Electric Vehicle Power Supply Research Articles

Optimization of residential energy system configurations considering the bidirectional power supply of electric vehicles and electricity interchange between two residences

Electric vehicles (EVs) combined with bidirectional home chargers (vehicle-to-home (V2H) units) and electricity interchange between residences are promising options for the self-consumption of rooftop photovoltaics (PVs) in residences. Furthermore, considering that EVs have large storage capacities, one EV + V2H might support neighborhood-scale electricity storage by electricity interchange between residences, resulting in more cost-efficient self-consumption systems. Therefore, this paper investigates how permitting electricity interchange between residences affects the economically optimal design of distributed energy systems, such as PVs, EVs and V2H units. For this purpose, a mixed-integer linear programming model is developed to optimize the configurations and operation strategies of distributed energy resources (DERs) considering electricity interchange in neighborhoods. V2H units, which supply electricity from EVs to residences, are considered DER options independent of EVs. Furthermore, the optimization results are compared under two scenarios wherein electricity interchange is and is not permitted between two residences. The results indicate that permitting electricity interchange improves the self-consumption rate of PV power while reducing investment in storage facilities. The one influencing factor is sharing one EV + V2H between two residences and effectively utilizing the available storage capacity.

Design and simulation of 4 kW solar power-based hybrid EV charging station

Electric vehicles (EVs) have become an attractive alternative to IC engine cars due to the increased interest in lowering the consumption of fossil fuels and pollution. This paper presents the design and simulation of a 4 kW solar power-based hybrid EV charging station. With the increasing demand for electric vehicles and the strain they pose on the electrical grid, particularly at fast and superfast charging stations, the development of sustainable and efficient charging infrastructure is crucial. The proposed hybrid charging station integrates solar power and battery energy storage to provide uninterrupted power for EVs, reducing reliance on fossil fuels and minimizing grid overload. The system operates using a three-stage charging strategy, with the PV array, battery bank, and grid electricity ensuring continuous power supply for EVs. Additionally, the system can export surplus solar energy to the grid, reducing the load demand. The paper also discusses the use of MPPT techniques, PV cell modeling, and charge controller algorithms to optimize the performance of the hybrid charging station.

Emergency power supply enabling solar PV integration with battery storage and wireless interface

ABSTRACT This paper presents a detailed investigation of an emergency power supply that enables solar photovoltaic (PV) power integration with a battery energy storage system (BESS) and a wireless interface. Through the utilisation of solar PV-based generation and BESS with wireless/contactless power transmission, the proposed method offers an easy-to-setup and flexible alternative solution for the emergency power supply (EPS) for household appliances and wireless electric vehicle (EV) charging for all weather conditions. During bad weather conditions, the battery acts as the main power supply and can be charged from the solar PV panel and during rainy days, it can be charged from the grid by the proposed wireless interface for emergency use. The proposed system is analysed by mathematical modelling, focusing on the interface of the solar PV, BESS, and load, with inductive power transfer (IPT) as a wireless power transfer (WPT) method. The simulation and a scaled-down experimental prototype are built to demonstrate that the proposed system enables wireless power transfer with PV and BESS, and easy installation can be achieved by just placing the primary charging coil of the proposed power supply close to the wireless charging pad that is available in the existing system for e.g. EV charging. The results show that the load voltage is kept constant at 48 V against the varying input characteristic of the solar panel which is the solar irradiance ranging from 20% to 100% and output characteristics of the load of the proposed integrated system with variation of 20–50%, respectively. Moreover, the wireless power transfer efficiency across the inductive coils is maintained at about 97% under these variations.

A joint planning strategy for EV charging system towards net-zero transportation electrification

Electric vehicles (EVs) are pivotal in the progression toward sustainable transportation. However, a growing body of recent studies has challenged the often-assumed notion that electric vehicles are often considered to be net-zero emissions. These studies suggest that electric vehicles could potentially generate substantial emissions due to their reliance on fossil fuels to generate electricity, especially when receiving fast charging services. This phenomenon has been mitigated with the use of renewable energy sources in the power system. However, due to the intermittent nature of renewable energy sources, additional requirements have arisen. To address this situation, this paper presents an interdisciplinary study of collaborative fast-charging stations (FCS) and distributed renewable energy planning based on the interactions between traffic and power networks in order to increase the adoption rate of electric vehicles and reduce emissions caused by traffic and power systems. The locations and sizing of fast-charging stations, distributed photovoltaic generation, and renewable energy power supply for electric vehicles are determined in the proposed strategy through multi-objective integer programming. The proposed planning strategy considers heterogeneous electric vehicle driving range constraints, the operation security of the power distribution system, the reliability and expansion of the current power distribution, as well as different types of air pollutant classifications resulting from the charging behaviors. To guarantee the feasibility and accuracy of the planning results, an interactive algorithm is applied to solve the multi-objective integer model. Several cases are conducted to validate the proposed approach. The results demonstrate that the proposed planning strategy has good performance in the planning of fast-charging stations and distributed renewable energy integration.

Locational Analysis of In-motion Wireless Power Transfer System for Long-distance Trips by Electric Vehicles: Optimal Locations and Economic Rationality in Japanese Expressway Network

AbstractThe popularization of electric vehicles (EVs) is limited by their driving range and long charging times. To address this, in-motion wireless power transfer systems (WPTSs) are currently attracting attention as a new power supply system. In-motion WPTSs have coils embedded under the road to transfer power from the WPTSs to EVs while driving. However, the main drawback of WPTSs is their large investment, especially in supporting the long-distance trips of EVs on expressways. Therefore, this study proposes a new mixed-integer programming model (MIP) to determine the optimal location of WPTSs for maximized total feasible flow demand. By focusing on long-distance trips on expressways, we propose the first flow-capturing model for WPTS locations that can (i) solve for the distance of WPTS installed as continuous variables, and (ii) solve problems based on real-scale data using a general MIP solver. Our method is extended to a discussion of WPTS installations on expressways in Japan. We observe that WPTS has strong potential as an EV power supply system in terms of coverage and economic rationality. In particular, WPTS has economic rationality not only in busy networks but also in sparsely populated networks that connect urban and rural areas. Thus, this study clarifies the important insights of WPTSs in improving their effectivity to narrow down the demand and ensure the flexibility in the locations of WPTS.

Optimizing renewable polygeneration: A synergetic approach harnessing solar and wind energy systems

Transitioning from fossil fuels to renewable energy ensures a sustainable and green future by limiting greenhouse gas emissions and their nuisance effects. This study proposes a polygeneration system that harnesses renewable energy to produce multiple energy vectors simultaneously and equipped with storage to mitigate the impact of intermittent weather. To perform dynamic analysis, proposed system has been modeled, optimized, and simulated using the transient simulation software TRNSYS®. The designed model has been optimized in GenOpt, linked with TrnOpt, under the weather conditions of Gujrat, Pakistan. The power system is energized by solar photovoltaic, thermal and wind power to produce cooling, heating, electricity, hydrogen, and oxygen as energy vectors, and also provides electric, hydrogen, and thermal storage. Prime movers utilized for energy conversion consists of evacuated glass tube collector, photovoltaic panels, wind energy conversion system, fuel cell, electrolyzer, and absorption chiller, which facilitate air-conditioning, space and water heating, electric power supply for electric vehicle, building load & national grid, hydrogen for internal combustion engines, fuel cell electric vehicle and industrial applications, as well as oxygen for hospitals. The study has shown that thermal collector has 68% efficiency, a solar fraction 0.78, peak outlet temperature 143.77 °C, and generates a total 1399656.25 kJ thermal energy. The wind and photovoltaic systems have maximum efficiencies values 52.24 % and 10.90 % respectively, resulting in the production of 44.8 MWh electric energy. Embracing the synergy of solar and wind power in a polygeneration system holds the key to a sustainable and eco-friendly future.

Efficient power supply for electric vehicles: sodium-ion batteries

Energy is an important way to help daily work in various aspects of daily life. But energy cannot just exist around people without any carriers. Nowadays, sodium-ion batteries have been the best choice to be the carrier or power supply on account of the amount of sodium resources. On the other hand, it was anticipated that employing Na and Al current collectors for the cathode and anode would reduce costs. This paper mainly analyzes the current sodium ion battery structure, materials, and working principle, compared with other batteries' advantages and disadvantages and future development direction. The second part introduces sodium-ion batteries' anode and cathode materials, as well as the current mainstream materials, composition, and comparison between different mainstream materials. Sodium-ion battery is a relatively advanced battery in modern life, and its advantages are significantly greater than the lithium battery that is now used in life, especially in electric vehicles.

Enhancing the Electrochemical Properties of Nickel-Rich Cathode by Surface Coating with Defect-Rich Strontium Titanate.

Ni-rich layered ternary cathodes (i.e., LiNixCoyMzO2, M = Mn or Al, x + y + z = 1 and x ≥ 0.8) are promising candidates for the power supply of portable electronic devices and electric vehicles. However, the relatively high content of Ni4+ in the charged state shortens their lifespan due to inevitable capacity and voltage deteriorations during cycling. Therefore, the dilemma between high output energy and long cycle life needs to be addressed to facilitate more widespread commercialization of Ni-rich cathodes in modern lithium-ion batteries (LIBs). This work presents a facile surface modification approach with defect-rich strontium titanate (SrTiO3-x) coating on a typical Ni-rich cathode: LiNi0.8Co0.15Al0.05O2 (NCA). The defect-rich SrTiO3-x-modified NCA exhibits enhanced electrochemical performance compared to its pristine counterpart. In particular, the optimized sample delivers a high discharge capacity of ∼170 mA h/g after 200 cycles under 1C with capacity retention over 81.1%. The postmortem analysis provides new insight into the improved electrochemical properties which are ascribed to the SrTiO3-x coating layer. This layer appears to not only alleviate the internal resistance growth, from uncontrollable cathode-electrolyte interface evolution, but also acts as a lithium diffusion channel during prolonged cycling. Therefore, this work offers a feasible strategy to improve the electrochemical performance of layered cathodes with high nickel content for next-generation LIBs.

A Review on Interoperability of Wireless Charging Systems for Electric Vehicles

Wireless charging technology has become an important development trend in future electric vehicle (EV) power supply technology due to its safety, flexibility, and convenience. With its industrialized development, interoperability has become an essential technical link. The interoperability of wireless charging systems refers to the ability of output performance to meet specified indicators when different transmitter and receiver devices are matched. This study reviews the research status of the interoperability of EV wireless charging technology. First, the definition and composition of the interoperability of wireless charging systems are briefly given. Then, the article provides a review of standards about interoperability so far. The interoperability of various magnetic couplers and compensation topologies is also analyzed and summarized. After that, the paper reviews the existing interoperability evaluation methods. Finally, this work highlights the existing problems and challenges in current research of interoperability. We hope that this work will contribute to the further development of EV wireless charging technology.

The Suppression of Modular Multi-Level Converter Circulation Based on the PIR Virtual Impedance Strategy

In recent years, with the rise of the electric vehicle industry, there has been significant research on charging and power supply vehicle technologies for electric vehicles. In terms of the corresponding converter usage, modular multi-level converters (MMCs) are also increasingly used in the field of electric vehicle power supply research because of their unique advantages. However, the circulating current problem of MMCs has not been effectively addressed in existing domestic and international studies. In this paper, we propose a proportional-integral resonant (PIR) control method combined with virtual impedance for the optimal suppression of the MMC internal circulating current problem based on the comparison and generalization of the existing methods. Based on the analysis of the working principle of MMCs, this paper proposes and adopts the control strategy of combining virtual impedance and proportional-integral resonance to suppress the circulating current and builds a simulation model in MATLAB to verify that the control strategy proposed in this paper is feasible.

Reducing CO2 emissions in transportation systems: technologies for electric vehicles powering

This paper illustrates innovative transport systems for the power supply of electric vehicles as a replacement for the plug-in system. Different technologies for energy transfer are being developed worldwide: three of them are more mature, but other may come. Nowadays, the mainly three systems under development are the following: overhead cable power supply system, ground contact power supply system and the contactless wireless charging methodology using the Dynamic Wireless Power Transfer system.In particular, the last-mentioned methodology will be described in detail, the materials research experience involved the 'Laboratory of Applied Research for Innovation and Technology Transfer' at the University of Parma.Among the main differences are that recharging technology by aerial contact and the scientific application of ground contact for vehicle recharging has been developed and applied particularly to heavy vehicles such as trucks and buses. On the other hand, the wireless recharging system is tested and applied not only for heavy transport vehicles but also for small transport vehicles such as cars.

Optimization of Charging/Battery-Swap Station Location of Electric Vehicles with an Improved Genetic Algorithm-Based Model

The joint location planning of charging/battery-swap facilities for electric vehicles is a complex problem. Considering the differences between these two modes of power replenishment, we constructed a joint location-planning model to minimize construction and operation costs, user costs, and user satisfaction-related penalty costs. We designed an improved genetic algorithm that changes the crossover rate using the fitness value, memorizes, and transfers excellent genes. In addition, the present model addresses the problem of “premature convergence” in conventional genetic algorithms. A simulated example revealed that our proposed model could provide a basis for optimized location planning of charging/battery-swapping facilities at different levels under different charging modes with an improved computing efficiency. The example also proved that meeting more demand for power supply of electric vehicles does not necessarily mean increasing the sites of charging/battery-swap stations. Instead, optimizing the level and location planning of charging/battery-swap stations can maximize the investment profit. The proposed model can provide a reference for the government and enterprises to better plan the location of charging/battery-swap facilities. Hence, it is of both theoretical and practical value.

DPC of Cross-compensated Virtual Flux Double Switch Table

Aiming at the problems of large power ripple, high harmonic components and DC bias on the AC side of the three-phase voltage rectifier Direct Power Control (DPC), as well as the shortcomings of the voltage output of the DC side busbar, the direct power control method of the cross-compensated virtual flux double switch meter has been proposed. The virtual flux can realize the sensorless mode on the input side of the circuit to reduce the high harmonic, even if the first-order low-pass filter is used to replace the integration region, there is still some error. On this basis, the two filters are connected in parallel for virtual flux compensation, and then the voltage vector is selected according to the instantaneous power change, and the sector is re-divided with the voltage as the control vector, and two independent switching state tables are designed. The cross-compensated virtual flux double-switch meter DPC is simulated and compared with the traditional DPC waveform, and the experimental results show that the cross-compensated virtual flux double-switch meter DPC strategy can effectively reduce the proportion of harmonic content, control power fluctuations, improve DC bias, has fast tracking effect, stabilize output voltage, and control active and reactive power flexibly. The three-phase voltage rectifier circuit occupies an important position for the pre-rectifier part of the charging power supply of electric vehicles, and the rectifier circuit that can stabilize the output DC voltage cannot only extend its service life for the charging power supply, but also reduce harmonic pollution.

Analysis and Research on Power Supply Strategies of Electric Vehicles Based on Wind Farms

The widespread growth of electric vehicles could pose significant grid and charging infrastructure challenges, especially in areas with underdeveloped infrastructure. This has affected the ease of charging electric vehicles. In this paper, I design a power supply strategy for electric vehicle charging facilities based on wind farm power supply. In this strategy, a preliminary selection of line conductors is carried out, and several schemes are preliminarily determined. Further comparative analysis is made from the three aspects of conductor, tower type, and bus. Through the PowerWorld software, a simulation model is established for each scheme, and an optimal strategy that takes into account economy, security, and system stability is obtained (AAC 31.5 mm double split, tower A and bus 5). This can assist in the transformation of electric vehicle power supply and the construction of wind farm power supply facilities.

COMPARATIVE ANALYSIS OF TECHNICAL CHARACTERISTICS OF CHARGING STATIONS OF ELECTRIC VEHICLES

The article analyzes and compares charging stations for electric vehicles and their components. The analysis of charging modes of electric vehicles showed that four internationally standardized modes are used, three of which use alternating current with single-phase and three-phase switching and only one – direct current. When charging on direct current, the fastest charging is provided. There are four standardized cases of connecting charging stations to electric vehicles. Three cases of cable connection can be used on alternating current, only the third case – on direct current, and the fourth case – when wirelessly charging an electric car. Analysis of the principles of use of charging stations showed that they classify portable, wall, and stationary stations. National standards introduce road signs for electric vehicles, and a European standard establishes harmonized identifiers for the power supply of electric vehicles. There are some standardized protocols for the interaction of the charging station and the control server, which are designed to optimize energy resources and energy production systems. A comparison of existing types of connectors for charging electric vehicles has shown that the standardized interface between the charging station and the electric vehicle remains one of the most acute problems. Recommendations on approaches to metrological support of charging stations are formulated. The issue of international and regional standardization of electricity meters of direct current for use in charging stations remains relevant. International standards are transformed into relevant European standards without changes. However, in some cases, it is necessary to develop a special European standard, in particular for meters of active electrical energy of the direct current.

Technical and economic calculation of a solar-powered charging station for electric vehicles

Problem. Development and implementation of green technologies is both an urgent and a cost-effective scientific and engineering task. Therefore, the issues related to the study of renewable energy sources, which are used as the main sources of energy for electric vehicles, are quite relevant and promising. At the same time, an equally important question is how profitable is building solar charging stations in terms of both ecology and economy. Goal. The aim is calculation and analysis of technical and economic indicators of a solar charging station for electric vehicles (EV). Methodology. The analytical methods of studying the development and application of the ways and devices to transform the energy of the sun into electricity are used, as well as the methods of experimental research and mathematical methods of processing and modulation of the received results; methods of calculating technical and economic indicators. Results. The review of the literature on the development of renewable energy sources, in particular, solar power plants, and the spread of electric vehicles with the gradual displacement (replacement) of traditional cars working on internal combustion engines with electric vehicles (BEV and PHEV) was made. The main parameters and technical characteristics of the solar-powered charging station (SPCS) were studied. For the analysis and calculation of technical and economic indicators of SPCS for EV it is offered to take a SPP with a capacity of 20 kW as a basis. The calculation of SPCS electricity generation both for own consumption and for power supply of EV and the sale of surplus electricity to the general network at the “green tariff” was carried out. Originality. The technical and economic calculation of SCS was made taking into account the rise of electricity prices in Kharkiv region (Ukraine). Practical value. According to the analysis of the obtained results, it can be said that the payback period of SPCS for EV is about 7.9 years. If we consider the constant increase in the cost of electricity (approximately 15% per year), we can expect the payback after 6.8 years of operation.

Research on Desktop Wide Range Wireless Power Transfer Based on High Frequency Electric Field

This paper proposes a desktop wireless power transfer system that can wirelessly supply power to electrical equipment in a certain space above the aluminum foil using only a high-frequency electric field. Compared with other wireless power supply systems, this system has a smaller power receiving device and a wider power supply range, which is convenient for wireless power supply of portable electrical equipment and low-power electric vehicles. The power receiving device of the system is only the size of a mobile phone, and the power supply range can reach 1.2 m2. This article introduces the system design, electromagnetic field simulation and experiment of the desktop wireless power transfer system. The experimental results show that by using a mobile phone-sized receiving device to connect a light bulb and a fan, multiple loads can simultaneously receive power in a specific space above the desktop power supply. In addition, people can hold the power receiving device for wireless charging.

Efficient Blockchain-Enabled Large Scale Parked Vehicular Computing With Green Energy Supply

While the vehicular network enables geographically distributed cooperative computation, its mature implementation has long been constrained due to the lack of an effective management platform. In this paper, employing the security and privacy attributes of blockchain, we propose a novel Blockchain-enabled Large-scale Parked Vehicular Computing (BLPVC) architecture to utilize the potential solar energy and vehicular computational resources in the outdoor parking lot. However, the uneven green power supply and random arrival time of electric vehicles compose the highly complex environment. Accordingly, in this paper, to handle the efficient utilization of the distributed resources by blockchain technology, we propose an integrated optimization framework which leverages the green energy utilization and service latency limit among the processes of block generation, task computing, and communication, whereas such a design leads to the mixed-timescale stochastic optimization problem. To this end, corresponding to the dynamic solar energy arrival, we propose a shaped deep deterministic policy gradient (DDPG) algorithm to accelerate the learning rate of computational frequency control in the short-term stage; while in the long-term stage, for the mixed-integer programming (MIP) of task offloading and blockchain parameters adjustment, a series of transformation is employed to preserve convexity. Finally, experiments are carried out on Python demonstrating that the proposed scheme achieves a balanced performance between service latency and distributed resources, while the battery depreciation cost is heavily reduced.

Design of monitoring system for electric vehicle charging station based on LabVIEW and STM32

Charging-station provides power supply for electric vehicles, which is a necessary and important energy supporting infrastructure for development and large scale commercialization operation of electric.For the current charging-station management is overly dependent on high-cost devices such as industrial computer, this paper develops a charger field test device, which adopts STM32 as the data exchange interface between the host computer and charger. The charge data is sent to PC through STM32, and the monitoring system development is designed by LABVIEW.This method optimizes the decoding of message content, overcomes the defect of over reliance on high cost components, and strengthenes the ability of bottom message collection, enhances the system intelligence.The communication is fast, reliable and has a good man-machine interface.

Multy-modality Switch Modeling and Simulation of A Three-port DC-DC Converter

A three-port DC-DC converter (TPC) for photo-voltaic (PV) electric vehicle (EV) was presented in this paper. A PV module and a battery consist of the power supply for electric vehicle. A boost converter helps the PV module to output maximum power. A sepic-zeta converter helps the battery to be charged by PV power or output power for EV. A cuk converter was used to keep the stability of output voltage for load. There are five modalities for the TPC model and three applications were simulated to verify the performance of different modality switching. The simulation results show that the given TPC model have some advantages, such as small steady errors, short transient times and small fluctuation of voltage and power. This TPC can be used in EV to provide a steady voltage for motor and extend the driving distance.