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Records Added in January 2019
Records added in January 2019
Change year: 2018 | 2019
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Showing records 196 to 220 of 220. [First] Page: 1 5 6 7 8 9 Last
On Real-Time Fault Detection in Wind Turbines: Sensor Selection Algorithm and Detection Time Reduction Analysis
Francesc Pozo, Yolanda Vidal, Josep M. Serrahima
January 7, 2019 (v1)
Keywords: FAST, Fault Detection, hypothesis test, principal component analysis, sensor selection
In this paper, we address the problem of real-time fault detection in wind turbines. Starting from a data-driven fault detection method, the contribution of this paper is twofold. First, a sensor selection algorithm is proposed with the goal to reduce the computational effort of the fault detection method. Second, an analysis is performed to reduce the data acquisition time needed by the fault detection method, that is, with the goal of reducing the fault detection time. The proposed methods are tested in a benchmark wind turbine where different actuator and sensor failures are simulated. The results demonstrate the performance and effectiveness of the proposed algorithms that dramatically reduce the number of sensors and the fault detection time.
Control of a Dual-Stator Flux-Modulated Motor for Electric Vehicles
Xinhua Guo, Shaozhe Wu, Weinong Fu, Yulong Liu, Yunchong Wang, Peihuang Zeng
January 7, 2019 (v1)
Keywords: decouple control, dual-stator, electric vehicles (EVs), flux-modulated, vector control (VC)
This paper presents the control strategies for a novel dual-stator flux-modulated (DSFM) motor for application in electric vehicles (EVs). The DSFM motor can be applied to EVs because of its simple winding structure, high reliability, and its use of two stators and rotating modulation steels in the air gap. Moreover, it outperforms conventional brushless doubly-fed machines in terms of control performance. Two stator-current-oriented vector controls with different excitation in the primary winding, direct and alternating current excitation, are designed, simulated, and evaluated on a custom-made DSFM prototype allowing the decoupled control of torque. The stable speed response and available current characteristics strongly validate the feasibility of the two control methods. Furthermore, the proposed control methods can be employed in other applications of flux-modulated motors.
Smart Monitoring Embedded Service for Energy-Efficient and Sustainable Management in Data Centers
Diego Marcos-Jorquera, Virgilio Gilart-Iglesias, Francisco José Mora-Gimeno, Juan Antonio Gil-Martínez-Abarca
January 7, 2019 (v1)
Keywords: embedded systems, energy-efficient networks, monitoring energy-consumption, service oriented architecture, sustainable network
Information technologies (IT) currently represent 2% of CO₂ emissions. In recent years, a wide variety of IT solutions have been proposed, focused on increasing the energy efficiency of network data centers. Monitoring is one of the fundamental pillars of these systems, providing the information necessary for adequate decision making. However, today’s monitoring systems (MSs) are partial, specific and highly coupled solutions. This study proposes a model for monitoring data centers that serves as a basis for energy saving systems, offered as a value-added service embedded in a device with low cost and power consumption. The proposal is general in nature, comprehensive, scalable and focused on heterogeneous environments, and it allows quick adaptation to the needs of changing and dynamic environments. Further, a prototype of the system has been implemented in several devices, which has allowed validation of the proposal in addition to identification of the minimum hardware profile requi... [more]
Implementation of Rapid Prototyping Tools for Power Loss and Cost Minimization of DC-DC Converters
Amruta V. Kulkarni, Weiqiang Chen, Ali M. Bazzi
January 7, 2019 (v1)
Subject: Other
Keywords: DC-DC converters, design methodology, design optimization, rapid prototyping, user centered design, user interface
In this paper, power loss and cost models of power electronic converters based on converter ratings and datasheet information are presented. These models aid in creating rapid prototypes which facilitate the component selection process. Through rapid prototyping, users can estimate power loss and cost which are essential in design decisions. The proposed approach treats main power electronic components of a converter as building blocks that can be arranged to obtain multiple topologies to facilitate rapid prototyping. In order to get system-level power loss and cost models, two processes are implemented. The first process automatically provides minimum power loss or cost estimates and identifies components for specific applications and ratings; the second process estimates power losses and costs of each component of interest as well as the whole system. Two examples are used to illustrate the proposed approaches—boost and buck converters in continuous conduction mode. Achieved cost and... [more]
Experimental Study of Crack Initiation and Extension Induced by Hydraulic Fracturing in a Tree-Type Borehole Array
Yiyu Lu, Shaojie Zuo, Zhaolong Ge, Songqiang Xiao, Yugang Cheng
January 7, 2019 (v1)
Subject: Other
Keywords: acoustic emission, coal bed methane, coal permeability, hydraulic fracturing, tree-type borehole array
High-pressure hydraulic fracturing technology in coal and coal bed methane mines can lead to roof and floor damage, and fracture initiation disorder that leads to a “blank area”, and other issues. A new method of hydraulic fracturing is proposed to increase the homogeneous permeability of coal in underground coalmines. Numerical and other simulation tests for different forms of a tree-type, branched borehole model are presented. The results show that the branched array causes cracks to initiate from the bottom of the array, and these extend along the direction of the adjacent boreholes. Generally, as the number of branched boreholes increases, the coal seam fracture network also increase, improving the distribution of the fracture network, making the fracturing effect better. The branched boreholes appear to reduce initiation pressure and, with increasing branches, the initiation pressure decreases. A model with four tree-type, branched boreholes leads to a reduction in initiation pres... [more]
A Review of Wave-to-Wire Models for Wave Energy Converters
Markel Penalba, John V. Ringwood
January 7, 2019 (v1)
Keywords: electric generator, electricity network, hydraulic system, hydrodynamic model, power converters, Wave Energy, wave resource, wave-to-wire model
Control of wave energy converters (WECs) has been very often limited to hydrodynamic control to absorb the maximum energy possible from ocean waves. This generally ignores or significantly simplifies the performance of real power take-off (PTO) systems. However, including all the required dynamics and constraints in the control problem may considerably vary the control strategy and the power output. Therefore, this paper considers the incorporation into the model of all the conversion stages from ocean waves to the electricity network, referred to as wave-to-wire (W2W) models, and identifies the necessary components and their dynamics and constraints, including grid constraints. In addition, the paper identifies different control inputs for the different components of the PTO system and how these inputs are articulated to the dynamics of the system. Examples of pneumatic, hydraulic, mechanical or magnetic transmission systems driving a rotary electrical generator, and linear electric g... [more]
Laminar Flame Characteristics of C1⁻C5 Primary Alcohol-Isooctane Blends at Elevated Temperature
Qianqian Li, Wu Jin, Zuohua Huang
January 7, 2019 (v1)
Keywords: empirical correlation, isooctane, laminar flame speed, Markstein length, oxygen content, primary alcohol
The laminar combustion characteristics of blends of isooctane and C1⁻C5 primary alcohols (i.e., methanol, ethanol, n-propanol, n-butanol and n-pentanol) were investigated using the spherical expanding flame methodology in a constant volume chamber at various equivalence ratios and volume fractions of alcohol. The stretch effect was removed using the nonlinear methodology. The results indicate that the laminar flame speeds of alcohol-isooctane blends increase monotonously with the increasing volume fraction of alcohol. Among the five alcohols, the addition of methanol is identified to be the most effective in enhancing laminar flame speed. The addition of ethanol results in an approximately equivalent laminar flame speed enhancement rate as those of n-propanol, n-butanol and n-pentanol at ratios of 0.8 and 1.5, and a higher rate at 1.0 and 1.2. An empirical correlation is provided to describe the laminar flame speed variation with the volume fraction of alcohol. Meanwhile, the laminar f... [more]
Application of Scaling-Law and CFD Modeling to Hydrodynamics of Circulating Biomass Fluidized Bed Gasifier
Mazda Biglari, Hui Liu, Ali Elkamel, Ali Lohi
January 7, 2019 (v1)
Keywords: computation fluid dynamics, fluidized bed, scaling-law
Two modeling approaches, the scaling-law and CFD (Computational Fluid Dynamics) approaches, are presented in this paper. To save on experimental cost of the pilot plant, the scaling-law approach as a low-computational-cost method was adopted and a small scale column operating under ambient temperature and pressure was built. A series of laboratory tests and computer simulations were carried out to evaluate the hydrodynamic characteristics of a pilot fluidized-bed biomass gasifier. In the small scale column solids were fluidized. The pressure and other hydrodynamic properties were monitored for the validation of the scaling-law application. In addition to the scaling-law modeling method, the CFD approach was presented to simulate the gas-particle system in the small column. 2D CFD models were developed to simulate the hydrodynamic regime. The simulation results were validated with the experimental data from the small column. It was proved that the CFD model was able to accurately predic... [more]
Inductive Power Transfer Systems for Bus-Stop-Powered Electric Vehicles
Chung-Chuan Hou, Kuei-Yuan Chang
January 7, 2019 (v1)
Keywords: bus-stop-powered, electric vehicles, inductive power transfer
This study presents an inductive power transfer (IPT) system for electric vehicles (EVs) based on EE-shaped ferrite cores. The issues of the IPT system such as efficiency, air gap, displacement, dislocation, and motion are discussed. Furthermore, finite element analysis software is utilized to simulate the IPT system operated under large air gap conditions. Simulation and measurement results are presented to validate the performance of the proposed scheme and meet the requirements for bus-stop-powered EVs.
Zinc Porphyrins Possessing Three p-Carboxyphenyl Groups: Effect of the Donor Strength of Push-Groups on the Efficiency of Dye Sensitized Solar Cells
Ram B. Ambre, Sandeep B. Mane, Chen-Hsiung Hung
January 7, 2019 (v1)
Subject: Materials
Keywords: dye sensitized solar cell (DSSC), porphyrin sensitizer
Zinc porphyrins decorated with three p-carboxyphenyl anchoring groups and various “push” substituents of varied electron-donating strengths were prepared in good yields by facile and straightforward ways. The effect of electron-donating strength of the donor molecules on the overall power conversion efficiency was evaluated with the help of photophysical, electrochemical, photovoltaic spectroscopy and quantum chemical calculations. It is observed from the photophysical and Infrared (IR) spectroscopic data that multi-anchoring dyes are more stable and bind more strongly to the TiO₂ surface than their one-anchor counterparts. The properties like a three-step synthesis, high overall yields, possible mass production on a gram-scale and strong binding affinities with TiO₂ surfaces make them a suitable choice for commercial applications. Zn₁NH₃A, with electron donating and anti-aggregation characteristics, achieved the highest efficiency of 6.50%.
Progress of the Plasma Centerpost for the PROTO-SPHERA Spherical Tokamak
Alessandro Lampasi, Giuseppe Maffia, Franco Alladio, Luca Boncagni, Federica Causa, Edmondo Giovannozzi, Luigi Andrea Grosso, Alessandro Mancuso, Paolo Micozzi, Valerio Piergotti, Giuliano Rocchi, Alessandro Sibio, Benedetto Tilia, Vincenzo Zanza
January 7, 2019 (v1)
Keywords: nuclear fusion, pinch, plasma physics, power converters and inverters, power plants, power supply, spherical tokamak, sustainable energy sources
Plasma properties can be useful in a wide spectrum of applications. Experimental projects on controlled nuclear fusion are the most challenging of these applications and, at the same time, the best way to approach plasma science. Since nuclear fusion reactors can ensure a large-scale, safe, environmentally-friendly and virtually inexhaustible source of energy, several fusion-oriented megaprojects and innovative companies are appearing all over the world. PROTO-SPHERA (Spherical Plasma for HElicity Relaxation Assessment) is the first plasma project with a simply connected configuration, namely not requiring additional objects inside the plasma volume. This is obtained by a plasma arc, shaped as a screw pinch, acting as the centerpost of a spherical torus with minimal aspect ratio. Due to its intrinsic physical, engineering and economic advantages, this new approach is attractive also on an industrial scale and with several developments that still needs to be explored. This paper present... [more]
Curtailment in a Highly Renewable Power System and Its Effect on Capacity Factors
Alexander Kies, Bruno U. Schyska, Lueder von Bremen
January 7, 2019 (v1)
Keywords: capacity factor, effective capacity factor, energy system modeling, German power system, renewable energy systems, renewable site assessment
The capacity factor of a power plant is the ratio of generation over its potential generation. It is an important measure to describe wind and solar resources. However, the fluctuating nature of renewable power generation makes it difficult to integrate all generation at times. Whenever generation exceeds the load, curtailment or storage of energy is required. With increasing renewable shares in the power system, the level of curtailment will further increase. In this work, the influence of the curtailment on the capacity factors for a highly renewable German power system is studied. An effective capacity factor is introduced, and the implications for the distribution of renewable power plants are discussed. Three years of highly-resolved weather data were used to model wind and solar power generation. Together with historical load data and a transmission model, a possible future German power system was simulated. It is shown that effective capacity factors for unlimited transmission a... [more]
Combined Two-Stage Stochastic Programming and Receding Horizon Control Strategy for Microgrid Energy Management Considering Uncertainty
Zhongwen Li, Chuanzhi Zang, Peng Zeng, Haibin Yu
January 7, 2019 (v1)
Keywords: energy management, microgrid, recording horizon control, stochastic programming, uncertainty
Microgrids (MGs) are presented as a cornerstone of smart grids. With the potential to integrate intermittent renewable energy sources (RES) in a flexible and environmental way, the MG concept has gained even more attention. Due to the randomness of RES, load, and electricity price in MG, the forecast errors of MGs will affect the performance of the power scheduling and the operating cost of an MG. In this paper, a combined stochastic programming and receding horizon control (SPRHC) strategy is proposed for microgrid energy management under uncertainty, which combines the advantages of two-stage stochastic programming (SP) and receding horizon control (RHC) strategy. With an SP strategy, a scheduling plan can be derived that minimizes the risk of uncertainty by involving the uncertainty of MG in the optimization model. With an RHC strategy, the uncertainty within the MG can be further compensated through a feedback mechanism with the lately updated forecast information. In our approach,... [more]
Study of Coal Burst Source Locations in the Velenje Colliery
Goran Vižintin, Maja Kocjančič, Milivoj Vulić
January 7, 2019 (v1)
Subject: Energy Policy
Keywords: coal burst, mining-induced seismicity, rockburst, Velenje coal mine (VCM)
The Velenje coal mine (VCM) is situated on the largest Slovenian coal deposit and in one of the thickest layers of coal known in the world. The thickness of the coal layer causes problems for the efficiency of extraction, since the majority of mining operations is within the coal layer. The selected longwall coal mining method with specific geometry, increasing depth of excavations, changes in stress state and naturally given geomechanical properties of rocks induce seismic events. Induced seismic events can be caused by caving processes, blasting or bursts of coal or the surrounding rock. For 2.5D visualization, data of excavations, ash content and calorific value of coal samples, hanging wall and footwall occurrence, subsidence of the surface and coal burst source locations were collected. Data and interpolation methods available in software package Surfer®12 were statistically analyzed and a Kriging (KRG) interpolation method was chosen. As a result 2.5D visualizations of coal burst... [more]
A Holistic Approach for Addressing the Issue of Effective Technology Transfer in the Frame of Climate Change
Charikleia Karakosta
January 7, 2019 (v1)
Subject: Energy Policy
Keywords: climate change, decision support, developing world, econometria, energy sector, multicriteria analysis, sustainable development, technology transfer
Climate change policy and sustainable development issues and goals are closely intertwined. Recognizing the dual relationship between sustainable development and climate change points to a need for the exploration of actions that jointly address sustainable development and climate change. Technology transfer is considered an issue with growing interest worldwide and has been recognized as the key in supporting countries to achieve sustainable development, while addressing climate change challenges. This study presents an integrated decision support methodological framework for the formulation and evaluation of activities to promote technology transfer, as well as the provision of clear recommendations and strategies for framing specific policy in the context of climate change. The philosophy of the proposed approach, under the name: assess-identify-define (AID), consists of three components, where each one focuses on a particular problem. The methodology is integrated using appropriate... [more]
High Pressure Oxydesulphurisation of Coal—Effect of Oxidizing Agent, Solvent, Shear and Agitator Configuration
Moinuddin Ghauri, Khurram Shahzad, Abrar Inayat, Zulfiqar Ali, Waqar Ali Khan, Javaid Akhtar, Keith R. Cliffe
January 7, 2019 (v1)
Keywords: Coal, organic sulphur, oxydesulphurisation, pyritic sulphur
The ambient temperature high pressure oxydesulphurisation technique was investigated to reduce the sulphur content. Prince of Wales coal was chosen for this study. The focus of the study was to investigate the reduction of both pyritic and organic sulphur while changing the KMnO₄/Coal ratio, agitation speed, agitator configuration, and shear. The effect of different concentrations of acetone as a solvent and effect of particle size on the sulphur removal was also studied by a series of experimental runs at ambient temperature. Heating value recovery was found to be increased with the decreased KMnO₄/Coal ratio and with decreased acetone concentration. It was found that sulphur removal was enhanced with the increase in shear using a turbine impeller. The effect of particle size was more significant on the pyritic sulphur removal as compared to the organic sulphur removal while heating value recovery was found to increase with decreased desulphurization tome for both, under atmospheric a... [more]
Hydropower Production in Future Climate Scenarios; the Case for the Zambezi River
Byman H. Hamududu, Ånund Killingtveit
January 7, 2019 (v1)
Subject: Energy Policy
Keywords: Africa, climate change, hydrology, hydropower production, impacts, Malawi, Mozambique, water resources, Zambezi, Zambia, Zimbabwe
Climate change remains a threat to water resources projects in southern Africa where impacts resulting from changes in climate are projected to be negative and worse than in most other regions of the world. This work presents an assessment of the impacts of climate change on water resources and hydropower production potential in the Zambezi River Basin. Future climate scenarios projected through the five General Circulation Model (GCM) outputs are used as input in the impact assessment. The future projected climate scenarios are downscaled to find local and regional changes, and used in the Hydrologiska Byråns Vattenbalansavdelning (HBV) hydrological model to assess climate change impacts on water resources in the river basin. According to the simulations, air temperature and potential evaporation are projected to increase, while rainfall is projected to decrease. The Zambezi hydropower system is likely to be affected negatively as a result of future climate changes. Increasing air tem... [more]
Analysis and Controller Design of a Universal Bidirectional DC-DC Converter
Kou-Bin Liu, Chen-Yao Liu, Yi-Hua Liu, Yuan-Chen Chien, Bao-Sheng Wang, Yong-Seng Wong
January 7, 2019 (v1)
Keywords: adaptive phase-shift control, bidirectional buck–boost DC-DC converter, zero voltage switching
In this paper, first the operating principles of a non-isolated universal bidirectional DC-DC converter are studied and analyzed. The presented power converter is capable of operating in all power transferring directions in buck/boost modes. Zero voltage switching can be achieved for all the power switches through proper modulation strategy design, therefore, the presented converter can achieve high efficiency. To further improve the efficiency, the relationship between the phase-shift angle and the overall system efficiency is analyzed in detail, an adaptive phase-shift (APS) control method which determines the phase-shift value between gating signals according to the load level is then proposed. As the modulation strategy is a software-based solution, there is no requirement for additional circuits, therefore, it can be implemented easily and instability and noise susceptibility problems can be reduced. To validate the correctness and the effectiveness of the proposed method, a 300 W... [more]
Greening the NetFPGA Reference Router
Feng Guo, Xiaojun Wang, Mei Song, Yifei Wei, Olga Ormond, Martin Collier
January 7, 2019 (v1)
Keywords: dynamic frequency scaling, energy proportional routing, green networking
Energy efficiency is an important criterion in the design of next generation networks for both economic and environmental concerns. This paper presents an energy-efficient router that is able to dynamically adapt its routing capability in response to real-time traffic load, achieving energy proportional routing. The NetFPGA reference router, which operates at one of two frequencies (125 MHz or 62.5 MHz), requires a board reset to switch frequencies. We have modified the reference router to allow dynamic switching among five operating frequencies. Experiments with real traces indicate that, compared to the reference router, a 10% power reduction can be achieved through dynamic frequency scaling. When the router is further modified to support green traffic engineering and Ethernet port shut-down, power consumption can be reduced by 46% while maintaining the required quality of service. This allows the router to meet the instantaneous performance requirements while minimizing power dissip... [more]
Flexible Grouping for Enhanced Energy Utilization Efficiency in Battery Energy Storage Systems
Weiping Diao, Jiuchun Jiang, Hui Liang, Caiping Zhang, Yan Jiang, Leyi Wang, Biqiang Mu
January 7, 2019 (v1)
Keywords: battery, converter efficiency, energy utilization efficiency, flexible group
As a critical subsystem in electric vehicles and smart grids, a battery energy storage system plays an essential role in enhancement of reliable operation and system performance. In such applications, a battery energy storage system is required to provide high energy utilization efficiency, as well as reliability. However, capacity inconsistency of batteries affects energy utilization efficiency dramatically; and the situation becomes more severe after hundreds of cycles because battery capacities change randomly due to non-uniform aging. Capacity mismatch can be solved by decomposing a cluster of batteries in series into several low voltage battery packs. This paper introduces a new analysis method to optimize energy utilization efficiency by finding the best number of batteries in a pack, based on capacity distribution, order statistics, central limit theorem, and converter efficiency. Considering both battery energy utilization and power electronics efficiency, it establishes that t... [more]
Performance Analysis of a Reciprocating Piston Expander and a Plate Type Exhaust Gas Recirculation Boiler in a Water-Based Rankine Cycle for Heat Recovery from a Heavy Duty Diesel Engine
Gunnar Latz, Olof Erlandsson, Thomas Skåre, Arnaud Contet, Sven Andersson, Karin Munch
January 7, 2019 (v1)
Keywords: piston expander, Rankine cycle, waste-heat recovery (WHR)
The exhaust gas in an internal combustion engine provides favorable conditions for a waste-heat recovery (WHR) system. The highest potential is achieved by the Rankine cycle as a heat recovery technology. There are only few experimental studies that investigate full-scale systems using water-based working fluids and their effects on the performance and operation of a Rankine cycle heat recovery system. This paper discusses experimental results and practical challenges with a WHR system when utilizing heat from the exhaust gas recirculation system of a truck engine. The results showed that the boiler’s pinch point necessitated trade-offs between maintaining adequate boiling pressure while achieving acceptable cooling of the EGR and superheating of the water. The expander used in the system had a geometric compression ratio of 21 together with a steam outlet timing that caused high re-compression. Inlet pressures of up to 30 bar were therefore required for a stable expander power output.... [more]
Design, Simulation and Experimental Investigation of a Solar System Based on PV Panels and PVT Collectors
Annamaria Buonomano, Francesco Calise, Maria Vicidomini
January 7, 2019 (v1)
Keywords: dynamic simulation, experimental, PV panes, PVT collectors
This paper presents numerical and experimental analyses aimed at evaluating the technical and economic feasibility of photovoltaic/thermal (PVT) collectors. An experimental setup was purposely designed and constructed in order to compare the electrical performance of a PVT solar field with the one achieved by an identical solar field consisting of conventional photovoltaic (PV) panels. The experimental analysis also aims at evaluating the potential advantages of PVT vs. PV in terms of enhancement of electrical efficiency and thermal energy production. The installed experimental set-up includes four flat polycrystalline silicon PV panels and four flat unglazed polycrystalline silicon PVT collectors. The total electrical power and area of the solar field are 2 kWe and 13 m², respectively. The experimental set-up is currently installed at the company AV Project Ltd., located in Avellino (Italy). This study also analyzes the system from a numerical point of view, including a thermo-economi... [more]
Implementation and Validation of a Self-Consumption Maximization Energy Management Strategy in a Vanadium Redox Flow BIPV Demonstrator
Luis Fialho, Tomás Fartaria, Luis Narvarte, Manuel Collares Pereira
January 7, 2019 (v1)
Keywords: building integrated photovoltaics (BIPV), energy management strategy, real-scale battery, self-consumption maximization, vanadium redox flow battery
This paper presents the results of the implementation of a self-consumption maximization strategy tested in a real-scale Vanadium Redox Flow Battery (VRFB) (5 kW, 60 kWh) and Building Integrated Photovoltaics (BIPV) demonstrator (6.74 kWp). The tested energy management strategy aims to maximize the consumption of energy generated by a BIPV system through the usage of a battery. Whenever possible, the residual load is either stored in the battery to be used later or is supplied by the energy stored previously. The strategy was tested over seven days in a real-scale VRF battery to assess the validity of this battery to implement BIPV-focused energy management strategies. The results show that it was possible to obtain a self-consumption ratio of 100.0%, and that 75.6% of the energy consumed was provided by PV power. The VRFB was able to perform the strategy, although it was noticed that the available power (either to charge or discharge) varied with the state of charge.
An Integrated Multifunctional Bidirectional AC/DC and DC/DC Converter for Electric Vehicles Applications
Liwen Pan, Chengning Zhang
January 7, 2019 (v1)
Subject: Other
Keywords: AC/DC converter, DC/DC converter, electric vehicle, integrated bidirectional charger
This paper presents an on-board vehicular battery charger that integrates bidirectional AC/DC converter and DC/DC converter to achieve high power density for application in electric vehicles (EVs). The integrated charger is able to transfer electrical energy between the battery pack and the electric traction system and to function as an AC/DC battery charger. The integrated charger topology is presented and the design of passive components is discussed. The control schemes are developed for motor drive system and battery-charging system with a power pulsation reduction circuit. Simulation results in MATLAB/Simulink and experiments on a 30-kW motor drive and 3.3-kW AC/DC charging prototype validate the performance of the proposed technology. In addition, power losses, efficiency comparison and thermal stress for the integrated charger are illustrated. The results of the analyses show the validity of the advanced integrated charger for electric vehicles.
Super-Twisting Differentiator-Based High Order Sliding Mode Voltage Control Design for DC-DC Buck Converters
Yigeng Huangfu, Shengrong Zhuo, Akshay Kumar Rathore, Elena Breaz, Babak Nahid-Mobarakeh, Fei Gao
January 7, 2019 (v1)
Keywords: DC-DC converter, high-order sliding mode, robust control, sensor-less
This paper aims to focus on the smooth output of DC-DC buck converters in wireless power transfer systems under input perturbations and load disturbances using the high-order sliding mode controller (HOSM) and HOSM with super-twisting differentiator (HOSM + STD). The proposed control approach needs only measurement of converter output voltage. Theoretical analysis and design procedures, as well as the super-twisting differentiator of the proposed controller are presented in detail with the prescribed convergence law of high-order sliding modes. Comparisons of both simulation and experimental results among conventional proportional-integral (PI) control, traditional sliding mode control (SMC), HOSM and HOSM + STD under various test conditions such as steady state, input voltage perturbations and output load disturbances, are presented and discussed. The results demonstrate and validate the effectiveness and robustness of the proposed control method.
Showing records 196 to 220 of 220. [First] Page: 1 5 6 7 8 9 Last
Change year: 2018 | 2019
Change month: January | February | March | April | May | June | July | August | September | October