A Single-Stage LED Driver Based on ZCDS Class-E Current-Driven Rectifier as a PFC for Street-Lighting Applications

This paper presents a light-emitting diode (LED) driver for street-lighting applications that uses a resonant rectifier as a power-factor corrector (PFC). The PFC semistage is based on a zero-current and zero-derivative-switching (ZCDS) Class-E current-driven rectifier, and the LED driver semistage is based on a zero-voltage-switching (ZVS) Class-D LLC resonant converter that is integrated into a single-stage topology. To increase the conduction angle of the bridge-rectifier diodes current and to decrease the current harmonics that are injected in the utility line, the ZCDS Class-E rectifier is placed between the bridge-rectifier and a dc-link capacitor. The ZCDS Class-E rectifieris driven by a high-frequency current source, which is obtained from a square-wave output voltage of the ZVS Class-D LLC resonant converter using a matching network. Additionally, the proposed converter has a soft-switching characteristic that reduces switching losses and switching noise. A prototype for a 150-W LED street light has been developed and tested to evaluate the performance of the proposed approach. The proposed LED driver had a high efficiency (>91%), a high PF (>0.99), and a low total harmonic distortion (THD i <; 8%) under variation of the utility-line input voltage from 180 to 250 V rms . These experimental results demonstrate the feasibility of the proposed LED scheme

Optimal Operation of Distributed Generations Considering Demand Response in a Microgrid Using GWO Algorithm

The widespread penetration of distributed energy sources and theuse of load response programs, especially in a microgrid, have caused manypower system issues, such as control and operation of these networks, tobe affected. The control and operation of many small-distributed generationunits with different performance characteristics create another challenge forthe safe and efficient operation of the microgrid. In this paper, the optimumoperation of distributed generation resources and heat and power storage ina microgrid, was performed based on real-time pricing through the proposedgray wolf optimization (GWO) algorithm to reduce the energy supply costwith the microgrid. Distributed generation resources such as solar panels,diesel generators with battery storage, and boiler thermal resources withthermal storage were used in the studied microgrid. Also, a combined heatand power (CHP) unit was used to produce thermal and electrical energysimultaneously. In the simulations, in addition to the gray wolf algorithm,some optimization algorithms have also been used. Then the results of 20runs for each algorithm confirmed the high accuracy of the proposed GWOalgorithm. The results of the simulations indicated that the CHP energyresources must be managed to have a minimum cost of energy supply in themicrogrid, considering the demand response program

Hybridizing Technology Management and Knowledge Management to Spur Innovation: A System Dynamics Approach

The purpose of this research is to identify the drivers of innovativeness in a furniture manufacturing company. The scenario is the business environment where the hybridization of Technology Management (TM) and Knowledge Management (KM) is operative to promote innovation. The elements of the Technology Acceptance Model (TAM) and Socialization-Externalization-Internalization-Externalization (SECI) Model of KM have been modeled and used for simulation for the identification of the role played by the factors influencing the furniture design information conversion rate. The research follows the case study method to research as it draws data from a single company. Data from a multinational furniture manufacturing company that has over 10,000 products and operates in 24 countries have been used for simulation purposes. Results have shown that among the five factors that influence information conversion rate, the company should focus on correction efficiency and calculation efficiency enhancement if the aim is to maximize product and process innovations; and enhance contextualization efficiency if the priority is immediate results of innovativeness improvement. The results have also shown that about 615 innovative products and processes can be produced in six months by improving the correction efficiency to 80%. The theoretical implication of the study is in the form of a model which can be used by innovative companies to identify the critical factors that influence innovativeness, and the practical implications are in the form of suggestions to the managers of the furniture manufacturing company to enhance their innovativeness so as to gain competitive advantage in business

Conception d'une source hybride utilisant une pile à combustible et des supercondensateurs

The design and testing of a purely supercapacitor energy storage device as auxiliary powersource in electrical vehicle applications having a PEM fuel cell as main source are presented.The two control strategies are explained. The control algorithms are that fuel cell is simplyoperating in almost steady state conditions in order to lessen the mechanical stresses of fuelcell and to ensure a good synchronization between fuel flow and fuel cell current.Supercapacitors are functioning during absence of energy from fuel cell, transient energydelivery or transient energy recovery.The system utilizes two modules of SAFT supercapacitive storage device. This device isconnected to a 42 V DC bus by a 2-quadrant dc/dc converter, and fuel cell is connected to thedc bus by a boost converter. The system structure is realized by analogical current loops anddigital control (dSPACE) for voltage loops and estimation algorithms. Experimental resultswith a 500 W PEM fuel cell point out the slow dynamics naturally of fuel cell because ofthermodynamic and mechanical operation, and also substantiate that the supercapacitors canimprove dynamics and power conditioning for automotive electrical system.L'étude, le dimensionnement et le test d'un dispositif de stockage d'énergie, à base desupercondensateurs, destiné à fonctionner dans un véhicule à pile à combustible sontprésentés dans cette thèse. Deux modes de commande sont détaillés. Leur but est de permettreun fonctionnement en quasi-statique de la pile à combustible afin de limiter les contraintesmécaniques sur la pile en accordant les débits de gaz à la demande en courant. Lessupercapacités interviennent lors du non-fonctionnement de la pile, lors de régimestransitoires ou de régimes de récupération.Le dispositif développé utilise deux modules de supercapacités SAFT. Il est connecté à un buscontinu 42 V par un convertisseur continu-continu deux quadrants, la pile à combustible étantconnectée au bus continu par un convertisseur élévateur. Le contrôle des courants est réaliséde manière analogique. Le contrôle des tensions et les algorithmes d'estimation utilisent unecarte numérique dSPACE. Les résultats expérimentaux présentés, obtenus avec une pile de500 W, ont souligné la lenteur naturelle des réponses de la pile à combustible et l'apport dessupercapacités pour des applications automobiles. Celles-ci améliorent grandement ladynamique et le contrôle énergétique du système

Differential Flatness Based-Control Strategy of a Two-Port Bidirectional Supercapacitor Converter for Hydrogen Mobility Applications

This article is focused on an original control approach applied to a transportation system that includes a polymer electrolyte membrane fuel cell (PEMFC) as the main energy source and supercapacitors (SC) as the energy storage backup. To interface the SC with the DC bus of the embedded network, a two-port bidirectional DC-DC converter was used. To control the system and ensure its stability, a reduced-order mathematical model of the network was developed through a nonlinear control approach employing a differential flatness algorithm, which is an attractive and efficient solution to make the system stable by overcoming the dynamic issues generally met in the power electronics networks of transportation systems. The design and tuning of the system control were not linked with the equilibrium point at which the interactions between the PEMFC main source, the SC energy storage device, and the loads are taken into consideration by the proposed control law. Besides this, high dynamics in the load power rejection were accomplished, which is the main contribution of this article. To verify the effectiveness of the developed control law, a small-scale experimental test rig was realized in the laboratory and the control laws were implemented in a dSPACE 1103 controller board. The experimental tests were performed with a 1 kW PEMFC source and a 250 F 32 V SC module as an energy storage backup. Lastly, the performances of the proposed control strategy were validated based on real experimental results measured during driving cycles, including motoring mode, ride-though, and regenerative braking mode

Multi-Objective Energy Management Strategy for PV/FC Hybrid Power Systems

In this paper, a new control of the DC–DC power converter that interfaces the fuel cell (FC) system with the DC bus of the photovoltaic (PV) power system is proposed to increase the battery lifespan by its operating in charge-sustained mode. Thus, the variability of the PV power and the load demand is compensated by the FC power generated considering the power flows balance on the DC bus. During peak PV power, if the PV power exceeds the load demand, then the excess power on the DC bus will power an electrolyzer. The FC system operation as a backup energy source is optimized using a new fuel economy strategy proposed for fueling regulators. The fuel optimization function considers the fuel efficiency and electrical efficiency of the FC system to maximize fuel economy. The fuel economy obtained in the scenarios considered in this study is compared with reference strategies reported in the literature. For example, under scenarios considered in this paper, the fuel economy is between 4.82–20.71% and 1.64–3.34% compared to a commercial strategy based on static feed-forward (sFF) control and an advanced strategy recently proposed in the literature, respectively

Energy Efficiency and Fuel Economy of a Fuel Cell/Renewable Energy Sources Hybrid Power System with the Load-Following Control of the Fueling Regulators

Two Hybrid Power System (HPS) topologies are proposed in this paper based on the Renewable Energy Sources (RESs) and a Fuel Cell (FC) system-based backup energy source. Photovoltaic arrays and wind turbines are modeled as RESs power flow. Hydrogen and air needed for FC stack to generate the power requested by the load are achieved through the Load-Following control loop. This control loop will regulate the fueling flow rate to load level. A real-time optimization strategy for RES/FC HPS based on Extremum Seeking Control will find the Maximum Efficiency Point or best fuel economy point by control of the boost converter. Therefore, two HPS configurations and associated strategies based on Load-Following and optimization loops of the fueling regulators were studied here and compared using the following performance indicators: the FC net power generated on the DC bus, the FC energy efficiency, the fuel consumption efficiency, and the total fuel consumption. An increase in the FC system&rsquo;s electrical efficiency and fuel economy of up to 2% and 12% respectively has been obtained using the proposed optimization strategies compared with a baseline strategy

Conception d'une source hybride utilisant une pile à combustible et des supercondensateurs

L'étude, le dimensionnement et le test d'un dispositif de stockage d'énergie destiné à fonctionner dans un véhicule à pile à combustible sont présentés. Deux modes de commande sont détaillés afin d'opérer en quasi-statique et de limiter les contraintes mécaniques en accordant les débits de gaz à la demande en courant. Les supercapacités interviennent lors du non fonctionnement de la pile, lors de régimes transitoires ou de régimes de récupération. Le dispositif développé utilise deux modules de supercapacités connectés à un bus continu par un convertisseur dc-dc. Le contrôle des courants est réalisé de manière analogique. Le contrôle des tensions et les algorithmes d'estimation utilisent une carte numérique. Les résultats expérimentaux présentés, obtenus avec une pile de 500 W, ont souligné la lenteur de la pile à combustible et l'apport des supercapacités pour des applications automobiles. Celles-ci améliorent grandement la dynamique et le contrôle énergétique du systèmeThe design and testing of a purely supercapacitor energy storage device as auxiliary power source in electrical vehicle applications having a PEM fuel cell as main source are presented. Two control strategies are explained to operate in almost steady state conditions in order to lessen the mechanical stresses of fuel cell and to ensure a good synchronization between fuel flow and fuel cell current. Supercapacitors are functioning during absence of energy from fuel cell, transient energy delivery or transient energy recovery. The system utilizes two modules of supercapacitive storage device connected to the DC bus by a 2-quadrant dc/dc converter. The system structure is realized by analogical current loops and digital control for voltage loops and estimation algorithms. Experimental results with a 500 W PEM fuel cell point out the slow dynamics of fuel cell, and also substantiate that the supercapacitors can improve dynamics and power conditioning for automotive electrical systemNANCY/VANDOEUVRE-INPL (545472102) / SudocSudocFranceF

The benefits of hybridization

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