A simplified control scheme for electric vehicle- power grid circuit with DC distribution and battery storage systems

Abstract: Direct current (DC) system is becoming the major trend for future internal power grid of electric vehicles (EVs). Since DC power grid system has a different nature to conventional alternating current (AC) grid system, appropriate design of the controller for EV- grid circuit is mandatory. In this paper, an EV employing a pure DC grid circuit with battery storage system (BSS) is considered as a study case. To enable a more efficient use of BSS, a flyback DC-DC converter for batteries charger/or discharger strategy is selected, which satisfy the power flows requirements. The dynamic and control performances of the combined system, i.e. “BSS- flyback DC-DC converter- connected to a DC motor”, is investigated in terms of voltage/ current signal fluctuations. The small-signal based control method is used, which limits the small-signal variations to about zero. To verify the effectiveness of the control strategy several simulations are done using Matlab. The simulation results illustrate the performances obtained

Fuzzy PD+I Embedded Control System for a Multi-Phase DC-DC Bidirectional Converter

[EN] In this work is presented the design of a Fuzzy PD+I control system applied to the voltage control of a multi-phase DC-DC power electronic converter. The fuzzy controller has two inputs. The first input, named Error, is the difference between the desired voltage value in the output of the converter and the measured voltage at this particular point; the second input is defined by the changes in the measured voltage of the converter. The control system is embedded in the NI myRIO-1900 development kit, using LabVIEW as programming software employing the embedded system for experimental tests with a prototype of the converter. This control system allows the stabilization of the converter in the buck and boost operation modes, showing an appropriate behavior at the startup and under resistive load changes, presenting acceptable times for DC microgrids future applications while connecting the DC bus with supercapacitors or a battery bank.[ES] En este trabajo se presenta el diseño de un sistema de control difuso PD+I embebido aplicado en el control de voltaje de un convertidor electrónico de potencia bidireccional multi-fase CD-CD. El controlador difuso cuenta con dos entradas, la primera se le denomina Error y es la diferencia entre el valor de voltaje deseado en la salida del convertidor y el voltaje medido en la salida del mismo; la segunda entrada es definida por las variaciones en el voltaje medido. La salida del controlador difuso define las variaciones en el ciclo de trabajo de los interruptores de potencia que controlan el convertidor. El sistema de control difuso se embebió en la tarjeta de desarrollo NI myRIO-1900 utilizando como software de programación LabVIEW, empleando el sistema embebido para realizar pruebas experimentales con el prototipo del convertidor. Con este sistema de control de voltaje se logra estabilizar el convertidor en los modos de operación reductor y elevador, demostrando un adecuado comportamiento del convertidor en el arranque y ante cambios de carga resistiva, manteniendo tiempos aceptables para aplicaciones futuras en micro-redes de CD conectando el bus de CD con un banco de super-capacitores o un banco de baterías.Martínez Nolasco, JJ.; Rodríguez, E.; Rodríguez, H.; Morfin, J.; Padilla, A. (2018). Fuzzy PD+I Embedded Control System for a Multi-Phase DC-DC Bidirectional Converter. Revista Iberoamericana de Automática e Informática industrial. 15(4):457-466. https://doi.org/10.4995/riai.2018.8721OJS457466154Baek J. B., Choi, W. I., Cho, B. H., 2013. Digital adaptive frequency modulation for bidirectional DC-DC converter. IEEE Transactions on Industrial Electronics, 60(11), 5167-5176. DOI: 10.1109/TIE.2012.2224075Bolognani S., Morandin M., Calligaro S., Petrella R., Pevere A., 2014. Bidirectional PMSM drive employing a three level ANPC inverter and a multi-phase interleaved DC/DC converter for hybrid electric vehicles. Twenty-Ninth Annual IEEE in Applied Power Electronics Conference and Exposition (APEC), IEEE, 818-825. DOI: 10.1109/APEC.2014.6803402Brox M., Sánchez S., del Toro E., Brox P., Moreno F. J., 2013. CAD tools for hardware implementation of embedded fuzzy systems on FPGAs. IEEE Transactions on Industrial Informatics, 9(3), 1635-1644. DOI: 10.1109/TII.2012.2228871Burrett R., Clini C., Dixon R., Eckhart M., El-Ashry M., Gupta D., Houssin D., 2009. Renewable Energy Policy Network for the 21st Century.Dusmez S., Hasanzadeh A., Khaligh A., 2015. Comparative analysis of bidirectional three-level DC-DC converter for automotive applications. IEEE Transactions on Industrial Electronics, 62(5), 3305-3315. DOI: 10.1109/TIE.2014.2336605Hart D., 2011. Power Electronics, 1ra ed., McGraw-Hill, New York. 198-220.Hegazy O., Van Mierlo J., Lataire P., 2011. Design and control of bidirectional DC/AC and DC/DC converters for plug-in hybrid electric vehicles. International Conference in Power Engineering, Energy and Electrical Drives (POWERENG), IEEE, 1-7. DOI: 10.1109/PowerEng.2011.6036530Hossain M. I., Khan S. A., Shafiullah M., Hossain M. J. 2011. Design and implementation of MPPT controlled grid connected photovoltaic system. Symposium in Computers & Informatics (ISCI), IEEE, 284-289. DOI: 10.1109/ISCI.2011.5958928Khan S. A., Hossain M. I., 2010. Design and implementation of microcontroller based fuzzy logic control for maximum power point tracking of a photovoltaic system. International Conference in Electrical and Computer Engineering (ICECE), IEEE, 322-325. DOI: 10.1109/ICELCE.2010.5700693Kumar A., Gaur P., 2014. Bidirectional DC/DC converter for hybrid electric vehicle. International Conference in Advances in Computing, Communications and Informatics (ICACCI), IEEE, 839-843. DOI: 10.1109/ICACCI.2014.6968295Lee S. Y., Pfaelzer A. G., van Wyk, J. D., 2004. Thermal analysis for improved packaging of 4-channel 42 V/14 V DC/DC converter. 39th IAS Annual Meeting in Industry Applications Conference Vol. 4, IEEE, 2330-2336. DOI: 10.1109/IAS.2004.1348800Lee S. Y., Pfaelzer A. G., van Wyk J. D., 2007. Comparison of different designs of a 42-V/14-V dc/dc converter regarding losses and thermal aspects. IEEE Transactions on Industry Applications, 43(2), 520-530. DOI: 10.1109/TIA.2006.889808Liu D., Hu A., Wang G., Hu W., 2010. Current sharing schemes for multiphase interleaved DC/DC converter with FPGA implementation. International Conference in Electrical and Control Engineering (ICECE), IEEE, 3512-3515. DOI: 10.1109/iCECE.2010.854Markvart T., 2006. Microgrids: Power systems for the 21st century. Refocus, 7(4), 44-48.Martínez, J. J., Padilla-Medina, J. A., Cano-Andrade, S., Sancen, A., Prado, J., & Barranco, A. I. (2018). Development and Application of a Fuzzy Control System for a Lead-Acid Battery Bank Connected to a DC Microgrid. International Journal of Photoenergy, 2018.Omara A. M., Sleptsov M. A., 2016. Comparative study of different electric propulsion system configurations based on IPMSM drive for battery electric vehicles. International Conference in Electrical Machines and Systems (ICEMS), IEEE, 1-6.Sánchez S., Cabrera A., Baturone M. I., Moreno F. J., Brox M., 2007. FPGA implementation of embedded fuzzy controllers for robotic applications. IEEE Transactions on Industrial Electronics, 54(4), 1937-1945. DOI: http://dx.doi.org/10.1109/TIE.2007.898292Santos M., 2011. Un enfoque aplicado del control inteligente. Revista Iberoamericana de Automática e Informática Industrial RIAI, 8(4), 283-296. DOI: 10.1016/j.riai.2011.09.016Sikkabut S., Mungporn P., Ekkaravarodome C., Bizon N., Tricoli P., Nahid-Mobarakeh B., Thounthong P., 2016. Control of High-Energy High-Power Densities Storage Devices by Li-ion Battery and Supercapacitor for Fuel Cell/Photovoltaic Hybrid Power Plant for Autonomous System Applications. IEEE Transactions on Industry Applications, 52(5), 4395-4407. DOI: 10.1109/TIA.2016.2581138Thao N. G. M., Dat M. T., Binh T. C., Phuc N. H., 2010. PID-fuzzy logic hybrid controller for grid-connected photovoltaic inverters. International Forum in Strategic Technology (IFOST), IEEE, 140-144. DOI: 10.1109/IFOST.2010.5668024Vanti V. M., Leite L. C., Batista E. A., 2015. Monitoring and control of the processes involved in the capture and filtering of biogas using FPGA embedded fuzzy logic. IEEE Latin America Transactions, 13(7), 2232-2238. DOI: 10.1109/TLA.2015.7273782Yang Y., Li T., Liu J., Li H., 2012. A comprehensive analysis of coupled inductors in 4 phases interleaving bidirectional DC/DC converter. International Symposium in Power Electronics for Distributed Generation Systems (PEDG), IEEE, 603-607. DOI: 10.1109/PEDG.2012.6254064Yang Y., Ma J., Ma Y., Zou Y., 2014. The universal design criterion of coupled inductor in multiphase interleaving and magnetically integrated bidirectional DC/DC converter. Conference and Exposition International in Power Electronics and Application, IEEE, 1008-1013. DOI: 10.1109/PEAC.2014.7037998Yang Y., Dai S., 2015. Design criterion for asymmetric coupled inductors in interleaving & magnetically integrated bidirectional DC/DC converter. 2nd Conference International in Future Energy Electronics, IEEE, 1-11. DOI: 10.1109/IFEEC.2015.7361443Yu, B. (2016). Design and experimental results of battery charging system for microgrid system. International Journal of Photoenergy, 2016

Technology Maturity Roadmaps of Power System Components for eVTOL Aircraft

The viability of aerial taxi missions is highly dependent on the mass and reliability of the electrical power system to supply uninterrupted power to the propulsion [1–3]. Yet, the electrical power system is limited by the low maturity, in terms of power and energy density, of the current available critical technologies. Therefore, the integration of the technologies into a single power and propulsion system requires significant attention to provide a viable solution capable of supporting the mission requirements. Following from this, there is a clear need for a consolidated capture and project of relevant electrical technology capability and availability in order to develop effective solutions. This white paper presents a summary and discussion of 10-year roadmaps for key electrical technologies required for electrical vertical take-off and landing (eVTOL) aircraft design. The technologies covered are critical to the power system design and include energy storage, power electronics, power machines, and protection devices. Power-to-weight and energy-to-weight ratios have been obtained from public domain sources on existing technologies, market projections, and projection targets from advisory bodies in order to establish technology progression trendlines. These can subsequently be used to influence electrical power and propulsion system design choices and strategies for future platforms

A Comprehensive Review of DC-DC Converters for EV Applications

DC-DC converters in Electric vehicles (EVs) have the role of interfacing power sources to the DC-link and the DC-link to the required voltage levels for usage of different systems in EVs like DC drive, electric traction, entertainment, safety and etc. Improvement of gain and performance in these converters has a huge impact on the overall performance and future of EVs. So, different configurations have been suggested by many researches. In this paper, bidirectional DC-DC converters (BDCs) are divided into four categories as isolated-soft, isolated-hard, non-isolated-soft and non-isolated-hard depending on the isolation and type of switching. Moreover, the control strategies, comparative factors, selection for a specific application and recent trends are reviewed completely. As a matter of fact, over than 200 papers have been categorized and considered to help the researchers who work on BDCs for EV application

Power Electronics Intensive Energy Management Solutions for Hybrid Electric Vehicle Energy Storage Systems

Batteries, ultra capacitors (UCs), and fuel cells (FCs) are widely being proposed for electric and plug-in hybrid electric vehicles (EVs/PHEVs) as energy sources. The increasing popularity of EVs and PHEVs can be attributed to the savings in fuel costs, compared to conventional internal combustion engine (ICE) vehicles. EVs and PHEVs save energy due to the employment of reverse regenerating braking, during the deceleration cycle. This recuperated energy can be proficiently stored in batteries and/or ultra-capacitors. In general, the design of an intelligent control strategy for coordinated power distribution is a critical issue for ultra-capacitor supported PHEV energy storage systems. Implementation of several control methods have been presented in related literature, with the goal of improving battery life and overall vehicle efficiency. The control objectives vary with respect to vehicle velocity, power demand, and state-of-charge of both the batteries and ultra-capacitors. Hence, an optimal control strategy design is a critical aspect of an all-electric/plug-in hybrid electric vehicle operational characteristic. This thesis deals with the detailed analysis and novel hybrid controller design for bidirectional energy management solutions, using smart power electronic DC/DC converter solutions. More specifically, an intelligently designed novel digital control technique is presented for a 4-quadrant switched-capacitor Luo (4Q SC Luo) DC/DC converter. Features of voltage step-down, step-up, and bi-directional power flow are integrated into a single circuit. The novel control strategy enables simpler dynamics, compared to a standard buck converter with input filter, superior regulation capability, lower source current ripple, ease of control, and continuous input current waveform in buck and boost modes of operation. Furthermore, the proposed novel control strategy depicts high converter power density, high efficiency, and simple structure

Conversão de uma mota 4 TRX 250 da Honda em elétrica

Dissertação de mestrado. Mestrado Integrado em Engenharia Mecânica. Faculdade de Engenharia. Universidade do Porto. 201

Resilient power and propulsion system design for eVTOL aircraft

The continuous increase in population in megacities has led to a more pronounced issue of road congestion. Electrical vertical take-off and landing (eVTOL) aircraft have been proposed as a solution to alleviate road congestion by enabling greener and quieter aviation, providing a more time-efficient commuting option compared to helicopters. However, the realization of innovative eVTOL aircraft heavily relies on advancements in high-power and energy-dense power system technologies for lightweight electrical power systems (EPS). The limited maturity of lightweight EPS technologies and their safe integration into the aircraft pose challenges in terms of payload capacity and achievable range for eVTOL aircraft. This significantly impacts the performance of fully electric eVTOL aircraft for Urban Air Mobility (UAM) missions. Therefore, it is crucial to explore innovative approaches and new technologies for optimized EPS architecture and aerodynamic design at an early stage of the design process to achieve economical flight for UAM. These unique attributes of eVTOL aircraft differ significantly from conventional aircraft technologies and systems, emphasizing the need for a comprehensive understanding of aerodynamic-electrical failure interdependencies and EPS protection methodology to ensure a reliable EPS Therefore, the main research contributions of this thesis include the development of a novel design methodology to capture a certification-compliant EPS architecture for an eVTOL at the preliminary design phase. This methodology integrates mission requirements, aircraft aerodynamics, projected future availability of EPS technologies, and safety requirements. The development of the EPS architecture is carried out in parallel to the design of non-electrical systems to ensure future compliance with certification requirements. The methodology enables the identification of key design trades that minimise EPS system weight while ensuring that baseline safety criteria are met and future compliance with certification requirements. The results show that incorporating safety measures at a later stage will have a snowball effect on the aircraft design to meet certification requirements or stay within design constraints, such as weight. Furthermore, a novel abstract design methodology was developed to enable critical assessment of different aircraft aerodynamic configurations and explore new design spaces and novel architecture options. This methodology summarizes the relationship between aircraft aerodynamics and EPS requirements in a readily usable format. By combining the preliminary design methodology for a certification-compliant EPS architecture with the abstract design methodology, the complete assessment of various aircraft configurations and reliable EPS architecture designs and their weight for economic UAM missions can be achieved. Other main contributions of this thesis include the development of a preliminary certification compliance assessment for the use of non-resettable protection devices, specifically the Pyrofuse protection device, in eVTOL concept designs. The non-resettable nature of the device poses a challenge in the certification process for its integration into eVTOL electrical system protection. The assessment results demonstrate that the Pyrofuse protection device can achieve airworthiness in various roles as the primary protection for eVTOL EPS. However, the airworthiness is heavily influenced by the physical design of the aircraft, the proposed location of non-resettable protection devices, and their ability to withstand common mode and common cause failures to maintain minor failures. Model-based analysis plays a critical role in supporting this evaluation. Consequently, a comprehensive design methodology has been developed to transiently model Pyrofuse operation, which is publicly available. The results indicate that the Pyrofuse offers a significant level of resilience against transient events, minimising nuisance-tripping, while swiftly clearing short circuit faults. This model enables further assessment of Pyrofuse performance and susceptibility to different failure modes, including common mode failures.The continuous increase in population in megacities has led to a more pronounced issue of road congestion. Electrical vertical take-off and landing (eVTOL) aircraft have been proposed as a solution to alleviate road congestion by enabling greener and quieter aviation, providing a more time-efficient commuting option compared to helicopters. However, the realization of innovative eVTOL aircraft heavily relies on advancements in high-power and energy-dense power system technologies for lightweight electrical power systems (EPS). The limited maturity of lightweight EPS technologies and their safe integration into the aircraft pose challenges in terms of payload capacity and achievable range for eVTOL aircraft. This significantly impacts the performance of fully electric eVTOL aircraft for Urban Air Mobility (UAM) missions. Therefore, it is crucial to explore innovative approaches and new technologies for optimized EPS architecture and aerodynamic design at an early stage of the design process to achieve economical flight for UAM. These unique attributes of eVTOL aircraft differ significantly from conventional aircraft technologies and systems, emphasizing the need for a comprehensive understanding of aerodynamic-electrical failure interdependencies and EPS protection methodology to ensure a reliable EPS Therefore, the main research contributions of this thesis include the development of a novel design methodology to capture a certification-compliant EPS architecture for an eVTOL at the preliminary design phase. This methodology integrates mission requirements, aircraft aerodynamics, projected future availability of EPS technologies, and safety requirements. The development of the EPS architecture is carried out in parallel to the design of non-electrical systems to ensure future compliance with certification requirements. The methodology enables the identification of key design trades that minimise EPS system weight while ensuring that baseline safety criteria are met and future compliance with certification requirements. The results show that incorporating safety measures at a later stage will have a snowball effect on the aircraft design to meet certification requirements or stay within design constraints, such as weight. Furthermore, a novel abstract design methodology was developed to enable critical assessment of different aircraft aerodynamic configurations and explore new design spaces and novel architecture options. This methodology summarizes the relationship between aircraft aerodynamics and EPS requirements in a readily usable format. By combining the preliminary design methodology for a certification-compliant EPS architecture with the abstract design methodology, the complete assessment of various aircraft configurations and reliable EPS architecture designs and their weight for economic UAM missions can be achieved. Other main contributions of this thesis include the development of a preliminary certification compliance assessment for the use of non-resettable protection devices, specifically the Pyrofuse protection device, in eVTOL concept designs. The non-resettable nature of the device poses a challenge in the certification process for its integration into eVTOL electrical system protection. The assessment results demonstrate that the Pyrofuse protection device can achieve airworthiness in various roles as the primary protection for eVTOL EPS. However, the airworthiness is heavily influenced by the physical design of the aircraft, the proposed location of non-resettable protection devices, and their ability to withstand common mode and common cause failures to maintain minor failures. Model-based analysis plays a critical role in supporting this evaluation. Consequently, a comprehensive design methodology has been developed to transiently model Pyrofuse operation, which is publicly available. The results indicate that the Pyrofuse offers a significant level of resilience against transient events, minimising nuisance-tripping, while swiftly clearing short circuit faults. This model enables further assessment of Pyrofuse performance and susceptibility to different failure modes, including common mode failures

Desenvolvimento de um conversor CC-CC bidirecional isolado para um sistema load-shift

Dissertação de mestrado em Engenharia Eletrónica Industrial e ComputadoresO uso de energia elétrica é cada vez mais inevitável na realização das tarefas mais importantes ou rotineiras do dia-a-dia da maioria das pessoas. Para colmatar o aumento da demanda de energia elétrica, evitando problemas ambientais, tem-se vindo a apostar, cada vez mais, na produção de energia elétrica a partir de fontes de energia renovável. No entanto, algumas fontes de energia renovável, nomeadamente a solar e a eólica, apresentam como desvantagem a intermitência na produção. Além disso, esta situação é ainda mais agravada devido ao facto de os períodos de maior produção dessas fontes de energia renovável coincidirem, na maioria dos casos, com os períodos de menor procura de energia elétrica. Apesar da existência de incentivos para o consumo da energia elétrica nos períodos em que a procura é mais baixa, na maioria dos casos, isso não é praticável. Assim, para reforçar a utilização das fontes de energia renovável e o aproveitamento dos incentivos referentes aos períodos de menor procura, surgem novas oportunidades relativas à evolução dos sistemas de armazenamento e gestão da energia elétrica. Apesar dos sistemas Load-Shift poderem ser associados a vários conceitos distintos, a sua principal função consiste no armazenamento de energia em períodos de menor demanda e posterior utilização em momentos de maior demanda. Para tal, um sistema Load-Shift tem de ser capaz de converter os níveis de tensão da rede elétrica para os níveis de tensão do sistema de armazenamento e posteriormente permitir a conversão inversa, ou seja, adaptar os níveis de tensão do sistema armazenador para os níveis de tensão da rede elétrica. Neste sentido, a presente dissertação de mestrado foca-se no desenvolvimento de um conversor CC-CC bidirecional isolado, cuja principal função é gerir o carregamento e descarregamento das baterias eletroquímicas num sistema de Load-Shift. O trabalho desenvolvido está centrado num conversor CC-CC dual active bridge, onde foram abordadas e implementadas quatro técnicas de controlo distintas. Ao longo do desenvolvimento deste trabalho foi possível validar a topologia de conversor CC-CC bidirecional isolado, bem como as quatro técnicas phase shift abordadas para o sistema de controlo. Para estas técnicas de controlo foi estabelecida, através de resultados de simulação e resultados experimentais, uma comparação quanto às vantagens e desvantagens de cada uma delas, e performance de operação.Today, the use of electric energy is becoming more inevitable to perform the most common or important tasks. This situation leads to potential environmental problems and for that reason of renewable energy sources have been more and more used. However, some of these renewable energy sources, namely solar energy and wind energy, have the disadvantage of intermittent energy production throughout the day. Furthermore, in most cases, the periods of most energy production from renewable energy sources coincides with the periods of low demand of electrical energy, which aggravates the situation. Although of the existence of incentives to use electrical energy in periods of low demand, in most cases, this is not practicable. Thus, both to reinforce renewable energy use or to benefit from the incentives for using it in the periods of lower demand, emerge new opportunities related with storage and management systems for electrical energy. Although the Load-Shift systems can be associated for a variety of concepts, their main goal is the energy storage for a future use. Therefore, a Load-Shift system must be able to adapt the voltage level from the power grid to the voltage levels of the storage system, and allow the reverse operation, i.e., adapt the voltage levels from the storage system to the voltage levels of power grid. This Master thesis focuses on the development of a bidirectional isolated DC-DC converter, whose main function is to manage the charging and discharging of electrochemical batteries in a Load-Shift system. This work is centered in a DC-DC dual active bridge converter, in which were studied and implemented four different phase shift control techniques. During this work, it was possible to validate the topology of the isolated bidirectional DC-DC converter, as well as the four phase shift studied control techniques. For these four control techniques it was established a comparison in terms of advantages and disadvantages and operation performance, through simulation and experimental results