A Reconfigurable Two-stage 11kW DC-DC Resonant Converter for EV Charging with a 150-1000V Output Voltage Range

In this paper, a reconfigurable two-stage DC/DC resonant topology with a wide output voltage range of 150-1000V is proposed for Electric Vehicle (EV) charging with high efficiency over the entire load range. The proposed topology consists of an LLC resonant converter with dual secondary sides; two interleaved triangular current mode buck converters, and three additional auxiliary switches for reconfiguration. Two possible arrangements of the proposed topology are considered and compared. The analytical model of the topology is developed, which is used for the efficiency estimation of different configurations and the design of the prototype converter. An 11kW hardware demonstrator is built and tested. The maximum measured efficiency of the converter is 97.66%, with a &gt;95% efficiency over the complete 150-1000V range at full power. The proposed two-stage converter achieves the widest output voltage range reported in literature for resonant power converters, thereby capable of charging existing and future EVs very efficiently over any charging cycle.</p

Integrated DC-DC Charger Powertrain Converter Design for Electric Vehicles Using Wide Bandgap Semiconductors

Electric vehicles (EVs) adoption is growing due to environmental concerns, government subsidies, and cheaper battery packs. The main power electronics design challenges for next-generation EV power converters are power converter weight, volume, cost, and loss reduction. In conventional EVs, the traction boost and the onboard charger (OBC) have separate power modules, passives, and heat sinks. An integrated converter, combining and re-using some charging and powertrain components together, can reduce converter cost, volume, and weight. However, efficiency is often reduced to obtain the advantage of cost, volume, and weight reduction.An integrated converter topology is proposed to combine the functionality of the traction boost converter and isolated DC-DC converter of the OBC using a hybrid transformer where the same core is used for both converters. The reconfiguration between charging and traction operation is performed by the existing Battery Management System (BMS) contactors. The proposed converter is operated in both boost and dual active bridge (DAB) mode during traction operation. The loss mechanisms of the proposed integrated converter are modeled for different operating modes for design optimization. An aggregated drive cycle is considered for optimizing the integrated converter design parameters to reduce energy loss during traction operation, weight, and cost. By operating the integrated converter in DAB mode at light-load and boost mode at high-speed heavy-load, the traction efficiency is improved. An online mode transition algorithm is also developed to ensure stable output voltage and eliminate current oscillation during the mode transition. A high-power prototype is developed to verify the integrated converter functionality, validate the loss model, and demonstrate the online transition algorithm. An automated closed-loop controller is developed to implement the transition algorithm which can automatically make the transition between modes based on embedded efficiency mapping. The closed-loop control system also regulates the integrated converter output voltage to improve the overall traction efficiency of the integrated converter. Using the targeted design approach, the proposed integrated converter performs better in all three aspects including efficiency, weight, and cost than comparable discrete solutions for each converter

CARGADOR DE BATERÍAS TRIFÁSICO CON ALTO FACTOR DE POTENCIA PARA VEHÍCULOS ELÉCTRICOS (THREE-PHASE BATTERY CHARGER WITH HIGH POWER FACTOR FOR ELECTRIC VEHICLES)

Resumen Con el avance de la tecnología se hace más notorio el uso de vehículos eléctricos que constituyen grandes cargas a la red eléctrica y requieren procesos de carga eficientes y con alto factor de potencia. En este artículo se propone un cargador de baterías trifásico constituido por un puente activo doble, un rectificador y un filtro, constituyendo un corrector del factor de potencia operando en modo de conducción discontinua. Para evaluar el desempeño se realizaron simulaciones en lazo cerrado del sistema propuesto, donde se aprecian las bondades del sistema. Palabras Clave: Cargador de baterías trifásico, vehículos eléctricos, factor de potencia, puente activo doble. Abstract The advancement of technology, the use of electric vehicles is increasing and they may constitute a large load in the electrical grid, they require efficient charging processes with high power factor. This work proposes a three-phase battery charger based on a double active bridge, a rectifier, and a filter; with a high power factor since it is operated in discontinuous conduction mode. The performance of the system is evaluated by close loop simulation, where the performance of the system is illustrated. Keywords: Three-phase battery charger, electric vehicles, power factor, double active bridge

E-Mobility -- Advancements and Challenges

Mobile platforms cover a broad range of applications from small portable electric devices, drones, and robots to electric transportation, which influence the quality of modern life. The end-to-end energy systems of these platforms are moving toward more electrification. Despite their wide range of power ratings and diverse applications, the electrification of these systems shares several technical requirements. Electrified mobile energy systems have minimal or no access to the power grid, and thus, to achieve long operating time, ultrafast charging or charging during motion as well as advanced battery technologies are needed. Mobile platforms are space-, shape-, and weight-constrained, and therefore, their onboard energy technologies such as the power electronic converters and magnetic components must be compact and lightweight. These systems should also demonstrate improved efficiency and cost-effectiveness compared to traditional designs. This paper discusses some technical challenges that the industry currently faces moving toward more electrification of energy conversion systems in mobile platforms, herein referred to as E-Mobility, and reviews the recent advancements reported in literature

Transformer Volume Reduction: A New Analysis and Design of an SSSA Control Based 20kW High Power Density Wide Range Resonant Converter

Isolated DC/DC converters play a pivotal rolein the realm of power electronics, particularly in the contextof electric vehicle (EV) fast charging. These converters areresponsible for delivering high-voltage direct current toEVs, sourced from a 3-phase power factor correction (PFC)converter, and exhibit compatibility with both low-voltageand high-voltage vehicle batteries. However, in manyinstances, the demand for constant power charging invarious applications results in a significant portion of thetransformer volume, thereby leading to a decrease inconverter power density. This paper presents a newanalysis and design for a converter based on secondaryside semi-active (SSSA) control. This analysis providestheoretical support for transformer volume reduction andpower density increase. It employs SSSA control totransfer stored energy from the transformer to the resonantnetwork during boost operation, even when fs &gt; fr, with theexcitation inductance participating in resonance. Based onthis analysis, the design of a 20kW 650-850V input to300-900V with 66.7A max output prototype is discussed.The objective is to achieve the highest feasible converterpower density. The designed results confirm that the2*PQ6535 (or 1*PQ6549) core can effectively serve the20kW transformer, resulting in an ultra-high power densityof 14.36 kW/L (235 W/in3)

Propulsion-Machine-Integrated Universal Onboard Chargers for Electric Vehicles

Onboard level-1 and level-2 battery chargers are widely utilized in electric vehicles (EVs) for home overnight or office daytime charging. However, onboard level-1 and level-2 chargers suffer from power limitations and long charging time. On the other hand, high-power off-board chargers are utilized for fast charging, but they are bulky, expensive and require comprehensive evolution of charging infrastructures. Onboard chargers integrated with the propulsion systems of EVs provide a promising solution for fast charging of EV battery packs without contributing to additional weight and burden on the vehicle. This dissertation presents integrated charging systems, using the propulsion machine and its inverter for onboard battery charging. The proposed integrated onboard chargers do not need any modification of the propulsion systems to implement onboard battery charging. The integrated charging approaches are highly practical and applicable for commercial EVs in market. Initially, a single-phase propulsion-machine-integrated onboard charger is introduced and developed, which is capable of power factor correction (PFC) and battery voltage/current regulation without any bulky add-on passive components. The machine windings are utilized as mutually coupled inductors for PFC, and the inverter along with the machine windings constructs a two-channel interleaved boost converter. The input current ripple cancellation effect of the interleaved circuit is analyzed in detail, and the operation principles of the charging systems are presented. The feasibility of the single-phase integrated charger is proved by experimental results. Then, two approaches for three-phase propulsion-machine-integrated onboard charging are introduced and investigated. In the first approach, the charger topology is composed of a three-phase six-switch power electronics interface and the propulsion system. The proposed interface, mainly consisting of semiconductors, has small size and high power density, enabling onboard installment. The detailed operation modes of the topology are presented. In addition, the control-oriented modeling of the charging system is conducted, and a control system is designed to enable both the unity PFC and the battery voltage/current regulation. A 3.3kW prototype is designed, developed and tested for the validation of the proposed concept. The second approach is based on a three-phase three-switch power electronics interface, which is intended to be an even smaller interface. The power density of the three-switch interface increases by 40% in comparison to the first approach. The modeling and control strategy of the charging system are investigated and presented. A 5kW prototype is designed and built to validate the charging system and its control strategy

Design and Analysis of Reconfigurable Resonant Converter with Ultra Wide Output Voltage Range

In this article, a reconfigurable isolated dc/dc converter is proposed suitable for a wide output voltage range of 180–1500 V for efficient onshore charging in maritime applications. The proposed circuit concept can also fulfill the requirements of other heavy-duty battery charging applications, especially those operating within the shore environment—such as straddle carriers, forklifts, reach stackers, and terminal tractors. The circuit topology consists of two interleaved LLC resonant converters each connected to a three-winding transformer. Through the use of additional circuitry, the topology can be adapted to operate at peak efficiency in three output voltage ranges. Furthermore, the topology is able to alleviate the current and voltage stresses on the semiconductor devices in comparison to the conventionally employed LLC resonant converters. The operation of the circuit is explained and its steady-state model is developed. In order to validate the performance of the converter, an 11-kW prototype is designed, tested, and analyzed. The experimental results attest that the proposed reconfigurable resonant converter is able to achieve an extremely wide output voltage range while maintaining a high power transfer efficiency

Sistema de gerenciamento de energia elétrica para integração de veículo elétrico e microrrede

Orientador:Prof. Dr. Alexandre Rasi AokiDissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia Elétrica. Defesa : Curitiba, 20/10/2021Inclui referências: p. 95-100Área de concentração: Sistemas de EnergiaResumo: Com a esperada integração dos veículos elétricos a frota de veículos, o setor de transportes passara por profundas transformações. Uma das principais mudanças será a mudança de paradigma na estrutura de energia elétrica no modelo atual. Essa mudança tem sido aceita pela sociedade, em termos ecológicos, mas traz consigo grandes desafios para os sistemas de distribuição de energia. Esses veículos precisarão ser recarregados, por exemplo, em corrente alternada no modo residencial na maior parte do tempo. A quantidade extra de energia exigida nesta operação pode levar a diversos problemas operacionais nas redes de geração, transmissão e distribuição. Para promover o sucesso da implementação deste novo modo de transporte e evitar problemas operacionais, soluções de recarga coordenadas com a geração de energia renovável são adaptadas as necessidades que começam a surgir. Dessa forma, eles devem ser o mais simples possível e não devem ser percebidos como novos investimentos para a rede de distribuição e também aos donos de veículos elétricos que se utilizam dessa infraestrutura de recarga. Assim, foi projetado e implementado em uma residência na cidade de Curitiba-PR, uma estação de recarga real em corrente alternada para veículos elétricos que possui geração fotovoltaica, armazenamento local por baterias em sistema de microrrede e o controle do despacho de energia através de dispositivo IoT. O algoritmo que controla o despacho de energia foi desenvolvido usando linguagem ARDUINO como base. O método de despacho de energia controlado pelo algoritmo e baseado no estado de carga do armazenamento local. Alem disso, esse algoritmo também monitora o momento em que a tensão de pico da rede local passa por zero para comandar a comutação entre as diferentes fontes de energia disponíveis. Quatro cenários básicos foram simulados e comparados entre si para mostrar o desempenho e efetividade do método apresentado. Esses cenários são em modo ilhado, modo misto, conectado e também um cenário em regime de tarifa branca que trata do processo de recarga em horários específicos do dia. A aplicação desse método durante o mês de analise, trouxe uma eficiência nos valores de energia elétrica não consumida da rede de distribuição local para a residência e também favoreceu a recarga em uma faixa de horários de ponta específica do dia.Abstract: With the expected integration of electric vehicles into the vehicle fleet, the transport sector will undergo profound changes. One o f the main changes will be the paradigm shift in the structure o f electricity in the current model. This change has been accepted by society, in ecological terms, but it brings with it great challenges for energy distribution systems. These vehicles will need to be recharged, for example, in alternating current in residential mode most o f the time. The extra amount o f energy required in this operation can lead to several operational problems in the generation, transmission and distribution networks. To promote the successful implementation of this new mode of transport and avoid operational problems, recharge solutions coordinated with the generation o f renewable energy are adapted to the needs that are beginning to emerge. Therefore, they should be as simple as possible and should not be seen as new investments for the distribution network and also for owners of electric vehicles that use this charging infrastructure. Thus, it was designed and implemented in the city of Curitiba-PR, in a regular house, a real alternating current charging station for electric vehicles that count with photovoltaic generation, battery storage system all connected in a microgrid way and a energy dispatch control that uses an loT device. The algorithm that runs on loT device and controls the energy dispatch was developed using ARDUINO. These control energy dispatch method is based according to the state of charge o f the local storage and also monitors the moment when the local power network peaking voltage crossing to zero to start the switching process between available energy resources. Four basic scenarios were simulated and compared to each other to show the performance and effectiveness of the presented method. These scenarios are in island mode, mixed mode, connected and also a scenario in a white tariff regime that deals with the recharge process at specific times o f the day. The application of this method during the month of analysis, brought an efficiency in the values o f electricity not consumed from the local distribution network to the home and also favored charging at a specific peak hour range of the day