Frequency bifurcation study of an inductive power transmission system

In order to reduce the system cost, volumetric size and weight of an electric vehicles (EVs) battery charger, a novel four-switch two-leg VSI configuration is propose for rapid battery charging with the active power filter (APF) features. It consists of cost-effective two-arm bridge converter, coupling inductors, LC filters, buck converter and EV battery. Note that the conventional three-leg bridge structure is reduce to two-leg VSI structure, functioning like three-phase rectifier to converts power from ac-dc during the battery charging process. The third-leg and set of power switching devices are eliminate by directly connecting the grid phase with the negative terminals of dc-link capacitor. Therefore, third leg of the EV charger is use as a buck converter for battery charging. The charger controller ensures the rapid charging capabilities in constant current and constant voltage (CC-CV) modes, with additional functions of harmonic compensation capability, power factor correction, reactive power compensation and constant dc-link voltage. The experimental results verify the validity and effectiveness performance of the laboratory based EV charger prototype.

Repurposed electric vehicle battery performance in second-life electricity grid frequency regulation service

Electromobility is associated with the ever faster development and introduction of new electric vehicles to the market. These vehicles use an electric motor to drive the wheels of the vehicle and the necessary electrical energy is stored in traction batteries. Electric vehicles have a different construction method than traditional vehicles powered by internal combustion engines. For this reason, they are used, maintained and serviced differently. Becoming more familiar with selected operational issues of electric vehicles positively affects the reliability of their use as well as the safety and comfort of driving them. One important component of electric vehicles is the traction battery. Its proper operation influences the long-term preservation of the initial energy capacity and thus the range of the vehicle. The article presents test results concerning the state of traction batteries of a small electrically powered city vehicle. The vehicle, the batteries used and the diagnostic devices used to assess the condition of the battery are all described in detail. Based on literature analysis and the observation of market trends, a fast and effective method of assessment of the technical condition of batteries in electric vehicles was proposed. The method was tested on the selected vehicle. The technical condition of the battery in the vehicle was assessed after 30,000 km and 4.5 years of operation.

State-of-health monitoring of lithium-ion batteries in electric vehicles by on-board internal resistance estimation

Game-based system dynamics simulation of deposit-refund scheme for electric vehicle battery recycling in China

A chip-to-chip inductive wireless power transmission system is proposed and the feasibility is experimentally demonstrated for the first time. The circuit realized 2.5mW power transmission at the output DC voltage of 0.5V using 700 times 700mum on-chip planar inductors for the transmitter and the receiver. Methods to optimize the circuit design about the maximum transmission power and the simulated optimization results are discussed

The original intention of wireless power transmission was to make the power supply more flexible, but compared with wired transmission, its efficiency has always restricted its application. Therefore, the performance characteristics of wireless power transmission have always been a research focus in wireless power transmission. As for induction power transmission, its coupling mechanism is the key part of the transmission system, and its optimal design directly affects the power, efficiency and transmission distance of the system. The research results of the coupling mechanism of an inductive power transmission system in recent years are reviewed, and the effects of coil structure, coupling mechanism material and coil parameter design on efficiency characteristics are analyzed. This paper analyzes the existing optimization methods and existing problems, and points out the direction for the optimal design of the coupling mechanism of a wireless power transmission system.

In view of the existing problems in DC traction power supply system and electric vehicle (EV) batteries charging system, a DC micro-grid is proposed: EV batteries are connected to DC traction power supply system via off-board bidirectional chargers, forming a ring DC micro-grid in a sub-region, in which EV batteries can be charged by DC traction power supply system and voltage of overhead contact system can be stabilized by the EV batteries charging and discharging system. A method that place ultra-capacitors in parallel with EV batteries is designed to improve system performance. Voltage droop control is adopted by parallel bidirectional chargers, which can achieve doublequadrant operation and avoid the circulating current as well. In the end, simulation results are presented to demonstrate the feasibility of this system.

Current status and perspectives on recycling of end-of-life battery of electric vehicle in Korea (Republic of)

The increase in global population has resulted in increased demand for stationary and portable energy, as well as increases in carbon dioxide emissions. The increases in greenhouse gases at the present trajectory will increase the global warming potential above the 2° threshold. At this threshold, it is anticipated that climate changes will adversely affect the land and sea masses. To minimize the potential of global warming and meet the increased energy demands, high-energy capacity lithium-ion (Li-ion) batteries in portable electronics and electric vehicles offer one potential solution. Current Li-ion chemistries focus on lithium cobalt oxide (LCO), lithium nickel cobalt manganese oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), lithium iron phosphate (LFP), and lithium titanium oxide (LTO) as cathodes and lithium metal (Li-metal) as an anode. Other semiconductor materials are used as alloying anodes (Si, Sn) that also include chalcogenides (S), metal halides (Br), and polymers. These materials enable the cell to maintain a high charge density through enhanced Li and electron transport, lesser volumetric expansion, material dissolution, and surface reactions between electrode and electrolyte generating heat. In part, battery thermal management is controlled using passive cooling in addition to liquid cooling. However, the widespread usage of Li-ion batteries in electric vehicles also presents a problem in end-of-life disposal and adverse effects on leaching of active materials into the water table. A life cycle assessment of Li material extraction and usage indicates that every watt-hour (Wh) of storage capacity utilizes 328 Wh of energy and generates 110 g carbon dioxide equivalent (CO2-eq.) emissions. The other components in the cathode, such as Ni and Co, may also pose toxicological adverse effects if released prematurely into the environment. The trend in battery design and evolution appears to indicate size and cost reduction; increased power density; recycling and transition to Li-S, Li-Air, or organic polymers to meet the anticipated energy demands; lower CO2-eq emissions; and electric vehicle demand by 2030.

A wide variety of applications can benefit from near-field wireless power transfer using coupled inductive links, such as wireless sensors and implantable microelectronic devices. The use of inductive power transmission is expected to see an explosive growth over the next decade as engineers try to cut the last cord from mobile electronics, small home appliances, and even electric vehicles [1]. The inductive link power transfer efficiency (PTE) is highly dependent of the loading of the receiver (Rx) coil, referred to as R L . As shown in Fig. 12.7.1a, magnetic resonance-based power transmission in the form of a 3-coil link has been proposed to maximize PTE for any given R L by transforming it to an optimal load, using k 34 variable [2,3]. Alternatively, an off-chip matching circuit has been used to transform R L [4]. However, these methods need either an additional coil or a network of off-chip capacitors and inductors, which add to the size/cost of Rx. Moreover, in the above applications, R L can change drastically during operation and there is a need for Rx to dynamically compensate for a wide range of R L to maintain high PTE.

Electric Vehicle (EV) battery technologies is a limiting factor for the wide spread diffusion of electric vehicles. EV battery’s energy density compared to fossil fuels is still very low, thus EV’s have still stringent driving range with voluminous, heavy and high cost batteries. Automotive OEM’s are trying to estimate the future of batteries to do their plans related to electric vehicle manufacturing. This article attempts to estimate the future of EV batteries and mainly that of Li_Ion, Li_S and Li_Air Technologies which seem to be the most promising Technologies as of today. The article explains in detail the methodology used, and the results with an estimation of future EV market as a result of the EV battery development time scale.

Electromobility is associated with the ever faster development and introduction of new electric vehicles to the market. They use an electric motor to drive the wheels of the vehicle and the necessary electricity is stored in traction batteries. Electric vehicles have a different construction than traditional vehicles i.e. powered by internal combustion engines. For this reason, the manner of use, maintenance and service are different. Familiarization with selected operational issues of electric vehicles positively affects the reliability of their usage as well as safety and comfort of driving. An important component of electric vehicles is the traction battery. Its proper operation influences the long-term preservation of the initial energy capacity and, thus, the range of the vehicle. The article presents the tests of the state of traction batteries of a small electrically powered city vehicle. The vehicle, the batteries and the diagnostic devices used to assess the condition of the battery are described in detail. Based on the literature analysis and the observation of market trends, a fast and effective method of assessment of the technical condition of batteries in electric vehicles was proposed. The method has been tested on the selected vehicle. The technical condition of the battery in the vehicle was assessed after 4.5 years of operation and 30,000 km mileage.

Accurate State of Health (SOH) diagnosis and forecasting are critical for ensuring the safety, efficiency, and longevity of batteries in electric vehicles (EVs). This novel research provides a comprehensive simulation-based comparative analysis of two Lithium Iron Phosphate (LFP) and Nickel Manganese Cobalt Oxide (NMC) batteries' degradation under realistic EV cycling conditions across an extended temperature range (25°C to 65°C). The design model used in this research, rigorously parameterized using published experimental data, tracks capacity fade and internal resistance growth, as well as coulombic efficiency decline, as key SOH indicators. Results of this novel and useful study demonstrate that both chemistries degrade faster with rising temperature, but NMC exhibits significantly accelerated aging above 50°C, reaching 80% SOH in fewer than half the cycles of LFP at 65°C. LFP maintains superior thermal resilience in a perfect manner, retaining higher SOH and lower resistance, including more stable coulombic efficiency across all temperatures. Achieved results also confirm and show greater degradation variability in NMC under thermal stress as well as increasing failure risk. This useful research quantifies critical temperature thresholds of batteries for end-of-life (SOH = 80%) and provides clear, data-driven guidance for battery selection and thermal management in EVs, particularly in hot climates or high-duty applications. By establishing a validated, multi-temperature simulation benchmark, this novel research work fills a major gap in chemistry-specific degradation forecasting and supports the design of adaptive battery management systems tailored to regional operating environments.

Second use of electric vehicle (EV) batteries used in the battery swapping station (BSS) is an effective way to improve economic benefits of the life span of the BSS and EV batteries. In this paper, we propose the physical structure of BSS for installing the energy storage system (ESS) of second use of EV batteries, and then establish the operation model of a BSS according to the operation mechanism between the internal components. In order to maximize the annual net present value of a BSS, the economic benefit model is established under the full consideration of the time of use (ToU) electricity price mechanism and the EV batteries charging demand. Finally, the proposed method is simulated, and the results show that according to the configuration results and operation strategies obtained by this paper, the economic benefits of BSS can be improved, and meanwhile, the volatility of the original load can be reduced.