase Boost converter topology structure deeply and based on the law of conservation of energy and combined with small-signal modeling analysis method, and done the systematic analysis for it. The analysis method is also applicable to other converter topology, such as the buck, buck-boost, etc., and the model not only can be used in the controller design, can also provide a theoretical basis for the applications of a new nonlinear control strategy.

scholarly journals A Novel Solution for the Elimination of Mode Switching in Pump-Controlled Single-Rod Cylinders

Actuators ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 20 ◽  
Author(s):  
Petter H. Gøytil ◽  
Damiano Padovani ◽  
Michael R. Hansen
Keyword(s):  
Control Strategy ◽  
Operating Conditions ◽  
Mode Switching ◽  
Loss Of Control ◽  
Unstable Behavior ◽  
Wide Range ◽  
Stability Issue ◽  
Underlying Mechanisms ◽  
The Stability ◽  
Proper Operation

This paper concerns the stability issue of pump-controlled single-rod cylinders, known as mode switching. First, a review of the topic is provided. Thereafter, the most recently proposed solution for the elimination of mode switching is investigated and shown to result in unstable behavior under certain operating conditions. A theoretical analysis is provided demonstrating the underlying mechanisms of this behavior. Based on the analysis, a novel control strategy is proposed and investigated numerically. Proper operation and stability are demonstrated for a wide range of operating conditions, including situations under which the most recently proposed solution results in unstable behavior and loss of control over the actuator.

scholarly journals T-S Fuzzy Model Based Control Strategy for the Networked Suspension Control System of Maglev Train

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Guang He ◽  
Jie Li ◽  
Peng Cui ◽  
Yun Li
Keyword(s):  
Control System ◽  
Control Strategy ◽  
State Feedback ◽  
Fuzzy Model ◽  
Maglev Train ◽  
Fuzzy Models ◽  
Physical Experiments ◽  
Suspension Control ◽  
The Stability ◽  
Takagi Sugeno

The control problem for the networked suspension control system of maglev train with random induced time delay and packet dropouts is investigated. First, Takagi-Sugeno (T-S) fuzzy models are utilized to represent the discrete-time nonlinear networked suspension control system, and the parameters uncertainties of the nonlinear model have also been taken into account. The controllers take the form of parallel distributed compensation. Then, a sufficient condition for the stability of the networked suspension control system is derived. Based on the criteria, the state feedback fuzzy controllers are obtained, and the controller gains can be computed by using MATLAB LMI Toolbox directly. Finally, both the numerical simulations and physical experiments on the full-scale single bogie of CMS-04 maglev train have been accomplished to demonstrate the effectiveness of this proposed method.

scholarly journals Gas Turbine Heat Recovery Systems Predicting Fired Performance

1985 ◽  
Author(s):  
Akber Pasha
Keyword(s):  
Gas Turbine ◽  
Heat Recovery ◽  
Operating Conditions ◽  
Design Parameters ◽  
Process Equipment ◽  
Operating Condition ◽  
Operating Range ◽  
Gas Turbine Exhaust ◽  
The Stability ◽  
Turbine Exhaust

Heat recovery systems generate steam by extracting heat from the gas turbine exhaust. This steam is used either in a steam turbine to generate power or as a heating and drying medium in a process. Most of the time it is a combination of both. Because of the cogeneration criteria and because of the independent power and process equipment, the HRS can no longer depend on gas turbine exhaust alone to produce the needed steam. Some sort of induct auxiliary firing is employed to satisfy the steam demand. The HRS, therefore, is needed to operate satisfactorily at various ambients and loads and at fired and unfired conditions. The design of the HRS should take into consideration all of these unfired and fired conditions so that the HRS operation can be stable over the operating range. There are numerous design parameters which affect the design and operational stability of the HRS and all these need to be reviewed at each operating condition for the design to be satisfactory. This paper presents charts and graphs which predict the probable values of these design parameters under various operating conditions. By utilizing these, the HRS user can establish the stability of the HRS performance over the operating range based on the specified design point parameters. If there is undesirable performance at a certain point, then either the operating condition or the design parameters can be changed. An HRS user can, by using these charts, be able to specify more realistic design parameters without a lengthly analysis by the HRS manufacturer which costs both money and time.

scholarly journals Effects of wastewater type on stability and operating conditions control strategy in relation to the formation of aerobic granular sludge – a review

2021 ◽  
Author(s):  
N. A. Hamiruddin ◽  
N. A. Awang ◽  
S. F. Mohd Shahpudin ◽  
N. S. Zaidi ◽  
M. A. M. Said ◽  
...  
Keyword(s):  
Control Strategy ◽  
Extracellular Polymeric Substances ◽  
Structural Model ◽  
Granular Sludge ◽  
Operating Conditions ◽  
Aerobic Granular Sludge ◽  
Microbial Distribution ◽  
Thickness Variability ◽  
Standard Operating Condition ◽  
The Stability

Abstract Currently, research trends on aerobic granular sludge (AGS) have integrated the operating conditions of extracellular polymeric substances (EPS) towards the stability of AGS systems in various types of wastewater with different physical and biochemical characteristics. More attention is given to the stability of the AGS system for real site applications. Although recent studies have reported comprehensively the mechanism of AGS formation and stability in relation to other intermolecular interactions such as microbial distribution, shock loading and toxicity, standard operating condition control strategy for different types of wastewater have not yet been discussed. Thus, the dimensional multi-layer structural model of AGS is discussed comprehensively in the first part of this review paper, focusing on diameter size, thickness variability of each layer and diffusion factor. This can assist in facilitating the interrelation between disposition and stability of AGS structure to correspond to the changes in wastewater types, which is the main objective and novelty of this review.

Coverage and Stability of NHx Terminated Cobalt and Ruthenium Surfaces: a First Principles Investigation

2019 ◽  
Author(s):  
Ji Liu ◽  
Michael Nolan
Keyword(s):  
Metal Surfaces ◽  
High Vacuum ◽  
Atomic Layer ◽  
Nitrogen Plasma ◽  
Operating Conditions ◽  
Ultra High Vacuum ◽  
Bridge Site ◽  
Stable Surface ◽  
Saturation Coverage ◽  
The Stability

<div>In the atomic layer deposition (ALD) of Cobalt (Co) and Ruthenium (Ru) metal using nitrogen plasma, the structure and composition of the post N-plasma NHx terminated (x = 1 or 2) metal surfaces are not well known but are important in the subsequent metal containing pulse. In this paper, we use the low-index (001) and (100) surfaces of Co and Ru as models of the metal polycrystalline thin films. The (001) surface with a hexagonal surface structure is the most stable surface and the (100) surface with a zigzag structure is the least stable surface but has high reactivity. We investigate the stability of NH and NH2 terminations on these surfaces to determine the saturation coverage of NHx on Co and Ru. NH is most stable in the hollow hcp site on (001) surface and the bridge site on the (100) surface, while NH2 prefers the bridge site on both (001) and (100) surfaces. The differential energy is calculated to find the saturation coverage of NH and NH2. We also present results on mixed NH/NH2-terminations. The results are analyzed by thermodynamics using Gibbs free energies (ΔG) to reveal temperature effects on the stability of NH and NH2 terminations. Ultra-high vacuum (UHV) and standard ALD</div><div>operating conditions are considered. Under typical ALD operating conditions we find that the most stable NHx terminated metal surfaces are 1 ML NH on Ru (001) surface (350K-550K), 5/9 ML NH on Co (001) surface (400K-650K) and a mixture of NH and NH2 on both Ru (100) and Co (100) surfaces.</div>

Towards a new design with generic modeling and adaptive control of a transformable quadrotor

2021 ◽  
pp. 1-31
Author(s):  
S.H. Derrouaoui ◽  
Y. Bouzid ◽  
M. Guiatni
Keyword(s):  
Adaptive Control ◽  
Control Strategy ◽  
Experimental Tests ◽  
Generic Model ◽  
System Control ◽  
System A ◽  
Viable Solution ◽  
Generic Modeling ◽  
Adaptive Control Strategy ◽  
The Stability

Abstract Recently, transformable Unmanned Aerial Vehicles (UAVs) have become a subject of great interest in the field of flying systems, due to their maneuverability, agility and morphological capacities. They can be used for specific missions and in more congested spaces. Moreover, this novel class of UAVs is considered as a viable solution for providing flying robots with specific and versatile functionalities. In this paper, we propose (i) a new design of a transformable quadrotor with (ii) generic modeling and (iii) adaptive control strategy. The proposed UAV is able to change its flight configuration by rotating its four arms independently around a central body, thanks to its adaptive geometry. To simplify and lighten the prototype, a simple mechanism with a light mechanical structure is proposed. Since the Center of Gravity (CoG) of the UAV moves according to the desired morphology of the system, a variation of the inertia and the allocation matrix occurs instantly. These dynamics parameters play an important role in the system control and its stability, representing a key difference compared with the classic quadrotor. Thus, a new generic model is developed, taking into account all these variations together with aerodynamic effects. To validate this model and ensure the stability of the designed UAV, an adaptive backstepping control strategy based on the change in the flight configuration is applied. MATLAB simulations are provided to evaluate and illustrate the performance and efficiency of the proposed controller. Finally, some experimental tests are presented.

scholarly journals Performance of Iron-Functionalized Activated Carbon Catalysts (Fe/AC-f) on CWPO Wastewater Treatment

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 337
Author(s):  
Sara Mesa Medina ◽  
Ana Rey ◽  
Carlos Durán-Valle ◽  
Ana Bahamonde ◽  
Marisol Faraldos
Keyword(s):  
Wastewater Treatment ◽  
Activated Carbon ◽  
Landfill Leachate ◽  
Surface Composition ◽  
Treatment Plant ◽  
Reaction Medium ◽  
Pollutant Removal ◽  
Operating Conditions ◽  
Water Matrix ◽  
The Stability

Two commercial activated carbon were functionalized with nitric acid, sulfuric acid, and ethylenediamine to induce the modification of their surface functional groups and facilitate the stability of corresponding AC-supported iron catalysts (Fe/AC-f). Synthetized Fe/AC-f catalysts were characterized to determine bulk and surface composition (elemental analysis, emission spectroscopy, XPS), textural (N2 isotherms), and structural characteristics (XRD). All the Fe/AC-f catalysts were evaluated in the degradation of phenol in ultrapure water matrix by catalytic wet peroxide oxidation (CWPO). Complete pollutant removal at short reaction times (30–60 min) and high TOC reduction (XTOC = 80 % at ≤ 120 min) were always achieved at the conditions tested (500 mg·L−1 catalyst loading, 100 mg·L−1 phenol concentration, stoichiometric H2O2 dose, pH 3, 50 °C and 200 rpm), improving the results found with bare activated carbon supports. The lability of the interactions of iron with functionalized carbon support jeopardizes the stability of some catalysts. This fact could be associated to modifications of the induced surface chemistry after functionalization as a consequence of the iron immobilization procedure. The reusability was demonstrated by four consecutive CWPO cycles where the activity decreased from 1st to 3rd, to become recovered in the 4th run. Fe/AC-f catalysts were applied to treat two real water matrices: the effluent of a wastewater treatment plant with a membrane biological reactor (WWTP-MBR) and a landfill leachate, opening the opportunity to extend the use of these Fe/AC-f catalysts for complex wastewater matrices remediation. The degradation of phenol spiked WWTP-MBR effluent by CWPO using Fe/AC-f catalysts revealed pH of the reaction medium as a critical parameter to obtain complete elimination of the pollutant, only reached at pH 3. On the contrary, significant TOC removal, naturally found in complex landfill leachate, was obtained at natural pH 9 and half stoichiometric H2O2 dose. This highlights the importance of the water matrix in the optimization of the CWPO operating conditions.

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