Electric Vehicles Charging Stations’ Architectures, Criteria, Power Converters, and Control Strategies in Microgrids

Electric Vehicles (EV) usage is increasing over the last few years due to a rise in fossil fuel prices and the rate of increasing carbon dioxide (CO2) emissions. The EV charging stations are powered by the existing utility power grid systems, increasing the stress on the utility grid and the load demand at the distribution side. The DC grid-based EV charging is more efficient than the AC distribution because of its higher reliability, power conversion efficiency, simple interfacing with renewable energy sources (RESs), and integration of energy storage units (ESU). The RES-generated power storage in local ESU is an alternative solution for managing the utility grid demand. In addition, to maintain the EV charging demand at the microgrid levels, energy management and control strategies must carefully power the EV battery charging unit. Also, charging stations require dedicated converter topologies, control strategies and need to follow the levels and standards. Based on the EV, ESU, and RES accessibility, the different types of microgrids architecture and control strategies are used to ensure the optimum operation at the EV charging point. Based on the above said merits, this review paper presents the different RES-connected architecture and control strategies used in EV charging stations. This study highlights the importance of different charging station architectures with the current power converter topologies proposed in the literature. In addition, the comparison of the microgrid-based charging station architecture with its energy management, control strategies, and charging converter controls are also presented. The different levels and types of the charging station used for EV charging, in addition to controls and connectors used in the charging station, are discussed. The experiment-based energy management strategy is developed for controlling the power flow among the available sources and charging terminals for the effective utilization of generated renewable power. The main motive of the EMS and its control is to maximize usage of RES consumption. This review also provides the challenges and opportunities for EV charging, considering selecting charging stations in the conclusion.publishedVersio

The presentation of sustainable power source assets in the field of intensity age assumes an imperative job

DC to DC converters to interface lesser-voltage higher-control supply to the essential stock shows the most raised proficiency was practiced in the full-connect converter. Non-separated converters bury unified inductor help converters with essential voltage gain and furthermore converters hold lesser profitability, yet they huge in structure, even the quantity of latent parts is diminished. In like manner gives proficient utilization of semiconductor switches, have higher voltage yield and are prepared to work in lesser estimation of D interestingly with every single disconnected converter. High addition topologies are regularly outfitted with high voltage security structures. Few non-disengaged topologies gives voltage hang security circuits are pointless since capacitive fragments and circuit plan are progressed to work under higher information voltage and low power. That requires lesser qualities for convincing RAC obstruction and entomb partnered inductance dispersal to achieve more prominent adequacy of intensity change. Larger supply current needs extensive region of core area inter allied inductors

Control of distributed power in microgrids: PV field to the grid, islanding operation, and ultra-fast charging station.

Aquesta tesi explora el control de l'energia distribuïda en microxarxes (MG) i aborda diversos reptes relacionats amb el control, l'estabilitat, la compartició d'energia, el disseny del convertidor d'energia, la connexió a la xarxa, la càrrega ultraràpida i el subministrament d'energia renovable. El rendiment dels MG s'analitza tant en modes d'operació connectats a la xarxa com en illa, considerant diferents configuracions i escenaris de flux d'energia. La tesi se centra en diversos reptes clau, com ara maximitzar l'extracció d'energia de matrius fotovoltaiques (PV) en MG que utilitzen convertidors DC-DC, injectar potència MG excedent a la xarxa principal mitjançant inversors de font de tensió DC-AC (VSI) sota càrregues no lineals i desequilibrades, optimitzant el rendiment de MG i la compartició d'energia en mode illa mitjançant VSI, connectant-se a la xarxa principal en el punt d'acoblament comú (PCC) mitjançant transformadors de baixa freqüència (LFT) i transformadors d'estat sòlid (SST) i explorant topologies de convertidors de potència per ultra -càrrega ràpida de CC de vehicles elèctrics (EV). L'ús de SST en lloc de LFT pot millorar la capacitat de MG alhora que redueix el volum i el pes de l'arquitectura elèctrica MG. Aquesta tesi proporciona coneixements i solucions per abordar els reptes esmentats anteriorment, contribuint a l'avenç del control, l'estabilitat, la qualitat de l'energia i la integració eficient de les fonts d'energia renovables i la càrrega dels vehicles elèctrics.Esta tesis explora el control de la potencia distribuida en microrredes (MGs) y aborda diversos retos relacionados con el control, la estabilidad, el reparto de potencia, el diseño de convertidores de potencia, la conexión a la red, la carga ultrarrápida y el suministro de energías renovables. El rendimiento de las MG se analiza tanto en modo de funcionamiento conectado a la red como en modo aislado, considerando diferentes configuraciones y escenarios de flujo de potencia. La tesis se centra en varios retos clave, como la maximización de la extracción de energía de las matrices fotovoltaicas (FV) en las MG utilizando convertidores CC-CC, la inyección del excedente de energía de las MG en la red principal a través de inversores de fuente de tensión CC-CA (VSI) bajo cargas no lineales y desequilibradas, la optimización del rendimiento de las MG y del reparto de energía en modo aislado mediante VSI, la conexión a la red principal en el punto de acoplamiento común (PCC) mediante transformadores de baja frecuencia (LFT) y transformadores de estado sólido (SST), y la exploración de topologías de convertidores de potencia para la carga ultrarrápida en corriente continua de vehículos eléctricos (VE). El uso de SST en lugar de LFT puede mejorar la capacidad de la MG y, al mismo tiempo, reducir el volumen y el peso de la arquitectura eléctrica de la MG. Esta tesis aporta ideas y soluciones para abordar los retos mencionados, contribuyendo al avance del control de la MG, la estabilidad, la calidad de la energía y la integración eficiente de fuentes de energía renovables y la carga de vehículos eléctricos. Traducción realizada con la versión gratuita del traductor www.DeepL.com/TranslatorThis thesis explores the control of distributed power in microgrids (MGs) and addresses various challenges related to control, stability, power sharing, power converter design, grid connection, ultra-fast charging, and renewable energy supply. The performance of MGs is analysed in both grid-connected and islanded modes of operation, considering different configurations and power flow scenarios. The thesis focuses on several key challenges, including maximising power extraction from photovoltaic (PV) arrays in MGs utilizing DC-DC converters, injecting surplus MG power into the main grid via DC-AC voltage source inverters (VSIs) under nonlinear and unbalanced loads, optimising MG performance and power sharing in islanded mode through VSIs, connecting to the main grid at the point of common coupling (PCC) using low-frequency transformers (LFTs) and solid-state transformers (SSTs), and exploring power converter topologies for ultra-fast DC charging of electric vehicles (EVs). The use of SSTs instead of LFTs can enhance MG capability while reducing the volume and weight of the MG electrical architecture. This thesis provides insights and solutions to address the aforementioned challenges, contributing to the advancement of MG control, stability, power quality, and efficient integration of renewable energy sources and EV charging

Three-Port Bi-Directional DC–DC Converter with Solar PV System Fed BLDC Motor Drive Using FPGA

The increased need for renewable energy systems to generate power, store energy, and connect energy storage devices with applications has become a major challenge. Energy storage using batteries is most appropriate for energy sources like solar, wind, etc. A non-isolated three-port DC–DC-converter energy conversion unit is implemented feeding the brushless DCmotor drive. In this paper, a non-isolated three-port converter is designed and simulated for battery energy storage, interfaced with an output drive. Based on the requirements, the power extracted from the solar panel during the daytime is used to charge the batteries through the three-port converter. The proposed three-port converter is analyzed in terms of operating principles and power flow. An FPGA-based NI LabView PXI with SbRio interface is used to develop the suggested approach’s control hardware, and prototype model results are obtained to test the proposed three-port converter control system’s effectiveness and practicality. The overall efficiency of the converter’s output improves as a result. The success rate is 96.5 percent while charging an ESS, 98.1 percent when discharging an ESS, and 95.7 percent overall

Special Power Electronics Converters and Machine Drives with Wide Band-Gap Devices

Power electronic converters play a key role in power generation, storage, and consumption. The major portion of power losses in the converters is dissipated in the semiconductor switching devices. In recent years, new power semiconductors based on wide band-gap (WBG) devices have been increasingly developed and employed in terms of promising merits including the lower on-state resistance, lower turn-on/off energy, higher capable switching frequency, higher temperature tolerance than conventional Si devices. However, WBG devices also brought new challenges including lower fault tolerance, higher system cost, gate driver challenges, and high dv/dt and resulting increased bearing current in electric machines. This work first proposed a hybrid Si IGBTs + SiC MOSFETs five-level transistor clamped H-bridge (TCHB) inverter which required significantly fewer number of semiconductor switches and fewer isolated DC sources than the conventional cascaded H-bridge inverter. As a result, system cost was largely reduced considering the high price of WBG devices in the present market. The semiconductor switches operated at carrier frequency were configured as Silicon Carbide (SiC) devices to improve the inverter efficiency, while the switches operated at fundamental output frequency (i.e., grid frequency) were constituted by Silicon (Si) IGBT devices. Different modulation strategies and control methods were developed and compared. In other words, this proposed SiC+Si hybrid TCHB inverter provided a solution to ride through a load short-circuit fault. Another special power electronic, multiport converter, was designed for EV charging station integrated with PV power generation and battery energy storage system. The control scheme for different charging modes was carefully developed to improve stabilization including power gap balancing, peak shaving, and valley filling, and voltage sag compensation. As a result, the influence on the power grid was reduced due to the matching between daily charging demand and adequate daytime PV generation. For special machine drives, such as slotless and coreless machines with low inductance, low core losses, typical drive implementations using conventional silicon-based devices are performance limited and also produce large current and torque ripples. In this research, WBG devices were employed to increase inverter switching frequency, reduce current ripple, reduce filter size, and as a result reduce drive system cost. Two inverter drive configurations were proposed and implemented with WBG devices in order to mitigate such issues for 2-phase very low inductance machines. Two inverter topologies, i.e., a dual H-bridge inverter with maximum redundancy and survivability and a 3-leg inverter for reduced cost, were considered. Simulation and experimental results validated the drive configurations in this dissertation. An integrated AC/AC converter was developed for 2-phase motor drives. Additionally, the proposed integrated AC/AC converter was systematically compared with commonly used topologies including AC/DC/AC converter and matrix converters, in terms of the output voltage/current capability, total harmonics distortion (THD), and system cost. Furthermore, closed-loop speed controllers were developed for the three topologies, and the maximum operating range and output phase currents were investigated. The proposed integrated AC/AC converter with a single-phase input and a 2-phase output reduced the switch count to six and resulting in minimized system cost and size for low power applications. In contrast, AC/DC/AC pulse width modulation (PWM) converters contained twelve active power semiconductor switches and a common DC link. Furthermore, a modulation scheme and filters for the proposed converter were developed and modeled in detail. For the significantly increased bearing current caused by the transition from Si devices to WBG devices, advanced modeling and analysis approach was proposed by using coupled field-circuit electromagnetic finite element analysis (FEA) to model bearing voltage and current in electric machines, which took into account the influence of distributed winding conductors and frequency-dependent winding RL parameters. Possible bearing current issues in axial-flux machines, and possibilities of computation time reduction, were also discussed. Two experimental validation approaches were proposed: the time-domain analysis approach to accurately capture the time transient, the stationary testing approach to measure bearing capacitance without complex control development or loading condition limitations. In addition, two types of motors were employed for experimental validation: an inside-out N-type PMSM was used for rotating testing and stationary testing, and an N-type BLDC was used for stationary testing. Possible solutions for the increased CMV and bearing currents caused by the implementation of WGB devices were discussed and developed in simulation validation, including multi-carrier SPWM modulation and H-8 converter topology

A Novel High Gain Dual Input Single Output Z-Quasi Resonant (ZQR) DC/DC Converter for Off-Board EV Charging

This manuscript focuses on a Multi-port non-isolated (Dual input and single output) DC/DC power electronic interface based on Z-Quasi resonant (ZQR) network. The converter accommodates grid and Photovoltaic panel (PV) as its input sources. Unlike the basic DC/DC converters, the recommended DC/DC converter requires fewer switches and provides continuous current, high voltage gain, and minimal voltage stress on converter switch up to 40% duty cycle owing to the presence of ZQR network. This feature of the converter makes it suitable for applications like Electric Vehicle (EV) off-board charging, where a high voltage gain is required. The purpose of this paper is to develop and evaluate a multi-port ZQR DC/DC converter for EVs. In the proposed multi-port ZQR converter, additional input and output ports could be appended without compromising the converter's gain and efficiency. The developed converter can operate continuously even if any one of the input sources fails to charge the EV. The proposed converter is mathematically modeled using basic laws that govern the converter performance and analyzed in MATLAB Simulink platform under various operating modes. A detailed analysis under steady-state and dynamic conditions as well as a comparison of the developed multiport ZQR DC/DC converter with the topologies addressed in published literature are also presented in this manuscript. In order to verify the proposed converter performance, a prototype model of 300 W has been designed and developed with a switching frequency of 20 kHz. Experimental results confirm the effectiveness of the theoretical analysis, the aforementioned advantages, and features of the proposed multiport ZQR DC/DC converter.publishedVersio

Power Converters in Power Electronics

In recent years, power converters have played an important role in power electronics technology for different applications, such as renewable energy systems, electric vehicles, pulsed power generation, and biomedical sciences. Power converters, in the realm of power electronics, are becoming essential for generating electrical power energy in various ways. This Special Issue focuses on the development of novel power converter topologies in power electronics. The topics of interest include, but are not limited to: Z-source converters; multilevel power converter topologies; switched-capacitor-based power converters; power converters for battery management systems; power converters in wireless power transfer techniques; the reliability of power conversion systems; and modulation techniques for advanced power converters