Review of Electric Vehicle Charging Technologies, Configurations, and Architectures

Electric Vehicles (EVs) are projected to be one of the major contributors to energy transition in the global transportation due to their rapid expansion. The EVs will play a vital role in achieving a sustainable transportation system by reducing fossil fuel dependency and greenhouse gas (GHG) emissions. However, high level of EVs integration into the distribution grid has introduced many challenges for the power grid operation, safety, and network planning due to the increase in load demand, power quality impacts and power losses. An increasing fleet of electric mobility requires the advanced charging systems to enhance charging efficiency and utility grid support. Innovative EV charging technologies are obtaining much attention in recent research studies aimed at strengthening EV adoption while providing ancillary services. Therefore, analysis of the status of EV charging technologies is significant to accelerate EV adoption with advanced control strategies to discover a remedial solution for negative grid impacts, enhance desired charging efficiency and grid support. This paper presents a comprehensive review of the current deployment of EV charging systems, international standards, charging configurations, EV battery technologies, architecture of EV charging stations, and emerging technical challenges. The charging systems require a dedicated converter topology, a control strategy and international standards for charging and grid interconnection to ensure optimum operation and enhance grid support. An overview of different charging systems in terms of onboard and off-board chargers, AC-DC and DC-DC converter topologies, and AC and DC-based charging station architectures are evaluated

System configuration, fault detection, location, isolation and restoration: a review on LVDC Microgrid protections

Low voltage direct current (LVDC) distribution has gained the significant interest of research due to the advancements in power conversion technologies. However, the use of converters has given rise to several technical issues regarding their protections and controls of such devices under faulty conditions. Post-fault behaviour of converter-fed LVDC system involves both active converter control and passive circuit transient of similar time scale, which makes the protection for LVDC distribution significantly different and more challenging than low voltage AC. These protection and operational issues have handicapped the practical applications of DC distribution. This paper presents state-of-the-art protection schemes developed for DC Microgrids. With a close look at practical limitations such as the dependency on modelling accuracy, requirement on communications and so forth, a comprehensive evaluation is carried out on those system approaches in terms of system configurations， fault detection, location, isolation and restoration

A review of the emergency electric power supply systems at PWR nuclear power plants

Bibliography: pages 168-174.The Emergency Electric Power Supply Systems at Pressurized Water Reactor Nuclear Power Plants are reviewed, problem areas are identified, and recommendations are made for existing and future Nuclear Power Plants. A simplified introduction to a typical Pressurized Water Nuclear Reactor is given and the problems associated with the commercial use of nuclear power are discussed. An overview of the Nuclear industry's solutions is presented and covers the Reliability of equipment and the American Regulatory requirements. The alternating and direct current power supply systems are examined in terms of plant operational state and equipment type (Diesel generators, Grid network, Lead-acid batteries, Battery chargers, Inverters, and Power Distribution networks). The trends in the design of Emergency Electric Power supply systems at Nuclear Power Plants are presented. The loss of all alternating current power, known as Station Blackout, is discussed and the American and European response to this. problem is presented. Problems experienced in the direct current systems are discussed and solutions are presented. The experience at Koeberg Nuclear Power station with Lead-acid batteries is included in the discussion. The thesis concludes with recommendations for designers and operators of the Electric Power Supply Systems at Nuclear Power Stations

Operation modes for the electric vehicle in smart grids and smart homes: present and proposed modes

This paper presents the main operation modes for an electric vehicle (EV) battery charger framed in smart grids and smart homes, i.e., are discussed the present-day and are proposed new operation modes that can represent an asset towards EV adoption. Besides the well-known grid to vehicle (G2V) and vehicle to grid (V2G), this paper proposes two new operation modes: Home-to-vehicle (H2V), where the EV battery charger current is controlled according to the current consumption of the electrical appliances of the home (this operation mode is combined with the G2V and V2G); Vehicle-for-grid (V4G), where the EV battery charger is used for compensating current harmonics or reactive power, simultaneously with the G2V and V2G operation modes. The vehicle-to-home (V2H) operation mode, where the EV can operate as a power source in isolated systems or as an off-line uninterruptible power supply to feed priority appliances of the home during power outages of the electrical grid is presented in this paper framed with the other operation modes. These five operation modes were validated through experimental results using a developed 3.6 kW bidirectional EV battery charger prototype, which was specially designed for these operation modes. The paper describes the developed EV battery charger prototype, detailing the power theory and the voltage and current control strategies used in the control system. The paper presents experimental results for the various operation modes, both in steady-state and during transients

Electric vehicle smart charging

In recent years, the number of electric vehicles (EVs) has been increasing. It will play more and more important role in the power grid operation because of its storage features, where charging and discharging control strategies and construction of the charging facilities are the priorities to be solved in this field. At the same time, the availability of the charging infrastructures is still limited and provides a promising application area for communication and control research. This thesis focuses on the control of the energy status offered by the buildings/houses providing a power management across the EV charging session. It also describes the development of a system to dynamically control the charging of EVs and maintain the operation of the power system by knowing the available power. To charge EVs a communication between the EV and the charging station is needed. The communication is based on the standard IEC61851, which specifies a pulse width modulation (PWM) signal that is sent to the EV to define the charging current. The system hardware consists of two modules, a charging station and a coordinator both with communication capabilities, while the power management algorithms are in a server, which then calculates the available power based on the power consumption behaviour and uses it to assign the charge of the EV. The system aims to control the EV charging session considering the power consumption to control their charging current. For the case of multiple EVs, the system will manage the charging session based on a priority level prioritizing the EV how started to charge first. The results shows the feasibility of the charging system approach to control the EV charging station considering the system power consumption and the introduction of the priority level for multiple EVs.Nos últimos anos, o número de veículos elétricos está aumentando. Eles desempenham um papel cada vez mais importante na operação da rede elétrica por causa do seu recurso de armazenamento, onde as estratégias do controlo de carregamento e descarregamento e a construção das instalações de carregamento são as prioridades a serem resolvidas neste campo. Ao mesmo tempo, a disponibilidade das infraestruturas de carregamento ainda é limitada e fornece uma área de aplicação promissora para pesquisa em comunicação e controlo. Esta tese concentra-se no controlo do estado de energia oferecido pelos edifícios/casas fornecendo uma gestão de energia durante a sessão de carregamento de veículo elétrico. Também descreve o desenvolvimento de um sistema para controlar dinamicamente o carregamento dos veículos elétricos para manter a operação do sistema de energia, conhecendo a energia disponível. Para carregar os veículos elétricos, é necessária uma comunicação entre o veículo elétrico e a estação de carregamento. A comunicação é baseada na norma IEC61851, que especifica um sinal de modulação por largura de pulso enviado ao veículo elétrico para definir a corrente de carregamento. O hardware do sistema consiste em dois módulos, uma estação de carregamento e um coordenador ambos com capacidade de comunicação, enquanto os algoritmos de gestão de energia estão num servidor que calcula a energia disponível com base no comportamento do consumo de energia e usa-o para atribuir a carga do veículo elétrico. O sistema tem como objetivo controlar a sessão de carregamento do veículo elétrico, considerando o consumo de energia para controlar a corrente de carregamento. No caso de vários veículos elétricos, o sistema irá gerir a sessão de carregamento com base em um nível de prioridade, priorizando o veículo elétrico que iniciou o primeiro carregamento. Os resultados mostram a viabilidade da abordagem do sistema de carregamento para controlar a estação de carregamento do veículo elétrico, considerando o consumo de energia do sistema e a introdução do nível de prioridade para vários veículos elétricos

Power Management and Protection in MT-HVDC Systems with the Integration of High-Voltage Charging Stations

Due to the significant increase of the long-distance electricity demand, effective use of Distributed Generations (DGs) in power system, and the challenges in the expansion of new transmission lines to improve the reliability of power system reliability, utilizing Multi-Terminal HVDC (MT-HVDC) technology is an applicable, reliable, and cost-effective solution in hybrid AC/DC grids. MT-HVDC systems have flexibility in terms of independent active and reactive power flow (reversible control) and voltage control. Interconnecting two AC grids with different frequencies and transmitting electricity for the long-distance with low power-losses, which leads to less operation and maintenance costs, can be done through the MT-HVDC systems. The integration of large-scale remote DGs, e.g., wind farms, solar power plants, etc., and high-voltage charging stations for Electric Vehicles (EVs) into the power grid have different issues, such as economic, technical, and environmental challenges of transmission and network expansion/operation of both AC and DC grids. In details, damping oscillation, voltage support at different buses, operation of grid-connected inverters to the off-shore and on-shore AC systems, integrating of existing converter stations in MT-HVDC systems without major changes in control system, evaluation of communication infrastructure and also reactive power and filtering units’ requirements in MT-HVDC systems are the technical challenges in this technology. Therefore, a reliable MT-HVDC system can be a possible mean of resolving all the above-mentioned issues. MT-HVDC systems need a control system that can bring stability to the power system during a certain period of the operation/planning time while providing effective and robust electricity. This thesis presents an improved droop-based control strategy for the active and reactive power-sharing on the large-scale MT-HVDC systems integrating different types of AC grids considering the operation of the hybrid AC/DC grids under normal/contingency conditions. The main objective of the proposed strategy is to select the best parameters of the local terminal controllers at the site of each converter station (as the primary controller) and a central master controller (supervisory controller) to control the Power Flow (PF) and balance the instantaneous power in MT-HVDC systems. In this work, (1) various control strategies of MT-HVDC systems are investigated to propose (2) an improved droop-based power-sharing strategy of MT-HVDC systems while the loads (e.g., high-voltage charging stations) in power systems have significant changes, to improve the frequency response and accuracy of the PF control, (3) a new topology of a fast proactive Hybrid DC Circuit Breaker (HDCCB) to isolate the DC faults in MT-HVDC grids in case of fault current interruption. The results from this research work would include supporting energy adequacy, increasing renewable energy penetration, and minimizing losses when maintaining system integrity and reliability. The proposed strategies are evaluated on different systems, and various case scenarios are applied to demonstrate their feasibility and robustness. The validation processes are performed using MATLAB software for programming, and PSCAD/EMTDC and MATLAB/Simulink for simulation

National Conference on ‘Renewable Energy, Smart Grid and Telecommunication-2023

Theme of the Conference: “The challenges and opportunities of integrating renewable energy into the grid” The National Conference on Renewable Energy, Smart Grid, and Telecommunication - 2023 is a platform for industry experts, researchers, and policymakers to come together and explore the latest advancements and challenges in the fields of renewable energy, smart grids, and telecommunication. Conference Highlights: In-depth discussions on renewable energy technologies and innovations. Smart grid integration for a sustainable future. The role of telecommunication in advancing renewable energy solutions. Networking opportunities with industry leaders and experts. Presentation of cutting-edge research papers and case studies. Conference topics: Renewable Energy Technologies and Innovations Smart Grid Development and Implementation Telecommunication for Energy Systems Energy Storage and Grid Balancing Policy, Regulation, and Market Dynamics Environmental and Social Impacts of Renewable Energy Energy Transition and Future Outlook Integration of renewable energy into the grid Microgrids and decentralized energy systems Grid cybersecurity and data analytics IoT and sensor technologies for energy monitoring Data management and analytics in energy sector Battery storage technologies and applicationshttps://www.interscience.in/conf_proc_volumes/1087/thumbnail.jp