Multilevel power converters have been aim of research in the last years due to their advantages when compared to traditional two-level topologies: better harmonic performance, filters reduction, lower components volta...
Multilevel power converters have been aim of research in the last years due to their advantages when compared to traditional two-level topologies: better harmonic performance, filters reduction, lower components voltage stress and higher power process capability. Following this trend, the present work proposes two SEPIC DC-DC converters composed of multilevel flying capacitor asymmetric totem-pole switching cell. These structures are achieved by replacing one leg of switch/diode of the traditional two-level asymmetric totem-pole cell by a similar multilevel flying capacitor cell. An operation analysis of the proposed converter is presented, as well as hardware-in-the-loop real-time simulation results to validate the theoretical approach.
This paper proposes a three-phase three-level AC/DC converter with reduced number of controlled switches and high-frequency DC-bus based on NPC (Neutral Point Clamped) topology, for unidirectional power flow applicati...
This paper proposes a three-phase three-level AC/DC converter with reduced number of controlled switches and high-frequency DC-bus based on NPC (Neutral Point Clamped) topology, for unidirectional power flow applications. Galvanic isolation is reached by using a center tap transformer, which requires only a full-bridge at it primary side. No bulky electrolytic capacitors are needed on the DC-bus, in contrast to conventional multilevel topologies. A PWM strategy with carriers arranged in alternating phase opposition (PWM-APOD) is used to operate the proposed converter. The applied PWM technique is able to operate the converter stage on the AC side with only two switches commuting per switching period. The switches of the isolated pulsating DC/DC converter are commutated with half the switching frequency of the converter on the AC side. A dual-loop control strategy with PI voltage and PI resonant current controllers is adopted to ensure reference load voltage and almost sinusoidal grid currents. Simulation and experimental results are presented to validate the proposed converter operation.
This paper describes a proof of concept of an Internet of Things (IoT) module, with wireless communication, sensing and energy harvesting capabilities. A self-adaptable power approach for balancing energy consumption ...
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This work proposes using the You Only Look Once (YOLO) architecture for defect detection in suspension polymeric insulators from images. Firstly, an image dataset of 138 kV polymeric suspension insulators was develope...
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ISBN:
(数字)9798350374988
ISBN:
(纸本)9798350374995
This work proposes using the You Only Look Once (YOLO) architecture for defect detection in suspension polymeric insulators from images. Firstly, an image dataset of 138 kV polymeric suspension insulators was developed. Then, the dataset was augmented by horizontal and vertical flips to increase the training data. Afterward, YOLOv8n and YOLOv8s architectures were trained and used to detect insulator defects from the captured images. The developed models can detect four insulator defects: exposed rod, end fitting corrosion, cracks, and damaged sheds. Finally, the trained models were evaluated based on precision, recall, mean Average Precision (mAP), and confusion matrix. The results showed that YOLOv8s presented satisfactory results and potential for deploying and experimentation on UAVs to monitor polymeric insulators.
This article implements the multi-objective grey wolf optimizer (MOGWO) in the identification process of a multivariable system. For a sequence of 100 runs, MOGWO approach had compared and analyzed with the grey wolf ...
This article implements the multi-objective grey wolf optimizer (MOGWO) in the identification process of a multivariable system. For a sequence of 100 runs, MOGWO approach had compared and analyzed with the grey wolf optimizer (GWO), the single-objective version. In the computational simulation, the determination coefficient values and mean square error had used to analyze the quality of the models obtained. In the results, MOGWO showed superior to GWO to the differences between the order of magnitude of the system outputs. The implementation shows that MOGWO and other multi-objective metaheuristics can be an alternative method to solve problems of identification processes of multivariable systems.
Efficient production planning requires well-structured models compatible with metaheuristic and other optimization techniques. This study compares three established metaheuristic methods - sanitized-teaching-learning-...
Efficient production planning requires well-structured models compatible with metaheuristic and other optimization techniques. This study compares three established metaheuristic methods - sanitized-teaching-learning-based optimization (s-TLBO), Particle Swarm Optimization (PSO), and Differential Evolution (DE) with a termination criterion of equal number of functional evaluations - for profit-maximizing production planning. The focus is on a single-level problem involving complex constraints, non-linear costs, budget and raw material limitations. The paper presents two solution strategies: a penalty-based and a correction-based approach. Analyzing 300 unique instances of the problem reveals that s-TLBO implemented with correction-based approach consistently outperforms the other methods in devising optimal production plans for two Saudi Arabian petrochemical industries with 24 products, 54 processes, and three raw materials for plant 1 and two raw materials for plant 2.
To enhance production planning efficiency, it’s crucial to have well-structured models that align with metaheuristic and other optimization techniques. This research conducts a comparative analysis of three unique me...
To enhance production planning efficiency, it’s crucial to have well-structured models that align with metaheuristic and other optimization techniques. This research conducts a comparative analysis of three unique metaheuristic methods: sanitized-teaching-learning-based optimization (sTLBO), Particle Swarm Optimization (PSO), and Differential Evolution (DE) with a termination criterion of equal number of functional evaluations. The primary focus lies on profit-maximizing production planning within a single-level framework, encompassing intricate domain constraints, nonlinear costs, budget limitations and raw material constraints. The paper introduces three correction-based solution approaches. Upon evaluating 300 distinct instances of the problem, the study reveals that s-TLBO integrated with correction-based approach 1 and 3 consistently outperforms the other methods when it comes to devising optimal production plans for a Saudi Arabian petrochemical industry. This industry scenario involves 24 products, 54 processes, and three raw materials.
This work presents a performance comparison between the newly developed Manta Ray Foraging Optimization (MRFO) and two different variants created for tuning a decentralized fractional order proportional-integral-deriv...
This work presents a performance comparison between the newly developed Manta Ray Foraging Optimization (MRFO) and two different variants created for tuning a decentralized fractional order proportional-integral-derivative (FOPID) controller for a multiple-input multiple-output (MIMO) application. The application consists of a ball mill pulverizing system to pulverize coal and maximize fuel efficiency. MRFO and its applications have the task of finding the optimal controller variable values to control the system's temperature and pressure. The MRFO is a metaheuristic based on the behavior of manta rays, and although it shows efficient performance it may be improved through the use of techniques which generate new variants of the algorithm. Two techniques were used in the de-velopment of new variants: Quantum mechanics and opposition-based learning. The three different versions of MRFO were used to minimize a custom fitness function which is a combination of the integral time squared error (ITSE) and the overshoot of the system response. Simulations were carried using Simulink and Matlab softwares. For analyzing the performances, statistical measures such as minimum, maximum, best, mean, median, and standard deviation of the fitness function over 50 runs were used. Additionally, the different variants were also compared for minimizing 10 benchmark functions. The results show that the use of the previously mentioned techniques improve the performance of the original MRFO in optimizing the FOPID to control the ball mill pulverizing system.
Attention-deficit hyperactivity disorder (ADHD) affects at least 5% of the world population. ADHD typically starts in childhood and can affect normal development that can cause serious consequences during adulthood. M...
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In this paper, we propose a model for the rapid characterization of MOS-type capacitors in the accumulation region. Closed-form analytical expressions have been used to estimate the equivalent circuit elements, which ...
In this paper, we propose a model for the rapid characterization of MOS-type capacitors in the accumulation region. Closed-form analytical expressions have been used to estimate the equivalent circuit elements, which are calculated as a function of the design parameters of the layout and of the technological process. To verify the modeling carried out, a set of MOS capacitors with different geometries were simulated in ADS® and the main characteristics of the capacitor were compared. Based on the model, an analysis/optimization was implemented in MATLAB® in order to determine the capacitor/cell layout parameters that optimize its structure, based on a figure of merit. Compared to another work in the literature, the proposed method showed a chip-area reduction of 20.82% and an ESR of 16.38% smaller for the same capacitance value. Capacitor optimization not only contributes to reducing costs but also to improving the performance of the circuit it will make part of.
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