Search results for: power trench MOSFET (U-MOSFET)
5210 Energy Management Method in DC Microgrid Based on the Equivalent Hydrogen Consumption Minimum Strategy
Authors: Ying Han, Weirong Chen, Qi Li
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An energy management method based on equivalent hydrogen consumption minimum strategy is proposed in this paper aiming at the direct-current (DC) microgrid consisting of photovoltaic cells, fuel cells, energy storage devices, converters and DC loads. The rational allocation of fuel cells and battery devices is achieved by adopting equivalent minimum hydrogen consumption strategy with the full use of power generated by photovoltaic cells. Considering the balance of the battery’s state of charge (SOC), the optimal power of the battery under different SOC conditions is obtained and the reference output power of the fuel cell is calculated. And then a droop control method based on time-varying droop coefficient is proposed to realize the automatic charge and discharge control of the battery, balance the system power and maintain the bus voltage. The proposed control strategy is verified by RT-LAB hardware-in-the-loop simulation platform. The simulation results show that the designed control algorithm can realize the rational allocation of DC micro-grid energy and improve the stability of system.Keywords: DC microgrid, equivalent minimum hydrogen consumption strategy, energy management, time-varying droop coefficient, droop control
Procedia PDF Downloads 3035209 Human Factors Issues and Measures in Advanced NPPs
Authors: Jun Su Ha
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Various advanced technologies will be adopted in Advanced Control Rooms (ACRs) of advanced Nuclear Power Plants (NPPs), which is thought to increase operators’ performance. However, potential human factors issues coupled with digital technologies might be troublesome. Human factors issues in ACRs are identified and strategies (or countermeasures) for evaluating and analyzing each of issues are addressed in this study.Keywords: advanced control room, human factor issues, human performance, human error, nuclear power plant
Procedia PDF Downloads 4705208 A Study on Effect of Dynamic Loading Speed on the Fracture Toughness of Equivalent Stress Gradient (ESG) Specimen
Authors: Moon Byung Woo, Seok Chang-Sung, Koo Jae-Mean, Kim Sang-Young, Choi Jae Gu, Huh Nam-Su
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Recently, the occurrence of the earthquake has increased sharply and many of the casualties have occurred worldwide, due to the influence of earthquakes. Especially, the Fukushima nuclear power plant accident which was caused by the earthquake in 2011 has significantly increased the fear of people and the demand for the safety of the nuclear power plant. Thus, in order to prevent the earthquake accident at nuclear power plant, it is important to evaluate the fracture toughness considering the seismic loading rate. To obtain fracture toughness for the safety evaluation of nuclear power plant, it is desirable to perform experiments with a real scale pipe which is expensive and hard to perform. Therefore, many researchers have proposed various test specimens to replicate the fracture toughness of a real scale pipe. Since such specimens have several problems, the equivalent stress gradient (ESG) specimen has been recently suggested. In this study, in order to consider the effects of the dynamic loading speed on fracture toughness, the experiment was conducted by applying five different kinds of test speeds using an ESG specimen. In addition, after we performed the fracture toughness test under dynamic loading with different speeds using an ESG specimen and a standard specimen, we compared them with the test results under static loading.Keywords: dynamic loading speed, fracture toughness, load-ratio-method, equivalent stress gradient (ESG) specimen
Procedia PDF Downloads 3095207 Smart Grids in Morocco: An Outline of the Recent Developments, Key Drivers, and Recommendations for Better Implementation
Authors: Mohamed Laamim, Abdelilah Rochd, Aboubakr Benazzouz, Abderrahim El Fadili
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Smart grids have recently sparked a lot of interest in the energy sector as they allow for the modernization and digitization of the existing power infrastructure. Smart grids have several advantages in terms of reducing the environmental impact of generating power from fossil fuels due to their capacity to integrate large amounts of distributed energy resources. On the other hand, smart grid technologies necessitate many field investigations and requirements. This paper focuses on the major difficulties that governments face around the world and compares them to the situation in Morocco. Also presented in this study are the current works and projects being developed to improve the penetration of smart grid technologies into the electrical system. Furthermore, the findings of this study will be useful to promote the smart grid revolution in Morocco, as well as to construct a strong foundation and develop future needs for better penetration of technologies that aid in the integration of smart grid features.Keywords: smart grids, microgrids, virtual power plants, digital twin, distributed energy resources, vehicle-to-grid, advanced metering infrastructure.
Procedia PDF Downloads 1405206 A Pole Radius Varying Notch Filter with Transient Suppression for Electrocardiogram
Authors: Ramesh Rajagopalan, Adam Dahlstrom
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Noise removal techniques play a vital role in the performance of electrocardiographic (ECG) signal processing systems. ECG signals can be corrupted by various kinds of noise such as baseline wander noise, electromyographic interference, and power-line interference. One of the significant challenges in ECG signal processing is the degradation caused by additive 50 or 60 Hz power-line interference. This work investigates the removal of power line interference and suppression of transient response for filtering noise corrupted ECG signals. We demonstrate the effectiveness of Infinite Impulse Response (IIR) notch filter with time varying pole radius for improving the transient behavior. The temporary change in the pole radius of the filter diminishes the transient behavior. Simulation results show that the proposed IIR filter with time varying pole radius outperforms traditional IIR notch filters in terms of mean square error and transient suppression.Keywords: notch filter, ECG, transient, pole radius
Procedia PDF Downloads 3775205 The Impact of Board of Directors on CEO Compensation: Evidence from the UK
Authors: Saleh Alagla, Murya Habbash
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The paper investigates whether the board of directors plays a monitoring role or not in CEO compensation for the UK firms during the eve of the recent financial crisis, 2004-2008. The use of heteroscedastic and autocorrelated error consistent estimation of the panel data shows, surprisingly, that four board characteristics variables are found to play a significant role in increasing the level of CEO compensation. This insightful result would suggest evidence of the managerial power theory in general and the cronyism hypothesis in particular. Moreover, the interesting evidence supporting managerial power perspective is that CEO-Chair duality reduces long-term compensation while increasing short-term compensation, thus suggesting that CEOs are risk averse who prefer short-term compensation to long-term compensation. Finally, consistent with the agency perspective board size is found to increase all compensation variables as expected.Keywords: corporate governance, CEO compensation, board of directors, internal governance mechanisms, agency theory, managerial power theory, cronyism hypothesis
Procedia PDF Downloads 8035204 Hybrid Finite Element Analysis of Expansion Joints for Piping Systems in Aircraft Engine External Configurations and Nuclear Power Plants
Authors: Dong Wook Lee
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This paper presents a method to analyze the stiffness of the expansion joint with structural support using a hybrid method combining computational and analytical methods. Many expansion joints found in tubes and ducts of mechanical structures are designed to absorb thermal expansion mismatch between their structural members and deal with misalignments introduced from the assembly/manufacturing processes. One of the important design perspectives is the system’s vibrational characteristics. We calculate the stiffness as a characterization parameter for structural joint systems using a combined Finite Element Analysis (FEA) and an analytical method. We apply the methods to two sample applications: external configurations of aircraft engines and nuclear power plant structures.Keywords: expansion joint, expansion joint stiffness, finite element analysis, nuclear power plants, aircraft engine external configurations
Procedia PDF Downloads 1115203 HPA Pre-Distorter Based on Neural Networks for 5G Satellite Communications
Authors: Abdelhamid Louliej, Younes Jabrane
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Satellites are becoming indispensable assets to fifth-generation (5G) new radio architecture, complementing wireless and terrestrial communication links. The combination of satellites and 5G architecture allows consumers to access all next-generation services anytime, anywhere, including scenarios, like traveling to remote areas (without coverage). Nevertheless, this solution faces several challenges, such as a significant propagation delay, Doppler frequency shift, and high Peak-to-Average Power Ratio (PAPR), causing signal distortion due to the non-linear saturation of the High-Power Amplifier (HPA). To compensate for HPA non-linearity in 5G satellite transmission, an efficient pre-distorter scheme using Neural Networks (NN) is proposed. To assess the proposed NN pre-distorter, two types of HPA were investigated: Travelling Wave Tube Amplifier (TWTA) and Solid-State Power Amplifier (SSPA). The results show that the NN pre-distorter design presents EVM improvement by 95.26%. NMSE and ACPR were reduced by -43,66 dB and 24.56 dBm, respectively. Moreover, the system suffers no degradation of the Bit Error Rate (BER) for TWTA and SSPA amplifiers.Keywords: satellites, 5G, neural networks, HPA, TWTA, SSPA, EVM, NMSE, ACPR
Procedia PDF Downloads 915202 Structural and Optical Properties of RF-Sputtered ZnS and Zn(S,O) Thin Films
Authors: Ould Mohamed Cheikh, Mounir Chaik, Hind El Aakib, Mohamed Aggour, Abdelkader Outzourhit
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Zinc sulfide [ZnS] and oxygenated zinc sulfide Zn(O,S) thin films were deposited on glass substrates, by reactive cathodic radio-frequency (RF) sputtering. The substrates power and percentage of oxygen were varied in the range of 100W to 250W and from 5% to 20% respectively. The structural, morphological and optical properties of these thin films were investigated. The optical properties (mainly the refractive index, absorption coefficient and optical band gap) were examined by optical transmission measurements in the ultraviolet-visible-near Infrared wavelength range. XRD analysis indicated that all sputtered ZnS films were a single phase with a preferential orientation along the (111) plane of zinc blend (ZB). The crystallite size was in the range of 19.5 nm to 48.5 nm, the crystallite size varied with RF power reaching a maximum at 200 W. The Zn(O,S) films, on the other hand, were amorphous. UV-Visible, measurements showed that the ZnS film had more than 80% transmittance in the visible wavelength region while that of Zn(O,S is 85%. Moreover, it was observed that the band gap energy of the ZnS films increases slightly from 3.4 to 3.52 eV as the RF power was increased. The optical band gap of Zn(O,S), on the other hand, decreased from 4.2 to 3.89 eV as the oxygen partial pressure is increased in the sputtering atmosphere at a fixed RF-power. Scanning electron microscopy observations revealed smooth surfaces for both type of films. The X-ray reflectometry measurements on the ZnS films showed that the density of the films (3.9 g/cm3) is close that of bulk ZnS.Keywords: thin films Zn(O, S) properties, Zn(O, S) by Rf-sputtering, ZnS for solar cells, thin films for renewable energy
Procedia PDF Downloads 2825201 The Influence of Thomson Effect on the Performance of N-Type Skutterudite Thermoelement
Authors: Anbang Liu, Huaqing Xie, Zihua Wu, Xiaoxiao Yu, Yuanyuan Wang
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Due to the temperature-dependence and mutual coupling of thermoelectric parameters, the Thomson effect always exists, which is derived from temperature gradients during thermoelectric conversion. The synergistic effect between the Thomson effect and non-equilibrium heat transport of charge carriers leads to local heat absorption or release in thermoelements, thereby affecting its power generation performance and conversion efficiency. This study verified and analyzed the influence and mechanism of the Thomson effect on N-type skutterudite thermoelement through quasi-steady state testing under approximate vacuum conditions. The results indicate the temperature rise/fall of N-type thermoelement at any position is affected by Thomson heat release/absorption. Correspondingly, the Thomson effect also contributes advantageously/disadvantageously to the output power of N-type skutterudite thermoelement when the Thomson coefficients are positive/negative. In this work, the output power can be promoted or decreased maximally by more than 27% due to the presence of Thomson heat when the absolute value of the Thomson coefficient is around 36 μV/℃.Keywords: Thomson effect, heat transport, thermoelectric conversion, numerical simulation
Procedia PDF Downloads 675200 Maximum Power Point Tracking Using Fuzzy Logic Control for a Stand-Alone PV System with PI Controller for Battery Charging Based on Evolutionary Technique
Authors: Mohamed A. Moustafa Hassan, Omnia S .S. Hussian, Hany M. Elsaved
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This paper introduces the application of Fuzzy Logic Controller (FLC) to extract the Maximum Power Point Tracking (MPPT) from the PV panel. In addition, the proportional integral (PI) controller is used to be the strategy for battery charge control according to acceptable performance criteria. The parameters of the PI controller have been tuned via Modified Adaptive Accelerated Coefficient Particle Swarm Optimization (MAACPSO) technique. The simulation results, using MATLAB/Simulink tools, show that the FLC technique has advantages for use in the MPPT problem, as it provides a fast response under changes in environmental conditions such as radiation and temperature. In addition, the use of PI controller based on MAACPSO results in a good performance in terms of controlling battery charging with constant voltage and current to execute rapid charging.Keywords: battery charging, fuzzy logic control, maximum power point tracking, PV system, PI controller, evolutionary technique
Procedia PDF Downloads 1665199 Dynamic Self-Scheduling of Pumped-Storage Power Plant in Energy and Ancillary Service Markets Using Sliding Window Technique
Authors: P. Kanakasabapathy, S. Radhika
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In the competitive electricity market environment, the profit of the pumped-storage plant in the energy market can be maximized by operating it as a generator, when market clearing price is high and as a pump, to pump water from lower reservoir to upper reservoir, when the price is low. An optimal self-scheduling plan has been developed for a pumped-storage plant, carried out on weekly basis in order to maximize the profit of the plant, keeping into account of all the major uncertainties such as the sudden ancillary service delivery request and the price forecasting errors. For a pumped storage power plant to operate in a real time market successive self-scheduling has to be done by considering the forecast of the day-ahead market and the modified reservoir storage due to the ancillary service request of the previous day. Sliding Window Technique has been used for successive self-scheduling to ensure profit for the plant.Keywords: ancillary services, BPSO, power system economics, self-scheduling, sliding window technique
Procedia PDF Downloads 4015198 Comparison between the Conventional Methods and PSO Based MPPT Algorithm for Photovoltaic Systems
Authors: Ramdan B. A. Koad, Ahmed F. Zobaa
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Since the output characteristics of Photovoltaic (PV) system depends on the ambient temperature, solar radiation and load impedance, its maximum Power Point (MPP) is not constant. Under each condition PV module has a point at which it can produce its MPP. Therefore, a Maximum Power Point Tracking (MPPT) method is needed to uphold the PV panel operating at its MPP. This paper presents comparative study between the conventional MPPT methods used in (PV) system: Perturb and Observe (P&O), Incremental Conductance (IncCond), and Particle Swarm Optimization (PSO) algorithm for (MPPT) of (PV) system. To evaluate the study, the proposed PSO MPPT is implemented on a DC-DC converter and has been compared with P&O and INcond methods in terms of their tracking speed, accuracy and performance by using the Matlab tool Simulink. The simulation result shows that the proposed algorithm is simple, and is superior to the P&O and IncCond methods.Keywords: photovoltaic systems, maximum power point tracking, perturb and observe method, incremental conductance, methods and practical swarm optimization algorithm
Procedia PDF Downloads 3585197 Power and Wear Reduction Using Composite Links of Crank-Rocker Mechanism with Optimum Transmission Angle
Authors: Khaled M. Khader, Mamdouh I. Elimy
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Reducing energy consumption became the major concern for all countries of the world during the recent decades. In general, power saving is currently the nominal goal of most industrial countries. It is well known that fossil fuels are the main pillar of development of world countries. Unfortunately, the increased rate of fossil fuel consumption will lead to serious problems caused by an expected depletion of fuels. Moreover, dangerous gases and vapors emission lead to severe environmental problems during fuel burning. Consequently, most engineering sectors especially the mechanical sectors are looking for improving any machine accompanied by reducing its energy consumption. Crank-Rocker planar mechanism is the most applied in mechanical systems. Besides, it is one of the most significant parts of the machines for obtaining the oscillatory motion. The transmission angle of this mechanism can be considered as an optimum value when its extreme values are equally varied around 90°. In addition, the transmission angle plays an important role in decreasing the required driving power and improving the dynamic properties of the mechanism. Hence, appropriate selection of mechanism links lengthens, which assures optimum transmission angle leads to decreasing the driving power. Moreover, mechanism's links manufactured from composite materials afford link's lightweight, which decreases the required driving torque. Furthermore, wear and corrosion problems can be treated through using composite links instead of using metal ones. This paper is dealing with improving the performance of crank-rocker mechanism using composite links due to their flexural elastic modulus values and stiffness in addition to high damping of composite materials.Keywords: Composite Material, Crank-Rocker Mechanism, Transmission angle, Design techniques, Power Saving
Procedia PDF Downloads 3045196 Julia-Based Computational Tool for Composite System Reliability Assessment
Authors: Josif Figueroa, Kush Bubbar, Greg Young-Morris
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The reliability evaluation of composite generation and bulk transmission systems is crucial for ensuring a reliable supply of electrical energy to significant system load points. However, evaluating adequacy indices using probabilistic methods like sequential Monte Carlo Simulation can be computationally expensive. Despite this, it is necessary when time-varying and interdependent resources, such as renewables and energy storage systems, are involved. Recent advances in solving power network optimization problems and parallel computing have improved runtime performance while maintaining solution accuracy. This work introduces CompositeSystems, an open-source Composite System Reliability Evaluation tool developed in Julia™, to address the current deficiencies of commercial and non-commercial tools. This work introduces its design, validation, and effectiveness, which includes analyzing two different formulations of the Optimal Power Flow problem. The simulations demonstrate excellent agreement with existing published studies while improving replicability and reproducibility. Overall, the proposed tool can provide valuable insights into the performance of transmission systems, making it an important addition to the existing toolbox for power system planning.Keywords: open-source software, composite system reliability, optimization methods, Monte Carlo methods, optimal power flow
Procedia PDF Downloads 735195 Evaluation of NASA POWER and CRU Precipitation and Temperature Datasets over a Desert-prone Yobe River Basin: An Investigation of the Impact of Drought in the North-East Arid Zone of Nigeria
Authors: Yusuf Dawa Sidi, Abdulrahman Bulama Bizi
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The most dependable and precise source of climate data is often gauge observation. However, long-term records of gauge observations, on the other hand, are unavailable in many regions around the world. In recent years, a number of gridded climate datasets with high spatial and temporal resolutions have emerged as viable alternatives to gauge-based measurements. However, it is crucial to thoroughly evaluate their performance prior to utilising them in hydroclimatic applications. Therefore, this study aims to assess the effectiveness of NASA Prediction of Worldwide Energy Resources (NASA POWER) and Climate Research Unit (CRU) datasets in accurately estimating precipitation and temperature patterns within the dry region of Nigeria from 1990 to 2020. The study employs widely used statistical metrics and the Standardised Precipitation Index (SPI) to effectively capture the monthly variability of precipitation and temperature and inter-annual anomalies in rainfall. The findings suggest that CRU exhibited superior performance compared to NASA POWER in terms of monthly precipitation and minimum and maximum temperatures, demonstrating a high correlation and much lower error values for both RMSE and MAE. Nevertheless, NASA POWER has exhibited a moderate agreement with gauge observations in accurately replicating monthly precipitation. The analysis of the SPI reveals that the CRU product exhibits superior performance compared to NASA POWER in accurately reflecting inter-annual variations in rainfall anomalies. The findings of this study indicate that the CRU gridded product is often regarded as the most favourable gridded precipitation product.Keywords: CRU, climate change, precipitation, SPI, temperature
Procedia PDF Downloads 895194 The Establishment and Application of TRACE/FRAPTRAN Model for Kuosheng Nuclear Power Plant
Authors: S. W. Chen, W. K. Lin, J. R. Wang, C. Shih, H. T. Lin, H. C. Chang, W. Y. Li
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Kuosheng nuclear power plant (NPP) is a BWR/6 type NPP and located on the northern coast of Taiwan. First, Kuosheng NPP TRACE model were developed in this research. In order to assess the system response of Kuosheng NPP TRACE model, startup tests data were used to evaluate Kuosheng NPP TRACE model. Second, the over pressurization transient analysis of Kuosheng NPP TRACE model was performed. Besides, in order to confirm the mechanical property and integrity of fuel rods, FRAPTRAN analysis was also performed in this study.Keywords: TRACE, safety analysis, BWR/6, FRAPTRA
Procedia PDF Downloads 5635193 Towards a New Spinozistic Democracy: Power and/ or Virtue
Authors: Cetin Balanuye
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The present study aims to accomplish two tasks: First, it critically reinterprets the actual relationship between democracy and the modern state in order to show that it is responsible for most of our current political problems and dilemmas. Second, it is argued that this relationship can be reimagined for better, and Spinozistic notions such as ‘conatus’, ‘power’ and ‘virtue’ are crucial in this pursuit. The significance of the present study lies in several interrelated observations: The world has never been a more heterogeneous place than today. People from different religious, cultural and historical backgrounds do equally have 'good reasons' to hold that their world views are the best ones. We have almost no authority to be respected equally by all these different world views. We no longer have gods at once we had in our ancient times. We have three big monotheistic religions, yet the God of which is significantly different from each other. The worse is that the believers of these religions do not seem eager to perform a duet, but rather tend to fight a duel with each other. Thanks to post-modernism, neither reason nor science is any longer seen as universally value-neutral guide to be employed in our search for a common ground. In sum, the question 'how should I live?' has never generated this much diversity before in terms of answers and the answers have never been this much away from a fairly objective evaluation. Our so-called liberal democracies are supposed to perform against this heterogenous, antagonistic and self-sustained web of discursive background. It is argued that our conception of 'State' with a weak emphasis on democracy is not a solution, if not itself the source of this topsy-turvy. Weak emphasis on democracy should be understood here as a kind of liberal democracy which operates in a partisan State, one which takes sides among rivals either for this or against that world view. This conception of State rests on a misleading understanding of the concept of power, and it is argued that it can only be corrected by means of a Spinoza-informed ontology of politics. The role of State in such an ontology is no longer a partisanship of any kind, nor is it representative of all-encompassing authority to favor any world view. State in this Spinozistic ontology equally encourages world views and their discursive practices to let them increase the power of acting and have more power to affect rules and regulations. World views can enhance every medium -in the sense of nonviolence ethology- to increase their power of acting. The more active a world view is, the more powerful and the more virtuous it is in terms of its effective power on the State. Though Spinoza has provided us with a limited guideline to understand what kind of democracy, he actually had in his mind, his ontology developed in Ethics is rich enough to imagine and inspire a better democratic practice to help us sustain the modern State in our extremely pluralistic contemporary societies.Keywords: democracy, Islam, power, Spinoza
Procedia PDF Downloads 2095192 3 Phase Induction Motor Control Using Single Phase Input and GSM
Authors: Pooja S. Billade, Sanjay S. Chopade
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This paper focuses on the design of three phase induction motor control using single phase input and GSM.The controller used in this work is a wireless speed control using a GSM technique that proves to be very efficient and reliable in applications.The most common principle is the constant V/Hz principle which requires that the magnitude and frequency of the voltage applied to the stator of a motor maintain a constant ratio. By doing this, the magnitude of the magnetic field in the stator is kept at an approximately constant level throughout the operating range. Thus, maximum constant torque producing capability is maintained. The energy that a switching power converter delivers to a motor is controlled by Pulse Width Modulated signals applied to the gates of the power transistors in H-bridge configuration. PWM signals are pulse trains with fixed frequency and magnitude and variable pulse width. When a PWM signal is applied to the gate of a power transistor, it causes the turn on and turns off intervals of the transistor to change from one PWM period.Keywords: index terms— PIC, GSM (global system for mobile), LCD (Liquid Crystal Display), IM (Induction Motor)
Procedia PDF Downloads 4485191 A Study of Electric Generation Characteristics for Thin-Film Piezoelectric PbZrTiO₃ Ceramic Plate during the Static and Cyclic Loading Conditions
Authors: Tsukasa Ogawa, Mitsuhiro Okayasu
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To examine the generation properties of electric power for piezoelectric (PbZrTiO3) ceramic plates, the electric-power generation characteristics were examined experimentally and numerically during cyclic bending under various loading fixtures with different contact condition, i.e., point and area contact. In the low applied loading condition between 10 and 50 N, increasing the load-contact area on the piezoelectric ceramic led to a nonlinear decrease in the generated voltage. Decreasing contact area, including the point contact, basically enhanced the generated voltage, although the voltage saturated during loading when the contact area is less than ϕ5 mm, which was attributed to the high strain status, resulting in the material failure, i.e., high stress concentration. In this case, severe plastic deformation and the domain switching were dominated failure modes in the ceramic. From this approach, it is clear that the applied load became more larger (50 ~100 N), larger contact area (ϕ10 ~ ϕ20 mm) became advantageous for power generation. Based upon this cyclic loading was carried out to investigate the fatigue characteristics of the piezoelectric ceramic late. For all contact conditions, electric voltage dropped in the beginning of the cyclic loading, although the higher electric generation was stable in the further cyclic loading for the contact area of ϕ10 ~ ϕ20 mm. In constant, further decrement of electric generation occurred for the point contact condition, and the low electric voltage was generated for the larger contact condition.Keywords: electric power generation, piezoelectric ceramic, lead zirconate titanate ceramic, loading conditions
Procedia PDF Downloads 1685190 Energy Consumption Estimation for Hybrid Marine Power Systems: Comparing Modeling Methodologies
Authors: Kamyar Maleki Bagherabadi, Torstein Aarseth Bø, Truls Flatberg, Olve Mo
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Hydrogen fuel cells and batteries are one of the promising solutions aligned with carbon emission reduction goals for the marine sector. However, the higher installation and operation costs of hydrogen-based systems compared to conventional diesel gensets raise questions about the appropriate hydrogen tank size, energy, and fuel consumption estimations. Ship designers need methodologies and tools to calculate energy and fuel consumption for different component sizes to facilitate decision-making regarding feasibility and performance for retrofits and design cases. The aim of this work is to compare three alternative modeling approaches for the estimation of energy and fuel consumption with various hydrogen tank sizes, battery capacities, and load-sharing strategies. A fishery vessel is selected as an example, using logged load demand data over a year of operations. The modeled power system consists of a PEM fuel cell, a diesel genset, and a battery. The methodologies used are: first, an energy-based model; second, considering load variations during the time domain with a rule-based Power Management System (PMS); and third, a load variations model and dynamic PMS strategy based on optimization with perfect foresight. The errors and potentials of the methods are discussed, and design sensitivity studies for this case are conducted. The results show that the energy-based method can estimate fuel and energy consumption with acceptable accuracy. However, models that consider time variation of the load provide more realistic estimations of energy and fuel consumption regarding hydrogen tank and battery size, still within low computational time.Keywords: fuel cell, battery, hydrogen, hybrid power system, power management system
Procedia PDF Downloads 365189 Optimal Design of Multimachine Power System Stabilizers Using Improved Multi-Objective Particle Swarm Optimization Algorithm
Authors: Badr M. Alshammari, T. Guesmi
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In this paper, the concept of a non-dominated sorting multi-objective particle swarm optimization with local search (NSPSO-LS) is presented for the optimal design of multimachine power system stabilizers (PSSs). The controller design is formulated as an optimization problem in order to shift the system electromechanical modes in a pre-specified region in the s-plan. A composite set of objective functions comprising the damping factor and the damping ratio of the undamped and lightly damped electromechanical modes is considered. The performance of the proposed optimization algorithm is verified for the 3-machine 9-bus system. Simulation results based on eigenvalue analysis and nonlinear time-domain simulation show the potential and superiority of the NSPSO-LS algorithm in tuning PSSs over a wide range of loading conditions and large disturbance compared to the classic PSO technique and genetic algorithms.Keywords: multi-objective optimization, particle swarm optimization, power system stabilizer, low frequency oscillations
Procedia PDF Downloads 4315188 A Feminist Critical Discourse Analysis of Selected Marvel Comics
Authors: Onaza Ajmal
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The purpose of the study is to explore the power relations linguistically and visually with reference to the representation of gender, race, violence, and empowerment through male characters and female superheroes from the two selected Marvel comics, Ms. Marvel (2014) and Captain Marvel (2019-). The study also aims to elaborate on the different cultural backgrounds of female superheroes and their choices and behaviors concerning the male characters. Moreover, it also seeks to explore whether the female superheroes reassert or resists the established gender roles. Using the tenets of critical discourse analysis (CDA) and feminist critical discourse analysis (FCDA) by Lazar (2005), the study analyzed the power relations from a feminist viewpoint. The linguistic analysis of textual features such as ‘adjectives’, ‘lexical items’, ‘metaphors’, and ‘use of pronouns’, etc., found in the selected comics is carried out under the framework of CDA given by Fairclough (1989). Kress and van Leeuwen's model of reading images (2006) are used to analyze the visual images in this study. The findings of the study show that despite the empowering nature of female superheroes, the unequal power relations between male and female characters are established linguistically and visually, which further sustains and reinforces the racial and patriarchal gender ideologies in the selected comics. Moreover, it is recommended that the female representations in the feminist themes of empowerment with respect to the Pakistani female superheroes should also be explored for further research.Keywords: feminist critical discourse analysis, patriarchal gender ideology, power relations, superhero comics
Procedia PDF Downloads 1745187 Design and Advancement of Hybrid Multilevel Inverter Interface with PhotoVoltaic
Authors: P.Kiruthika, K. Ramani
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This paper presented the design and advancement of a single-phase 27-level Hybrid Multilevel DC-AC Converter interfacing with Photo Voltaic. In this context, the Multicarrier Pulse Width Modulation method can be implemented in 27-level Hybrid Multilevel Inverter for generating a switching pulse. Perturb & Observer algorithm can be used in the Maximum Power Point Tracking method for the Photo Voltaic system. By implementing Maximum Power Point Tracking with three separate solar panels as an input source to the 27-level Hybrid Multilevel Inverter. This proposed method can be simulated by using MATLAB/simulink. The result shown that the proposed method can achieve silky output wave forms, more flexibility in voltage range, and to reduce Total Harmonic Distortion in medium-voltage drives.Keywords: Multi Carrier Pulse Width Modulation Technique (MCPWM), Multi Level Inverter (MLI), Maximum Power Point Tracking (MPPT), Perturb and Observer (P&O)
Procedia PDF Downloads 5795186 Case Study: Throughput Analysis over PLC Infrastructure as Last Mile Residential Solution in Colombia
Authors: Edward P. Guillen, A. Karina Martinez Barliza
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Powerline Communications (PLC) as last mile solution to provide communication services, has the advantage of transmitting over channels already used for electrical distribution. However these channels have been not designed with this purpose, for that reason telecommunication companies in Colombia want to know how good would be using PLC in costs and network performance in comparison to cable modem or DSL. This paper analyzes PLC throughput for residential complex scenarios using a PLC network scenarios and some statistical results are shown.Keywords: home network, power line communication, throughput analysis, power factor, cost, last mile solution
Procedia PDF Downloads 2665185 The Belt and Road Initiative in a Spiderweb of Conflicting Great Power Interests: A Geopolitical Analysis
Authors: Csaba Barnabas Horvath
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The Belt and Road initiative of China is one that can change the face of Eurasia as we know it. Instead of four major, densely populated subcontinents defined by Mackinder (East Asia, Europe, the Indian Subcontinent, and the Middle East) isolated from each other by vast, sparsely populated and underdeveloped regions, it can at last start to function as a geographic whole, with a sophisticated infrastructure linking its different parts to each other. This initiative, however, happens not in a geopolitical vacuum, but in a space of conflicting great power interests. In Central Asia, the influence of China and Russia are in a setting of competition, where despite the cooperation between the two powers to a great degree, issues causing mutual mistrust emerge repeatedly. In Afghanistan, besides western military presence, even India’s efforts can be added to the picture. In Southeast Asia, a key region regarding the maritime Silk Road, India’s Act East policy meets with China’s Belt and Road, not always in consensus, not to mention US and Japanese interests in the region. The presentation aims to take an overview on how conflicting great power interests are likely to influence the outcome of the Belt and Road initiative. The findings show, that overall success of the Belt and Road Initiative may not be as smooth, as hoped by China, but at the same time, in a limited number of strategically important countries (such as Pakistan, Laos, and Cambodia), this setting is actually a factor favoring China, providing at least a selected number of reliable corridors, where the initiative is actually likely to be successful.Keywords: belt and road initiative, geostrategic corridors, geopolitics, great power rivalry
Procedia PDF Downloads 2205184 Grid Architecture Model for Smart Grid
Authors: Nick Farid, Roghoyeh Salmeh
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The planning and operation of the power grid is becoming much more complex because of the introduction of renewable energy resources, the digitalization of the electricity industry, as well as the coupling of efficiency and greener energy trends. These changes, along with new trends, make interactions between grid users and the other stakeholders more complex. This paper focuses on the main “physical” and “logical” interactions between grid users and the grid stakeholders, both from power system equipment and information management standpoints, and proposes a new interoperability model for Smart Grids.Keywords: user interface, interoperability layers, grid architecture framework, smart grid
Procedia PDF Downloads 955183 Hierarchical Operation Strategies for Grid Connected Building Microgrid with Energy Storage and Photovoltatic Source
Authors: Seon-Ho Yoon, Jin-Young Choi, Dong-Jun Won
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This paper presents hierarchical operation strategies which are minimizing operation error between day ahead operation plan and real time operation. Operating power systems between centralized and decentralized approaches can be represented as hierarchical control scheme, featured as primary control, secondary control and tertiary control. Primary control is known as local control, featuring fast response. Secondary control is referred to as microgrid Energy Management System (EMS). Tertiary control is responsible of coordinating the operations of multi-microgrids. In this paper, we formulated 3 stage microgrid operation strategies which are similar to hierarchical control scheme. First stage is to set a day ahead scheduled output power of Battery Energy Storage System (BESS) which is only controllable source in microgrid and it is optimized to minimize cost of exchanged power with main grid using Particle Swarm Optimization (PSO) method. Second stage is to control the active and reactive power of BESS to be operated in day ahead scheduled plan in case that State of Charge (SOC) error occurs between real time and scheduled plan. The third is rescheduling the system when the predicted error is over the limited value. The first stage can be compared with the secondary control in that it adjusts the active power. The second stage is comparable to the primary control in that it controls the error in local manner. The third stage is compared with the secondary control in that it manages power balancing. The proposed strategies will be applied to one of the buildings in Electronics and Telecommunication Research Institute (ETRI). The building microgrid is composed of Photovoltaic (PV) generation, BESS and load and it will be interconnected with the main grid. Main purpose of that is minimizing operation cost and to be operated in scheduled plan. Simulation results support validation of proposed strategies.Keywords: Battery Energy Storage System (BESS), Energy Management System (EMS), Microgrid (MG), Particle Swarm Optimization (PSO)
Procedia PDF Downloads 2485182 Estimation of Synchronous Machine Synchronizing and Damping Torque Coefficients
Authors: Khaled M. EL-Naggar
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Synchronizing and damping torque coefficients of a synchronous machine can give a quite clear picture for machine behavior during transients. These coefficients are used as a power system transient stability measurement. In this paper, a crow search optimization algorithm is presented and implemented to study the power system stability during transients. The algorithm makes use of the machine responses to perform the stability study in time domain. The problem is formulated as a dynamic estimation problem. An objective function that minimizes the error square in the estimated coefficients is designed. The method is tested using practical system with different study cases. Results are reported and a thorough discussion is presented. The study illustrates that the proposed method can estimate the stability coefficients for the critical stable cases where other methods may fail. The tests proved that the proposed tool is an accurate and reliable tool for estimating the machine coefficients for assessment of power system stability.Keywords: optimization, estimation, synchronous, machine, crow search
Procedia PDF Downloads 1405181 Authority and Function of Administrative Organs According to the Constitution: A Construction of Democracy in the Administrative Law of Indonesia
Authors: Andhika Danesjvara, Nur Widyastanti
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The constitution regulates the forms, types, and powers of sState organs in a government. The powers of the organs are then regulated in more detail in the legislation. One of these organs is a government organ, headed by a president or by another name that serves as the main organizer of government. The laws and regulations will govern how the organs of government shall exercise their authority and functions. In a modern state, the function of enacting laws or called executive power does not exercise the functions of government alone, but there are other organs that help the government run the country. These organs are often called government agencies, government accelerating bodies, independent regulatory bodies, commissions, councils or other similar names. The legislation also limits the power of officials within the organs to keep from abusing its authority. The main question in this paper is whether organs are the implementation of a democratic country, or as a form of compromise with the power of stakeholders. It becomes important to see how the administrative organs perform their functions. The administrative organs that are bound by government procedures work in the public service; therefore the next question is how far the function of public service is appropriate and not contradictory to the constitution.Keywords: administrative organs, constitution, democracy, government
Procedia PDF Downloads 303