Academic literature on the topic 'DC-AC CONVERSIONS'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'DC-AC CONVERSIONS.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "DC-AC CONVERSIONS"
1
Yang, Da Wei, Jian Hua Yang, Fei Lin, Jian Su, and Hai Tao Liu. "Application and Selection to AC and DC Voltage Grades for Microgrids." Advanced Materials Research 791-793 (September 2013): 1876–79. http://dx.doi.org/10.4028/www.scientific.net/amr.791-793.1876.
Full textAbstract:
Distributed resources and microgrids may be designed for power supply in some area. AC-DC or DC-AC conversions are required in microgrids because of DC distributed resources, e.g. photovoltaic arrays. In this paper some factors are considered for determining the voltage grades of microgrids, both AC grid and DC grid, according to comprehensive analysis of microgrid design and operation. The factors include microgrid or distributed resource capacity, efficiency, cost, safety and so on. The line length, microgrid capacity and economic impacts are taken into account for selecting the voltage grade to connect the microgrid into the distribution system. Further, suitable AC and DC voltage grades are selected for residential and commercial application with some microgrid cases.
2
Szekely, Norbert Csaba, Sorin Ionut Salcu, Vasile Mihai Suciu, Lucian Nicolae Pintilie, Gheorghe Ioan Fasola, and Petre Dorel Teodosescu. "Power Factor Correction Application Based on Independent Double-Boost Interleaved Converter (IDBIC)." Applied Sciences 12, no. 14 (July 18, 2022): 7209. http://dx.doi.org/10.3390/app12147209.
Full textAbstract:
In this paper, a Power Factor Correction (PFC) application, based on the novel power stage topology named Independent Double-Boost Interleaved Converter (IDBIC), has been analyzed. The novelty of the proposed PFC rectifier is based on the sum of capabilities, such as supplying three independent output voltage levels with interleaved operation at the input and high voltage gain. The hardware used within this application consists of an AC input L-C-L filter, a single-phase bridge rectifier, the IDBIC power stage, output capacitors group and a group of variable high-power rheostats (resistors) group as DC load. The main purpose of the carried study was to highlight the advantages and disadvantages of the novel power stage topology in the context of a green and modern AC to DC conversion solution. Nowadays, a high level of the efficiency and power factor have become a mandatory feature for the AC to DC conversion solutions to satisfy the international electrical standards. Thus, considering the modern electrical standards and recommendations, the current study tries to better depict the working steps and principles of the modern power stage topology within an AC to DC conversion application. The behavior of the considered power stage described in different detailed working steps (such as the Discontinuous Conduction Mode and Continuous Conduction Mode) may help understand how the energy conversions process of AC to DC becomes more efficient. The high output voltage gain of the considered power stage is the key feature in the Power Factor Correction process. With such a feature, the AC to DC conversion solution/application can also operate at lower input AC voltages (such as 90 [V] and 110 [V]). The proposed solution can be successfully used in the electric vehicle (automotive field) and high-power electrical traction (e.g., trains, high power electrical machines and drives). The same solution can also be used successfully in fast battery charging applications and chemical electrolysis processes.
3
Barui, T. K., S. Goswami, and D. Mondal. "Design of Digitally Controlled DC-DC Boost Converter for the Operation in DC Microgrid." Journal of Engineering Sciences 7, no. 2 (2020): E7—E13. http://dx.doi.org/10.21272/jes.2020.7(2).e2.
Full textAbstract:
Renewable energy sources (RESs) are becoming increasingly important day by day to tranquilize the world’s energy crisis and consume fossil fuels in the lower rung. A microgrid system that assimilates clean and green energy-based sources such as solar, wind, and biogas is acquiring much prominence over the conventional grid-based power systems in this day and age. For the up and running of the inexhaustible energy sources in the AC power network, numerous conversions of the power sources occur. In the process of conversion, some amount of power is lost, which minimizes conversion efficiency. However, with the increasing use of DC loads and Distributed Energy Resources (DERs), DC Microgrid could be more beneficial than the conventional AC power system by avoiding several types of drawbacks. This paper demonstrates an efficient system of digitally controlled boost converter for the parallel operation in DC microgrid. Here, the converter of 2.5kW 400V is designed and implemented to validate its functioning in a Microgrid. The whole system has been simulated in MATLAB with an input voltage range of 220–380 V. It has been found that the designed converter can maintain the desired output voltage in the DC Busbar at and around 400 V. Finally, some simulation results have been presented to analyze the converter’s operational characteristics and effectiveness in the practical domain.
4
Vijayalakshmi, K., and Chinnapettai Ramalingam Balamurugan. "Z–Source Multilevel Inverter Based on Embedded Controller." Indonesian Journal of Electrical Engineering and Computer Science 6, no. 1 (April 1, 2017): 1. http://dx.doi.org/10.11591/ijeecs.v6.i1.pp1-8.
Full textAbstract:
<p>In this paper Embedded based Z-source multilevel inverter (ZSMLI) is proposed. This work implements a five level cascaded H-bridge Z-source inverter by using embedded control. Switching devices are triggered using embedded controller. In this controller coding is described by using switching table. The presence of Z-source network couples inverter main circuit to the power source that providing special features that can overcome the limitations of VSI (voltage source inverter) and CSI (current source inverter). The Z-source concept can applicable in all dc-ac, dc-dc, ac-dc and ac-ac power conversions. Simulation model of Z-source multilevel inverter based on embedded controller has been built in MATLAB/SIMULINK. The Performance parameters of Z-source MLI such as RMS (root mean square) output voltage, THD (total harmonic distortion) and DC component have been analysed for various inductance (L) and capacitance (C) value.</p>
5
Roomi, Muhammad M. "An Overview of Carrier-based Modulation Methods for Z-Source Inverter." Power Electronics and Drives 4, no. 1 (June 1, 2019): 15–31. http://dx.doi.org/10.2478/pead-2019-0007.
Full textAbstract:
AbstractSingle-stage energy converters, in particular, the Z-Source Inverter (ZSI) or impedance source inverter, has gained significant attention in the recent years. ZSI ensures flexible energy conversions (dc–dc, dc–ac, ac–ac and ac–dc) because of its unique ability to boost the output voltage in typical renewable energy systems. The impedance network integrated between the energy source and the load contributes to the unique functionality of the ZSI. As substantial research has been conducted on the ZSI, this article provides a review on the operation of ZSI. The article initially examines the various topologies commonly adopted for the application of the ZSI. Subsequently, details of the various modulation methods that are commonly used to obtain the voltage boosting using ZSI are documented. Additionally, the phenomenon of neutral point formation, which is an important impediment to the adoption of multilevel ZSIs and the limitation of the modulation methods, is explained.
6
Chaturvedi, Shivam, Mengqi Wang, Yaoyu Fan, Deepak Fulwani, Guilherme Vieira Hollweg, Shahid Aziz Khan, and Wencong Su. "Control Methodologies to Mitigate and Regulate Second-Order Ripples in DC–AC Conversions and Microgrids: A Brief Review." Energies 16, no. 2 (January 10, 2023): 817. http://dx.doi.org/10.3390/en16020817.
Full textAbstract:
Second-order ripples occur in the voltage and current during any DC–AC power conversion. These conversions occur in the voltage source inverters (VSIs), current source inverters (CSIs), and various single-stage inverters (SSIs) topologies. The second-order ripples lead to oscillating source node currents and DC bus voltages when there is an interconnection between the AC and DC microgrids or when an AC load is connected to the DC bus of the microgrid. Second-order ripples have various detrimental effects on the sources and the battery storage. In the storage battery, they lead to the depletion of electrodes. They also lead to stress in the converter or inverter components. This may lead to the failure of a component and hence affect the reliability of the system. Furthermore, the second-order ripple currents (SRCs) lead to ripple torque in wind turbines and lead to mechanical stress. SRCs cause a rise in the temperature of photovoltaic panels. An increase in the temperature of PV panels leads to a reduction in the power generated. Furthermore, the second-order voltage and current oscillations lead to a varying maximum power point in PV panels. Hence, the maximum power may not be extracted from it. To mitigate SRCs, oversizing of the components is needed. To improve the lifespan of the sources, storage, and converter components, the SRCs must be mitigated or kept within the desired limits. In the literature, different methodologies have been proposed to mitigate and regulate these second-order ripple components. This manuscript presents a comprehensive review of different effects of second-order ripples on different sources and the methodologies adopted to mitigate the ripples. Different active power decoupling methodologies, virtual impedance-based methodologies, pulse width modulation-based signal injection methodologies, and control methods adopted in distributed power generation methods for DC microgrids have been presented. The application of ripple control methods spans from single converters such as SSIs and VSIs to a network of interconnected converters. Furthermore, different challenges in the field of virtual impedance control and ripple mitigation in distributed power generation environments are discussed. This paper brings a review regarding control methodologies to mitigate and regulate second-order ripples in DC–AC conversions and microgrids.
7
Piao, Longjian, Laurens de Vries, Mathijs de Weerdt, and Neil Yorke-Smith. "Electricity Markets for DC Distribution Systems: Design Options." Energies 12, no. 14 (July 10, 2019): 2640. http://dx.doi.org/10.3390/en12142640.
Full textAbstract:
DC distribution systems (DCDSs) are a promising alternative to AC systems because they remove AC-DC conversions between renewable sources and loads. Their unique features compared to AC include low system inertia, strict power limits and power–voltage coupling. In a liberalised electricity market, merely applying an AC market design to a DCDS cannot guarantee the latter’s supply security and voltage stability; new markets must be designed to meet DC challenges. This article identifies the key design options of DCDS electricity markets. To identify these options, we develop a comprehensive design framework for local electricity markets; to our knowledge, we provide the first such analysis. Whereas previous studies focus on separate aspects of DCDS markets, we widen the scope to include the role of market architecture and investigate the arrangements of sub-markets. As an illustration, we demonstrate three promising DCDS market designs that can be defined in our framework, and provide a first assessment of their performance.
8
Razzaq, Syed Abdul, and Vairavasamy Jayasankar. "Autonomous power sharing for AC/DC HMGS using decentralized modified droop method for interlinking converter." International Journal of Power Electronics and Drive Systems (IJPEDS) 13, no. 4 (December 1, 2022): 2139. http://dx.doi.org/10.11591/ijpeds.v13.i4.pp2139-2147.
Full textAbstract:
<p>The present trend of integrating renewable energy sources (RES) in AC/DC hybrid micro grid systems (HMGS) has certainly reduced the greenhouse gases and provides the variety of power sources for micro grid (MG). Interlinking converter (ILC) is the main converter for interconnecting AC/DC sub-grids with a variety of features like autonomous bidirectional power sharing, reducing the power conversions in the grid and additionally a featuring aspect for energy management system (EMS). Interlinking converters are desired to maintain stable frequency, constant voltages at buses, reduce the power losses, reduce switching losses and control on circulating currents, most of the control methods could not achieve all. In this paper, the decentralized modified droop control method is presented which is significant in meeting the autonomous bidirectional AC/DC power load demand and in achieving the desired features. A three coordinated model is proposed where AC frequency, ILC power and DC voltage are the corresponding axis. The power sharing through the ILC is dependent on the AC frequency droop and DC voltage droop which occurs due to overloading. This control scheme is compatible for interconnection with multi-port grids. This control schemes provide more reliable, stable and accurate results compare to conventional droop methods.</p>
9
Johar, Harminder Singh, Abhijit Bhattacharyya, and Srinivas Rao S. "Fault Tolerant Power Supply for Aircraft Store Interface." Defence Science Journal 72, no. 5 (November 1, 2022): 679–86. http://dx.doi.org/10.14429/dsj.72.17737.
Full textAbstract:
This paper brings out the design of a fault-tolerant power supply unit for the aircraft-store interface. This switched mode power supply provides multiple 30 V regulated and isolated DC outputs required for pre-launch preparations and auto-launch operations of avionic sub-systems in a store. 3Ø-115V-400Hz-AC supply as well as 27V-DC supply are available from a fighter aircraft for powering up of any store. Power (wattage) output from 27V/10A DC is inadequate to power up various onboard avionic sub-systems in guided stores involving seekers and other avionics. Hence, it is planned to convert available high power 3Ø-115V-400Hz-AC supply for applications requiring higher wattages (of the order of 500 watts or more). This power supply provides multiple output options of 30V regulated and isolated DC supply with multiple input supplies from Aircraft, viz. 3Ø-115V-400Hz-AC, 1Ø-115V-400Hz-AC and 27V DC. One of the outputs provided is with hold-up capacitors, to cater for any input power interruptions as per requirements of MIL-STD-704F and GOST-19705-89 standards. This power supply is a ready-to-connect device and essentially consists of housing, components of DC to DC conversions, EMI/EMC filters, solid state power controllers, control switches, and control circuitry for monitoring signals.
10
Othee, Avpreet, James Cale, Arthur Santos, Stephen Frank, Daniel Zimmerle, Omkar Ghatpande, Gerald Duggan, and Daniel Gerber. "A Modeling Toolkit for Comparing AC and DC Electrical Distribution Efficiency in Buildings." Energies 16, no. 7 (March 25, 2023): 3001. http://dx.doi.org/10.3390/en16073001.
Full textAbstract:
Recently, there has been considerable research interest in the potential for DC distribution systems in buildings instead of the traditional AC distribution systems. Due to the need for performing power conversions between DC and AC electricity, DC distribution may provide electrical efficiency advantages in some systems. To support comparative evaluations of AC-only, DC-only, and hybrid AC/DC distribution systems in buildings, a new modeling toolkit called the Building Electrical Efficiency Analysis Model (BEEAM) was developed and is described in this paper. To account for harmonics in currents or voltages arising from nonlinear devices, the toolkit implements harmonic power flow, along with nonlinear device behavioral descriptions derived from empirical measurements. This paper describes the framework, network equations, device representations, and an implementation of the toolkit in an open source software package, including a component library and graphical interface for creating circuits. Simulations of electrical behavior and device and system efficiencies using the toolkit are compared with experimental measurements of a small office environment in a variety of operating and load configurations. A detailed analysis of uncertainty estimation is also provided. Key findings were that a comparison of predicted versus measured efficiencies and power losses in the validation testbed using the initial toolkit implementation predicted device- and system-level efficiencies with reasonably good accuracy under both balanced and unbalanced AC scenarios. An uncertainty analysis also revealed that the maximum estimated error for system efficiency across all scenarios was 3%, and measured and modeled system efficiency agreed within the experimental uncertainty in approximately half of the scenarios. Based on the correspondence between simulation and measurement, the toolkit is proposed by the authors as a potentially useful tool for comparing efficiency in AC, DC, and hybrid AC/DC distribution systems in buildings.
Dissertations / Theses on the topic "DC-AC CONVERSIONS"
1
Wang, Kunrong. "High-Frequency Quasi-Single-Stage (QSS) Isolated AC-DC and DC-AC Power Conversion." Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/29394.
Full textAbstract:
The generic concept of quasi-single-stage (QSS) power conversion topology for ac-dc rectification and dc-ac inversion is proposed. The topology is reached by direct cascading and synchronized switching of two variety of buck or two variety of boost switching networks. The family of QSS power converters feature single-stage power processing without a dc-link low-pass filter, a unidirectional pulsating dc-link voltage, soft-switching capability with minimal extra commutation circuitry, simple PWM control, and high efficiency and reliability.
A new soft-switched single-phase QSS bi-directional inverter/rectifier (charger) topology is derived based on the QSS power conversion concept. A simple active voltage clamp branch is used to clamp the otherwise high transient voltage on the current-fed ac side, and at the same time, to achieve zero-voltage-switching (ZVS) for the switches in the output side bridge. Seamless four-quadrant operation in the inverter mode, and rectifier operation with unity power factor in the charger (rectifier) mode are realized with the proposed uni-polar center-aligned PWM scheme. Single-stage power conversion, standard half-bridge connection of devices, soft-switching for all the power devices, low conduction loss, simple center-aligned PWM control, and high reliability and efficiency are among its salient features. Experimental results on a 3 kVA bi-directional inverter/rectifier prototype validate the reliable operation of the circuit. Other single-phase and three-phase QSS bi-directional inverters/rectifiers can be easily derived as topological extensions of the basic QSS bi-directional inverter/rectifier.
A new QSS isolated three-phase zero-voltage/zero-current-switching (ZVZCS) buck PWM rectifier for high-power off-line applications is also proposed. It consists of a three-phase buck bridge switching under zero current and a phase-shift-controlled full-bridge with ZVZCS, while no intermediate dc-link is involved. Input power and displacement factor control, input current shaping, tight output voltage regulation, high-frequency transformer isolation, and soft-switching for all the power devices are realized in a unified single stage. Because of ZVZCS and single-stage power conversion, it can operate at high switching frequency while maintaining reliable operation and achieving higher efficiency than standard two-stage approaches. A family of isolated ZVZCS buck rectifiers are obtained by incorporating various ZVZCS schemes for full-bridge dc-dc converters into the basic QSS isolated buck rectifier topology. Experimental and simulation results substantiate the reliable operation and high efficiency of selected topologies.
The concept of charge control (or instantaneous average current control) of three-phase buck PWM rectifiers is introduced. It controls precisely the average input phase currents to track the input phase voltages by sensing and integrating only the dc rail current, realizes six-step PWM, and features simple implementation, fast dynamic response, excellent noise immunity, and is easy to realize with analog circuitry or to integrate. One particular merit of the scheme is its capability to correct any duty-cycle distortion incurred on only one of the two active duty-cycles which often happens in the soft-switched buck rectifiers, another merit is the smooth transition of the input currents between the 60o sectors. Simulation and preliminary experimental results show that smooth operations and high quality sinusoidal input currents in the full line cycle are achieved with the control scheme.Ph. D.
2
McClure, Morgan Taylor. "A Modular Architecture for DC-AC Conversion." Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1340812711.
Full text
3
Steckler, Pierre-Baptiste. "Contribution à la conversion AC/DC en Haute Tension." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI075.
Full textAbstract:
Le courant alternatif (AC) se prêtant bien à la majorité des problématiques de production, de transport et de distribution de l'électricité, on comprend qu'il soit massivement utilisé. Cependant, depuis plus d'un siècle, les bénéfices du courant continu haute tension (HVDC, pour High Voltage Direct Current) pour les longues distances sont bien connus. Aux interfaces, des convertisseurs AC/DC sont requis, leur composition évoluant au fil des avancées technologiques. Après avoir présenté les spécificités du HVDC et les contraintes qu'il introduit sur les convertisseurs AC/DC, ce manuscrit se focalise sur trois topologies : Modular Multilevel Converter (MMC), Alternate Arm Converter (AAC) et Series Bridge Converter (SBC). Elles sont présentées, dimensionnées et analysées en détail, puis comparées de façon quantitative en utilisant des indicateurs de performance originaux. Il en ressort que le MMC et le SBC sont particulièrement intéressants. La méthode de commande conventionnelle du MMC est ensuite présentée et ses propriétés structurelles sont mises en évidence. Une première loi de commande originale est présentée, avec des performances similaires mais une complexité inférieure à l'état de l'art. La seconde est non linéaire, basée sur la théorie de la platitude différentielle, et permet un suivi de puissance très rapide tout en assurant la stabilité exponentielle globale du système. Ces lois de commande sont évaluées en simulation, avec un modèle moyen et un modèle détaillé intégrant 180 sous-modules par bras. La dernière partie concerne le SBC. Après l'avoir modélisé, des résultats concernant une analyse structurelle de la topologie sont présentés ainsi qu'une loi de commande originale. Le rôle fondamental du transformateur pour les convertisseurs à structure série comme le SBC est souligné. Enfin, les performances de la loi de commande proposée sont testées en simulationAs Alternating Current (AC) is well suited for most of the production, transmission, and distribution applications, its massive use is easy to understand. However, for over a century, the benefits of High Voltage Direct Current (HVDC) for long-distance energy transmission are well known. To connect both, AC/DC converters are mandatory, whose nature evolves with technological progress. After the problematic induced by HVDC on AC/DC converters is presented, this manuscript is focused on three topologies: Modular Multilevel Converter (MMC), Alternate Arm Converter (AAC) and Series Bridge Converter (SBC). They are presented, sized, analyzed thoroughly, and compared in quantitative terms, using original key performance indicators. It appears that MMC and SBC are particularly promising. The conventional control method of the MMC is then presented, and its structural properties are highlighted. A first original control law is presented, with similar performances but less complexity than the state-of-the-art. A second control law, non-linear and based on differential flatness theory, is introduced. It allows a very fast power tracking response while ensuring the global exponential stability of the system. These control laws are tested in simulation, using an average model and a detailed model with 180 sub-modules per arm. The last part is dedicated to the SBC. After a modeling step, some results regarding its structural analysis are presented, and an original control law is introduced. The essential role of the transformer for series converters like the SBC is highlighted. Finally, the performance of the proposed control law is assessed in simulation
4
Liang, Chenchen. "Contribution à l'étude d'une chaîne de conversion d'énergie AC-DC / DC-DC tolérantes aux défauts." Thesis, Nantes, 2017. http://www.theses.fr/2017NANT4080/document.
Full textAbstract:
Pour répondre au contexte d’exploitation des énergies renouvelables marines où l’accès aux systèmes de production d’énergie électrique est délicat, cette thèse porte sur l’étude d’une chaîne de conversion d’énergie tolérante aux défauts. Trois volets sont investigués : l’analyse comportementale de la topologie, le contrôle de la puissance produite ainsi que la détection et la localisation des défauts. La chaîne est constituée d’une MSAP pentaphasée, d’un redresseur à diodes à 5 bras et de 3 convertisseurs DC-DC de type Boost entrelacés. Pour la stratégie de contrôle de la puissance de sortie, un double asservissement est appliqué au bloc DC-DC. Des modèles dynamiques petits signaux sont établis. La boucle interne est dédiée à l’asservissement du courant d'entrée de l’étage Boost et la boucle externe au contrôle de la puissance. Trois types de régulateurs en courant sont étudiés et comparés. Des approches de synchronisation des commandes des 3 Boosts sont proposées. Il ressort que le régulateur non linéaire, dit MRC, satisfait complètement aux performances désirées. Le contrôle de puissance, intégré ensuite dans la chaîne complète de production d’énergie et testé pour différents modes de fonctionnement sains et dégradés, est de très bon niveau. Des méthodes de détection et de localisation des défauts au niveau de l’entrée et de la sortie du redresseur ont été développées. En se basant sur la mesure des courants de phase ou sur la mesure de la tension en sortie du redresseur, les défauts côté AC sont détectés et localisés. La détection côté continu est de faible complexité. Cette méthode est ensuite étendue aux défauts de l’étage DC-DC en utilisant son courant d’entréeTo answer the context of marine renewable energy exploitation where the access of energy production system is difficult, this thesis deals with the study of a fault tolerant energy conversion chain. Three aspects are investigated: behavior analysis of the topology; output power control; detection and location of faults. The chain involves a five-phase PMSG, a five-leg diode rectifier and a three-interleaved DC-DC Boost converter. Concerning the output power control strategy, a double-loop control is applied on the DC-DC block. Small-signal dynamic models are established. The inner loop is used for controlling the input current of the Boost stage. The outer loop is for the output power. Three types of current controllers are studied and compared. Methods of synchronization for the three-interleaved Boost converter control are proposed. It results that the nonlinear controller, called in French version, the MRC, totally satisfies the desired performances. The control of power, which is then used for the full conversion chain, is tested under different operating modes (health and fault) and is of high performances. Several methods for detecting and locating rectifier’s AC and DC side faults have been developed. Based on the measurements of phase currents or the measurement of the output voltage of the rectifier, AC side faults can be detected and located. DC measurement based fault detection is of low complexity. This method is then extended to the faults of DC-DC block by using its input current
5
Chen, Weilun Warren. "Bidirectional Three-Phase AC-DC Power Conversion Using DC-DC Converters and a Three-Phase Unfolder." DigitalCommons@USU, 2017. https://digitalcommons.usu.edu/etd/6905.
Full textAbstract:
Strategic use of energy storage systems alleviates imbalance between energy generation and consumption. Battery storage of various chemistries is favorable for its relatively high energy density and high charge and discharge rates. Battery voltage is in dc, while the distribution of electricity is still predominantly in ac. To effectively harness the battery energy, a dc-ac inverter is required.
A conventional inverter contains two high-frequency switching stages. The battery-interfacing stage provides galvanic isolation and switches at high frequency to minimize the isolation transformer size. The grid-interfacing stage also operates at high frequency to obtain sinusoidal grid currents and the desired power. Negative consequences of high-frequency switching include increased switching loss and the generation of large voltage harmonics that require filtering.
This dissertation proposes an alternative two-stage inverter topology aimed at reducing converter size and weight. This is achieved by reducing the number of high-frequency switching stages and associated filter requirements. The grid-interfacing stage is operated at the line frequency, while only the battery-interfacing stage operates at high frequency to shape the line currents and control power flow. The line-frequency operation generates negligible switching loss and minimal current harmonics in the grid-interfacing stage. As a result, the required filter is reduced in size. Hardware designs are performed and compared between the conventional and proposed converters to quantify expected size reduction. Control methods are developed and verified in simulation and experiment to obtain high-quality line currents at all power factors.
6
Al-Mothafar, M. R. D. "High frequency inverter-cycloconverter system for DC to AC conversion." Thesis, University of Bath, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378135.
Full text
7
Belkacem, Faraheddine. "Contribution à la commande des convertisseurs DC-AC alimentés par un panneau photovoltïque." Amiens, 2006. http://www.theses.fr/2006AMIE0618.
Full textAbstract:
Le travail mené concerne le développement d’une alimentation de secours robuste et à faible coût pouvant délivrer une tension sinusoïdale de 230V-50Hz et une puissance active allant jusqu’à 50W à partir d’un unique panneau photovoltaïque qui peut délivrer une puissance continue jusqu’à 50W. Ce système de puissance est composé de deux étages de conversion : un convertisseur DC-DC à gain élevé (≈ 20) constitué par la mise en cascade de deux cellules élévatrices de tension de type Boost et d’un onduleur monophasé en pont complet associé à un filtre LC. La première partie du travail a consisté à dimensionner l’alimentation avec le souci de concevoir une structure robuste et surtout ayant un bon rendement. Nous avons ensuite développé et comparé deux stratégies de contrôle pour asservir la tension de sortie du convertisseur DC-DC avec la contrainte de ne mesurer que le courant d’entrée et la tension de sortie parmi les quatre variables d’état. La première stratégie est un contrôleur linéaire basé sur un correcteur PI et la seconde est un contrôleur à structure variable en mode glissant. Pour les deux techniques de contrôle les méthodes de réglage ont été développées et une évaluation des performances statiques et dynamiques ainsi que la robustesse vis-à-vis des variations de la charge a été réalisée. Parallèlement à ce travail nous avons développé un module de poursuite du point de puissance maximale (MPPT) validé en simulation numérique. Il permet d’adapter la source photovoltaïque à la charge en déterminant le point de fonctionnement du panneau dans le plan (I,V) pour toujours extraire la puissance maximale du panneau.
8
Grant, David. "High power density AC to DC conversion with reduced input current harmonics." Thesis, University of Newcastle upon Tyne, 2015. http://hdl.handle.net/10443/3906.
Full textAbstract:
This thesis investigates the bene ts and challenges arising from the use of minimal capacitance in AC to DC converters. The purpose of the research is to ultimately improve the power density and power factor of electrical systems connected to the grid. This is carried out in the con- text of a low cost brushless DC drive system operating from an o ine power supply. The work begins with a review of existing applications where it is prac- tical to use a limited amount of DC link capacitance. The vast majority of these have a load which is insensitive to supply power variations at twice the line frequency. Low performance motor drives are found to be the most prevalent, with the inertia of the rotor mitigating the e ect of torque ripple. Further research is carried out on active power factor cor- rection techniques suitable for this application, leading to the conclusion that no appropriate systems exist. A power supply is developed to enable a 24V, 200W brushless motor drive to operate from the mains. The system runs successfully using only 1μF of DC link capacitance, which causes the motor supply volt- age to have 100% ripple. It is noted that whilst this drastically reduces the low frequency input current harmonics, those occurring at the load switching frequency are greatly increased. To combat this, a novel active power factor correction system is proposed using a notch lter to detect the input current error. The common problem of voltage feedback ripple is avoided by eliminating the voltage control loop altogether. The main limitations are identi ed as a high sensitivity to load step changes and variations in line frequency. Despite this, a high power factor is maintained in all operating conditions, as well as compliance with the relevant harmonic standards.
9
Lopez, Santos Oswaldo. "Contribution to the DC-AC conversion in photovoltaic systems : Module oriented converters." Thesis, Toulouse, INSA, 2015. http://www.theses.fr/2015ISAT0001/document.
Full textAbstract:
Ces dernières années, un intérêt croissant pour les systèmes électroniques de puissance a été motivé par l'émergence de sources d'énergie distribuées et renouvelables raccordées aux réseaux électriques. Dans ce contexte, la nécessité de topologies de faibles puissances alimentées par quelques modules photovoltaïques, en évitant l'utilisation de transformateurs, a ouvert l'étude de convertisseurs spéciaux et l’étude des stratégies de commande associées afin d’assurer la stabilité, la fiabilité et un rendement élevé du dispositif. Une possible solution est d’utiliser un dispositif générique connu dans la littérature scientifique et commerciale comme « micro-onduleur » ou «convertisseur intégré au module » qui avec le module photovoltaïque définit un produit « plug and play » appelé "module AC".Ce travail est consacré à l'étude d'un micro-onduleur monophasé avec deux étapes sans transformateur raccordée au réseau. La topologie proposée est composé d’un convertisseur DC-DC non isolé élévateur avec un gain quadratique et un onduleur réducteur lié au réseau connectés en cascade. Le convertisseur DC-DC extrait en permanence la puissance maximale du module photovoltaïque malgré les changements dans les conditions environnementales. L'étape DC-AC injecte la puissance extraite par l'étape DC-DC dans le réseau et assure un niveau élevé de qualité de l’énergie. Les efforts de recherche de ce travail sont concentrés sur la mise au point de commandes utilisant comment base, la théorie de contrôle par mode de glissement, qui conduit à une mise en œuvre simple avec une description théorique complète validée á partir de simulations et expérimentations.Après avoir décrit l'état de l’art dans le premier chapitre, le manuscrit est divisé en quatre chapitres, qui sont dédiés respectivement à l’algorithme de recherche du point de puissance maximale (MPPT), á l’étape de conversion DC-DC, á l'étape de conversion DC-AC et finalement au micro-onduleur complet. Un nouvel algorithme de recherche extrémal du point de puissance maximale est développé (SM-ESC). Pour la étape DC-DC, le convertisseur élévateur quadratique avec seulement un interrupteur contrôlé est étudié utilisant le concept de résistance sans perte par mode de glissement (de l’acronyme anglais : Sliding-Mode Loss-Free-Resistor – SM-LFR) afin d’obtenir un gain de tension élevé avec un fonctionnement sûr et compatible avec l’algorithme MPPT. Pour la étape DC-AC, le convertisseur de pont complet est contrôlé comme un onduleur de source de puissance (de l’acronyme anglais : Power Source Inverter - PSI) en utilisant une commande par mode de glissement qui poursuit une référence sinusoïdale de courant de sortie. Cette commande est complétée par une boucle de régulation de la tension du bus DC qui assure une haute qualité d’énergie injectée dans le réseau. Enfin, les trois étapes constitutives sont fusionnées pour obtenir un micro-onduleur complètement contrôlé par la technique de mode de glissement, ce qui constitue le principal résultat et contribution de cette thèseThese last years, a growing interest in power electronic systems has been motivated by the emergence of distributed renewable energy resources and their interconnection with the grid. In this context, the need of low power topologies fed by a few photovoltaic modules avoiding the use of transformers opens the study of special converters and the associated control strategies ensuring stability, reliability and high efficiency. A resulted generic device known in the commercial and scientific literature as “microinverter” or “module integrated converter” performs a plug and play product together with the PV module called an “AC module”.This work is devoted to the study of a transformer-less single-phase double-stage grid-connected microinverter. The proposed topology has a non-isolated high-gain boost type DC-DC converter and a non-isolated buck type DC-AC converter connected in cascade through a DC bus. The DC-DC converter permanently extracts the maximum power of the PV module ensuring at the same time a good performance coping with power changes introduced by the change in the environmental conditions. The DC-AC stage injects the power extracted by the DC-DC stage into the grid ensuring a high level of power quality. The research efforts focus on the involved control functions based on the sliding mode control theory, which leads to a simple implementation with a comprehensive theoretical description validated through simulation and experimental results.After giving the state-of-the-art in the first chapter, the manuscript is divided into four chapters, which are dedicated to the Maximum Power Point Tracking (MPPT), the DC-DC stage and its control, the DC-AC stage and its control and the complete microinverter. A new Extremum Seeking Control (ESC) MPPT algorithm is proposed. The single-switch quadratic boost converter is studied operating as a Loss-Free-Resistor (LFR) obtaining a high DC output voltage level with a safe operation. The full-bridge converter is controlled as a Power Source Inverter (PSI) using a simple sliding-mode based tracking law, regulating the voltage of the DC bus and then ensuring a high power quality level in the grid connection. Finally, the three building blocks are merged to obtain a sliding mode controlled microinverter constituting the main result and contribution of the work
10
Song, Yu Jin. "Analysis and design of high frequency link power conversion systems for fuel cell power conditioning." Diss., Texas A&M University, 2004. http://hdl.handle.net/1969.1/2678.
Full textAbstract:
In this dissertation, new high frequency link power conversion systems for the fuel cell power conditioning are proposed to improve the performance and optimize the cost, size, and weight of the power conversion systems. The first study proposes a new soft switching technique for the phase-shift controlled bi-directional dc-dc converter. The described dc-dc converter employs a low profile high frequency transformer and two active full-bridge converters for bidirectional power flow capability. The proposed new soft switching technique guarantees soft switching over wide range from no load to full load without any additional circuit components. The load range for proposed soft switching technique is analyzed by mathematical approach with equivalent circuits and verified by experiments. The second study describes a boost converter cascaded high frequency link direct dc-ac converter suitable for fuel cell power sources. A new multi-loop control for a boost converter to reduce the low frequency input current harmonics drawn from the fuel cell is proposed, and a new PWM technique for the cycloconverter at the secondary to reject the low order harmonics in the output voltages is presented. The performance of the proposed scheme is verified by the various simulations and experiments, and their trade-offs are described in detail using mathematical evaluation approach. The third study proposes a current-fed high frequency link direct dc-ac converter suitable for residential fuel cell power systems. The high frequency full-bridge inverter at the primary generates sinusoidally PWM modulated current pulses with zero current switching (ZCS), and the cycloconverter at the secondary which consists of only two bidirectional switches and output filter capacitors produces sinusoidally modulated 60Hz split single phase output voltage waveforms with near zero current switching. The active harmonic filter connected to the input terminal compensates the low order input current harmonics drawn from the fuel cell without long-term energy storage devices such as batteries and super capacitors.
Books on the topic "DC-AC CONVERSIONS"
1
Séguier, Guy. Power Electronic Converters: DC-AC Conversion. Berlin, Heidelberg: Springer Berlin Heidelberg, 1993.
Find full text
2
Séguier, Guy. Power electronic converters: DC-AC conversion. Berlin: Springer-Verlag, 1993.
Find full text
3
Séguier, Guy. Power electronic converters: AC-DC conversion. New York: McGraw-Hill, 1986.
Find full text
4
Seguier, Guy. Power electronic converters: AC-DC conversion. London: North Oxford Academic, 1986.
Find full text
5
Karamat, Asghar. High frequency inverter-transformer-cycloconverter system for DC to AC (3-phase) power conversion. Uxbridge: Brunel University, 1991.
Find full text
6
Prohorov, Viktor. Semiconductor converters of electrical energy. ru: INFRA-M Academic Publishing LLC., 2020. http://dx.doi.org/10.12737/1019082.
Full textAbstract:
The textbook considers the need, principles and methods of mutual conversion of parameters of electric energy at DC and AC for stationary and Autonomous objects. Features of operation of power electronics elements in specific conditions of their continuous high-frequency switching are described. Low-current control systems that provide the necessary logic for the operation of Executive power devices of converters are considered. A large number of specific practical electrical diagrams of electric energy converters are given.
It is intended for students studying in the direction of 13.03.02 "electric power and electrical engineering". It can be useful for graduate students and specialists involved in the development and operation of electric power converters.
7
Power Electronics and Energy Conversion Systems, AC / DC and DC / AC Power Conversion. Wiley & Sons, Incorporated, John, 2021.
Find full text
8
Wolf, E. L. Energy Storage, Distribution, Use and Climate Impact. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198769804.003.0011.
Full textAbstract:
The large-scale energy grid often comprises both AC and DC transmission lines. DC transmission at ultrahigh voltages is more efficient, but consumers need AC at lower voltage so that AC/DC conversion stations are key elements. In modern conversion stations large silicon thyristors are key devices. Energy storage in pumped-hydro installations can be supplemented by compressed air storage. Thermal plants can store energy in molten salts to provide continuous power for consumers. Battery technology is expensive at grid scale but is expanding. The possibility of carbon capture at power plants is discussed. Energy in this chapter is assumed to be electrical energy, with a large portion devoted to the electric grid.
Book chapters on the topic "DC-AC CONVERSIONS"
1
Arrillaga, Jos, Bruce C. Smith, Neville R. Watson, and Alan R. Wood. "AC-DC Conversion-Frequency Domain." In Power System Harmonic Analysis, 133–71. West Sussex, England: John Wiley & Sons, Ltd, 2013. http://dx.doi.org/10.1002/9781118878316.ch5.
Full text
2
Arrillaga, Jos, Bruce C. Smith, Neville R. Watson, and Alan R. Wood. "AC-DC Conversion-Harmonic Domain." In Power System Harmonic Analysis, 223–40. West Sussex, England: John Wiley & Sons, Ltd, 2013. http://dx.doi.org/10.1002/9781118878316.ch8.
Full text
3
Ikegawa, S., T. Honda, H. Ikeda, A. Maeda, H. Takagi, S. Uchida, K. Uchinokura, and S. Tanaka. "AC-DC Conversion Effect in Ceramic Superconductor." In Advances in Superconductivity, 743–48. Tokyo: Springer Japan, 1989. http://dx.doi.org/10.1007/978-4-431-68084-0_126.
Full text
4
Saha, Jaydeep. "Three-Phase Matrix-Based Isolated AC-DC Conversion." In Springer Theses, 187–215. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-4902-9_6.
Full text
5
Zhang, Chenghui, Le Chang, and Cheng Fu. "Variable Gain Control of Three-Phase AC/DC Power Converters." In Variable Gain Control and Its Applications in Energy Conversion, 125–36. Boca Raton: CRC Press, 2023. http://dx.doi.org/10.1201/9781003392927-11.
Full text
6
Anusha, H., and S. B. Naveen Kumar. "Bidirectional Power Conversion by DC–AC Converter with Active Clamp Circuit." In Lecture Notes in Electrical Engineering, 1283–94. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-5802-9_109.
Full text
7
Zhang, Xin, Fanfan Lin, Hao Ma, Bin Zhao, and Jingjing Huang. "Multi-time Scale Frequency Regulation of a General Resonant DC Transformer in Hybrid AC/DC Microgrid." In Holistic Design of Resonant DC Transformer on Constant Voltage Conversion, Cascaded Stability and High Efficiency, 211–35. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-9115-8_8.
Full text
8
Ruan, Xinbo, Wu Chen, Tianzhi Fang, Kai Zhuang, Tao Zhang, and Hong Yan. "A General Control Strategy for DC–AC Series–Parallel Power Conversion Systems." In CPSS Power Electronics Series, 107–19. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-2760-5_5.
Full text
9
Zhang, Xin, Fanfan Lin, Hao Ma, Bin Zhao, and Jingjing Huang. "The Proposed Robust Circuit Parameters Design for the CLLC-Type DC Transformer in the Hybrid AC/DC Microgrid." In Holistic Design of Resonant DC Transformer on Constant Voltage Conversion, Cascaded Stability and High Efficiency, 11–43. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-9115-8_2.
Full text
10
Rafi, Shaik, Simhadri Lakshmi Sirisha, and Ravipati Srikanth. "A Hybrid Power Conversion System Using Three-Phase Single-Stage DC–AC Converter." In Lecture Notes in Electrical Engineering, 243–54. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-2256-7_24.
Full textConference papers on the topic "DC-AC CONVERSIONS"
1
Sreeram, K. "Universal matrix converter for AC and DC power conversions." In 2017 IEEE International Conference on Circuits and Systems (ICCS). IEEE, 2017. http://dx.doi.org/10.1109/iccs1.2017.8326029.
Full text
2
Reddy, P. P., and D. Lee. "Simplifying SCR to AC Rig Conversions to Deploy Digital and Automated Drilling Technologies." In SPE/IADC Middle East Drilling Technology Conference and Exhibition. SPE, 2023. http://dx.doi.org/10.2118/214555-ms.
Full textAbstract:
Abstract Advancements in drilling control system technologies enable gains in efficiency and repeatability. Recent developments also frequently include automation. To achieve these improvements, the industry is developing and introducing new control tools with rapid speed. However, not all drilling contractors are able to leverage these new advancements in machine controls. Capitalizing on the new technologies requires that drilling rigs are running current generation Alternating Current (AC) drawworks and are fitted with controls system architecture suitable for this generation of hardware. Simply put, the industry is not developing Digital and Automated Drilling Control technology for dated, legacy drawworks run by direct current (DC) silicon-controlled rectifier (SCR) systems. This is a problem for many rigs in the fleet. Because these rigs have antiquated hardware, they cannot be outfitted with the latest control systems without being upgraded with AC hardware platforms and equipment. This leaves many rigs lacking features and technologies that make them more capable and more competitive. Upgrades require an investment, and the cost and time associated with making hardware changes has been a barrier to entry for drilling contractors eager to capitalize on the new controls system technologies. Historically, converting an SCR rig to AC technology required that the rig be rebuilt entirely. There are obvious incentives for upgrading ageing rigs, but the traditional approach to carrying out an upgrade is too time- and cost-intensive. The industry needs an affordable way to upgrade outmoded assets that can be implemented without resulting in extensive non-productive time (NPT) or lost revenue. A new approach has been introduced to simplify the process. By swapping the existing direct current (DC) top drive and DC drawworks with AC models and adding a compact driller's cabin equipped with built-in drives to power and control the top drive and drawworks, an upgrade can be performed during a rig move. Using this upgrade method, an older rig can be outfitted to interface with new technologies to capture efficiency gains within a significantly shortened timeline. This solution is feasible, but to enable execution, all upgrades must be tailored specifically to the rig layout. Before any work can be undertaken, thorough pre-planning discussions must take place among the parties involved, including management, finance, engineering, operations, and project execution teams. A recent upgrade carried out during a rig move for a 2,000-horsepower class rig working in Saudi Arabia demonstrates how a field- retrofit solution makes it possible to quickly and cost-effectively convert any SCR drilling rig to AC without incurring extensive NPT.
3
Hashim, Hazem, and Asmarashid Ponniran. "Optimization of Wireless Power Transfer Configuration for High Efficiency Achievement." In Conference on Faculty Electric and Electronic 2020/1. Penerbit UTHM, 2020. http://dx.doi.org/10.30880/eeee.2020.01.01.010.
Full textAbstract:
This paper discusses the efficiency improvement of a wireless power transfer system based on parameters design optimization. The wireless power transfer system is designed to operate at higher frequencies in order to reduce the component sizing as well as power density improvement. Configuration of the wireless power transfer system, i.e., transmitter and receiver coil are designed based on proper resonance frequency. The principle of the parameters design optimization is based on the single transmitter – multiple receiver coil configuration which reduces the system complexity and magnetic resonant method implementation which amplify the energy transferred between the coils. Simulation using ANSYS Maxwell and ANSYS Simplorer software shows the system efficiency is at the peak at the resonance frequency of 13.5571 MHz with a total power of 18 W delivered at a distance of 5 mm. Furthermore, the efficiency of AC – DC converter and high frequency DC – AC converter considered for power conversions are 99.81% and 99.51% respectively. Therefore, the maximum power transfer efficiency of the considered wireless power transfer system configuration is determined through this study.
4
Su, Mei, Ziyi Zhao, Qi Zhu, and Hanbing Dan. "A converter based on energy injection control for AC-AC, AC-DC, DC-DC, DC-AC conversion." In 2018 13th IEEE Conference on Industrial Electronics and Applications (ICIEA). IEEE, 2018. http://dx.doi.org/10.1109/iciea.2018.8397927.
Full text
5
"Session 28 AC-DC conversion." In 2008 Twenty-Third Annual IEEE Applied Power Electronics Conference and Exposition. IEEE, 2008. http://dx.doi.org/10.1109/apec.2008.4522675.
Full text
6
Turki, Hedia, and Mohamed Elleuch. "Transformer modeling suitable for DC/AC and AC/DC conversion chains." In 2014 11th International Multi-Conference on Systems, Signals & Devices (SSD). IEEE, 2014. http://dx.doi.org/10.1109/ssd.2014.6808835.
Full text
7
Mitsumoto, Yuta, Norihiro Kose, and Tsuguhiko Nakagawa. "High Rate Interactive Energy System Through the Use of PV and EV." In ASME 2013 Power Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/power2013-98137.
Full textAbstract:
After the Great East Japan Earthquake disaster, it was necessary to build a new energy system that would enable us to be less dependent on nuclear power, as well as reduce carbon dioxide emissions. To accomplish this, it is necessary to consider a new method of energy supply and consumption combined with the promotion of energy conservation and the increased use of natural energy. One example, called “Smart Community”, has attracted attention. It optimizes a balance between energy supply and demand, and utilizing energy efficiently. The “Smart Community” is envisioned as different from the conventional one-way power system currently supplied by electric and fuel companies. In this study, the authors investigate a way to efficiently use photovoltaic (PV) power in an interactive energy system. In the system, PV power is used in homes and factories as an energy source, and in electric vehicles (EV) for transportation and energy storage. The system is a two-way system, and it is important for users to determine which supply and demand method they want. For example, if you choose to include PV power in your electrical power system, there will be the problem of increased DC-AC conversion energy loss. This is due to the re-conversion of AC-DC after DC-AC conversion. In addition, the cost will increase. In order to solve this problem, the authors propose an efficient installation location and space for PV, and an optimized battery capacity for EV with energy consumption. The authors also propose a way to cut down the DC-AC conversion loss. As a result, the system achieved a 30% reduction in carbon dioxide emissions in homes, and reduced costs. In addition, with the increased use of PV, the system also equalized electric-load. The authors also found that the new system improved PV power rate to 90%.
8
Felinto, Alan S., Cursino B. Jacobina, Edgard L. L. Fabricio, and Rodrigo P. de Lacerda. "Single DC-Link Three-phase AC-DC-AC Converter With Shared Legs." In 2019 IEEE Energy Conversion Congress and Exposition (ECCE). IEEE, 2019. http://dx.doi.org/10.1109/ecce.2019.8912998.
Full text
9
Zhang, Jianwei, Li Li, Tingting He, Mahlagha Mahdavi Aghdam, and David G. Dorrell. "Investigation of direct matrix converter working as a versatile converter (AC/AC, AC/DC, DC/AC, DC/DC conversion) with predictive control." In IECON 2017 - 43rd Annual Conference of the IEEE Industrial Electronics Society. IEEE, 2017. http://dx.doi.org/10.1109/iecon.2017.8216800.
Full text
10
Rodrigues, Phelipe L. S., Cursino B. Jacobina, and Antonio M. N. Lima. "Multilevel Single-Phase Four-Leg AC-DC-AC Converter." In 2020 IEEE Energy Conversion Congress and Exposition (ECCE). IEEE, 2020. http://dx.doi.org/10.1109/ecce44975.2020.9236315.
Full text