628 research outputs found

    Analysis of suitable converter for the implementation of drive system in solar photovoltaic panels

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    Introduction. Photovoltaic (PV) systems gained immense attraction in the recent years since it produces electricity without causing environmental pollution through direct conversion of solar irradiance into electricity. Solar PV panels produce DC power. The magnitude of this DC power varies with temperature and irradiance of the sun rays. The DC supply from solar panels can be regulated using DC-DC converter and then can further be converted into the desired AC voltage by means of a voltage source inverter before being fed to an induction motor (IM). The speed and torque of an IM, fed from PV arrays, can vary due to the variation in the output power of the panels. Goal of this work is to improve the dynamic performance and reduce the torque ripple of Cuk converter-inverter fed IM drive system. The novelty of the current work proposes interleaved Cuk converter between solar PV DC source and the inverter. Purpose. To provide continuous current using an interleaved Cuk converter to the IM drive and in turn to reduce the torque ripple in IM. Methodology. Introduced an interleaved Cuk converter which is a blend of Cuk converters connected in parallel with each other between solar PV arrays and IM drive system. Originality. Simulation results are obtained for Cuk converter and interleaved Cuk converter fed IM drive by means of MATLAB. The hardware setup for the same IM systems is developed. Practical value. Simulation and hardware results are coincided with each other and it is subject from the simulation and hardware results that the interleaved Cuk converter-inverter fed IM system produced results superior than the Cuk converter inverter fed IM drive system.Вступ. Фотоелектричні (ФЕ) системи набули величезної привабливості в останні роки, оскільки вони виробляють електроенергію, не викликаючи забруднення навколишнього середовища, за рахунок прямого перетворення сонячного випромінювання на електрику. Сонячні ФЕ панелі виробляють енергію постійного струму. Значення цієї потужності постійного струму залежить від температури та освітленості сонячних променів. Подача постійного струму від сонячних панелей може регулюватися за допомогою DC-DC перетворювача, а потім може бути перетворена в бажану змінну напругу за допомогою інвертора джерела напруги перед подачею на асинхронний двигун. Швидкість та обертаючий момент асинхронного двигуна, що живиться від ФЕ батарей, можуть змінюватися через зміну вихідної потужності панелей. Метою даної роботи є покращення динамічних характеристик та зменшення пульсацій обертаючого моменту системи приводу асинхронного двигуна з живленням від Cuk перетворювача-інвертора. Новизна цієї роботи пропонує Cuk перетворювач, що чергується, між сонячним ФЕ джерелом постійного струму та інвертором. Мета. Забезпечення безперервності струму за допомогою Cuk перетворювача, що чергується, для приводу асинхронного двигуна і, у свою чергу, зменшення пульсації обертаючого моменту в асинхронному двигуні. Методологія. Представлений Cuk перетворювач, що чергується, який являє собою суміш Cuk перетворювачів, підключених паралельно один до одного між сонячними ФЕ батареями і системою приводу асинхронного двигуна. Оригінальність. Результати моделювання отримані для Cuk перетворювача і приводу асинхронного двигуна з живленням Cuk перетворювача, що чергується, за допомогою MATLAB. Розроблено апаратну частину цих же асинхронних двигунів. Практична цінність. Результати моделювання та апаратного забезпечення збігаються один з одним, і з результатів моделювання та апаратного забезпечення випливає, що система асинхронного двигуна з живленням від Cuk перетворювача-інвертора, що чергується, дає результати, які перевищують результати, ніж система приводу асинхронного двигуна з живленням від Cuk перетворювача

    Magnetic Integration Techniques for Resonant Converters

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    This thesis sets out a series of new transformer topologies for magnetic integration in different resonant converters. Resonant converters like LLC converters require a high number of magnetic components, leading to low power density and high cost. These magnetic components can usually be integrated into a single transformer to increase power density, efficiency, manufacturing simplicity and to reduce cost. This strategy is known as integrated transformer (IT). The work described in this thesis has sought to deliver improvements in implementing this strategy. The benefits of resonant converters compared to pulse-width-modulated (PWM) converters are discussed. To show the drawbacks of PWM converters, two hard-switched DC-DC converters and two soft-switched DC-DC converters using state-of-the-art wide bandgap (WBG) gallium nitride devices are constructed and investigated. The LLC resonant converter is fully discussed for unidirectional and bidirectional applications. The different techniques for magnetic integration that can be applied to the LLC resonant converter are reviewed. Amongst these techniques, the inserted-shunt integrated transformers, which have gained popularity recently, are made a focus of the thesis. In general, the important challenges concerning the inserted-shunt integrated transformers are the need for bespoke material for the shunt, unwanted high leakage inductance on the secondary side, and that integrated magnetics are not usually suitable for bidirectional converters such as CLLLC converters. Two new topologies (IT1 and IT2) for inserted-shunt integrated transformers are presented that do not need bespoke material for the shunt and can be constructed from materials available commercially in large and small quantities. However, the manufacturing of these proposed topologies is challenging since magnetic shunts are made by joining several smaller magnetic pieces to form a segmented piece. A further new topology (IT3) is presented that not only does not need bespoke material for the shunt but also benefits from simple manufacturing. However, inserted-shunt integrated transformer, including all three proposed topologies (IT1-IT3), still suffer from increased leakage inductance on the secondary side, leading the control and design of the resonant converters to difficulty. Another topology (IT4) is therefore proposed that can be constructed easily with commercially available materials and does not increase the leakage inductance on the secondary side. However, all four proposed topologies (IT1-IT4) and other topologies with an inserted-shunt are not suitable for use in bidirectional LLC-type resonant converters when different primary and secondary leakage inductances are needed, such as where variable gain is required. Finally, a topology (IT5) is proposed that can be used in bidirectional LLC-type converters while it still benefits from simple manufacturing and using commercially available materials. All the proposed topologies (IT1-IT5) are discussed in detail and their design guidelines and modelling are provided. The theoretical analysis is confirmed by finite-element (FEM) analysis and experimental results. A unidirectional LLC resonant converter and a bidirectional CLLLC resonant converter are implemented to investigate the performance of the proposed integrated transformers (IT1-IT5) in practice. It is shown that the converters can operate properly while all their magnetic components are integrated into the proposed transformers

    Emerging Power Electronics Technologies for Sustainable Energy Conversion

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    This Special Issue summarizes, in a single reference, timely emerging topics related to power electronics for sustainable energy conversion. Furthermore, at the same time, it provides the reader with valuable information related to open research opportunity niches

    Efficiency Comparison of Asynchronous and Synchronous Buck Converter with Variation in Duty Cycle and Output Current

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    There are two most commonly used topologies in buck converter applications, asynchronous and synchronous buck converter. These two topologies have its own advantages and disadvantages from a performance point of view. The difference in performance, especially in the aspect of efficiency need to be addressed further, knowing the efficiency is a crucial aspect of buck converter application. In this study, the comparison of asynchronous and synchronous topology in terms of its efficiency will be analyzed using software simulation and hardware prototypes. Software simulation will be used to validate the workings of buck converter prototypes by comparing its characteristics against the hardware prototypes. Furthermore, the performance between both topologies will be analyzed under various operating conditions. Based on the results obtained in this study, when the applied duty cycle is low, for instance in 30% duty cycle and both converters operate at the lowest current, the asynchronous topology have a better efficiency of 19.15% against the synchronous topology, however, when both converters operate at the highest current, the synchronous topology shows its efficiency advantage of 6.56% against the asynchronous topology. On the other hand, in a higher duty cycle operation, for example in 80% duty cycle, both converters have an insignificant difference of efficiency

    A Multi-Inverter Multi-Rectifier Wireless Power Transfer System for Charging Stations With Power Loss Optimized Control

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    Electric vehicles with different output power levels can use wireless power transfer (WPT) systems. Different vehicle assemblies (VAs) may be charged by different ground assemblies (GAs) in charging stations. However, the overall efficiency of the WPT system may drop significantly when the power class difference between GA and VA is large. To address this issue this article proposes a dc-link parallel ac-link series multi-inverter multirectifier architecture for high-power WPT systems. Modulation, power transfer capability, and power sharing from the design aspects are investigated. A detailed power loss analysis and an easy-to-implemented power loss optimized control method based on mutual inductance identification are presented in this article. Finally, experimental results are obtained from a 20-kW LCC-LCC WPT system to validate the analysis and proposed system operation

    Capacitive power transfer for maritime electrical charging applications

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    Wireless power transfer can provide the convenience of automatic charging while the ships or maritime vehicles are docking, mooring, or in a sailing maneuver. It can address the challenges facing conventional wired charging technologies, including long charging and queuing time, wear and tear of the physical contacts, handling cables and wires, and electric shock hazards. Capacitive power transfer (CPT) is one of the wireless charging technologies that has received attention in on-road electric vehicle charging applications. By the main of electric fields, CPT offers an inexpensive and light charging solution with good misalignment performance. Thus, this study investigates the CPT system in which air and water are the separation medium for the electrical wireless charging of small ships and unmanned maritime vehicles. Unlike on-road charging applications, air or water can be utilized as charging mediums to charge small ships and unmanned maritime vehicles. Because of the low permittivity of the air, the air-gapped capacitive coupling in the Pico Farad range requires a mega-hertz operating frequency to transfer power over a few hundred millimeters. This study examines an air-gapped CPT system to transfer about 135 W at a separation distance of 50 mm, a total efficiency of approximately 83.9%, and a 1 MHz operating efficiency. At 13.56 MHz, the study tested a shielded air-gapped CPT system that transfers about 100 W at a separation distance of 30 mm and a total efficiency of about 87%. The study also examines the underwater CPT system by submerging the couplers in water to increase the capacitive coupling. The system can transfer about 129 W at a separation distance of 300 mm, a total efficiency of aboutapproximately%, and a 1.1 MHz operating efficiency. These CPT systems can upscale to provide a few kW for small ships and unmanned maritime vehicles. But they are still facing several challenges that need further investigations

    Review on unidirectional non-isolated high gain DC-DC converters for EV sustainable DC fast charging applications

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    Modern electrical transportation systems require eco-friendly refueling stations worldwide. This has attracted the interest of researchers toward a feasible optimal solution for electric vehicle (EV) charging stations. EV charging can be simply classified as Slow charging (domestic use), Fast charging and Ultrafast charging (commercial use). This study highlights recent advancements in commercial DC charging. The battery voltage varies widely from 36V to 900V according to the EVs. This study focuses on non-isolated unidirectional converters for off-board charging. Various standards and references for fast off-board charging have been proposed. Complete transportation is changed to EVs, which are charged by the grid supply obtained by burning natural fuels, contributing to environmental concerns. Sustainable charging from sustainable energy sources will make future EV completely eco-friendly transportation. The research gap in complete eco-friendly transit is located in interfacing sustainable energy sources and fast DC EV charging. The first step towards clean, eco-friendly transportation is identifying a suitable converter for bridging the research gap in this locality. A simple approach has been made to identify the suitable DC-DC converter for DC fast-charging EVs. This article carefully selected suitable topologies derived from Boost, SEPIC, Cuk, Luo, and Zeta converters for clean EV charging applications. A detailed study on the components count, voltage stress on the controlled and uncontrolled switches, voltage gain obtained, output voltage, power rating of the converters, switching frequency, efficiency obtained, and issues associated with the selected topologies are presented. The outcome of this study is presented as the research challenges or expectations of future converter topologies for charging

    Design and Advanced Model Predictive Control of Wide Bandgap Based Power Converters

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    The field of power electronics (PE) is experiencing a revolution by harnessing the superior technical characteristics of wide-band gap (WBG) materials, namely Silicone Carbide (SiC) and Gallium Nitride (GaN). Semiconductor devices devised using WBG materials enable high temperature operation at reduced footprint, offer higher blocking voltages, and operate at much higher switching frequencies compared to conventional Silicon (Si) based counterpart. These characteristics are highly desirable as they allow converter designs for challenging applications such as more-electric-aircraft (MEA), electric vehicle (EV) power train, and the like. This dissertation presents designs of a WBG based power converters for a 1 MW, 1 MHz ultra-fast offboard EV charger, and 250 kW integrated modular motor drive (IMMD) for a MEA application. The goal of these designs is to demonstrate the superior power density and efficiency that are achievable by leveraging the power of SiC and GaN semiconductors. Ultra-fast EV charging is expected to alleviate the challenge of range anxiety , which is currently hindering the mass adoption of EVs in automotive market. The power converter design presented in the dissertation utilizes SiC MOSFETs embedded in a topology that is a modification of the conventional three-level (3L) active neutral-point clamped (ANPC) converter. A novel phase-shifted modulation scheme presented alongside the design allows converter operation at switching frequency of 1 MHz, thereby miniaturizing the grid-side filter to enhance the power density. IMMDs combine the power electronic drive and the electric machine into a single unit, and thus is an efficient solution to realize the electrification of aircraft. The IMMD design presented in the dissertation uses GaN devices embedded in a stacked modular full-bridge converter topology to individually drive each of the motor coils. Various issues and solutions, pertaining to paralleling of GaN devices to meet the high current requirements are also addressed in the thesis. Experimental prototypes of the SiC ultra-fast EV charger and GaN IMMD were built, and the results confirm the efficacy of the proposed designs. Model predictive control (MPC) is a nonlinear control technique that has been widely investigated for various power electronic applications in the past decade. MPC exploits the discrete nature of power converters to make control decisions using a cost function. The controller offers various advantages over, e.g., linear PI controllers in terms of fast dynamic response, identical performance at a reduced switching frequency, and ease of applicability to MIMO applications. This dissertation also investigates MPC for key power electronic applications, such as, grid-tied VSC with an LCL filter and multilevel VSI with an LC filter. By implementing high performance MPC controllers on WBG based power converters, it is possible to formulate designs capable of fast dynamic tracking, high power operation at reduced THD, and increased power density

    Selected Papers from 2020 IEEE International Conference on High Voltage Engineering (ICHVE 2020)

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    The 2020 IEEE International Conference on High Voltage Engineering (ICHVE 2020) was held on 6–10 September 2020 in Beijing, China. The conference was organized by the Tsinghua University, China, and endorsed by the IEEE Dielectrics and Electrical Insulation Society. This conference has attracted a great deal of attention from researchers around the world in the field of high voltage engineering. The forum offered the opportunity to present the latest developments and different emerging challenges in high voltage engineering, including the topics of ultra-high voltage, smart grids, and insulating materials

    Emerging Power Electronics Technologies for Sustainable Energy Conversion

    Get PDF
    This Special Issue summarizes, in a single reference, timely emerging topics related to power electronics for sustainable energy conversion. Furthermore, at the same time, it provides the reader with valuable information related to open research opportunity niches
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