Challenges and Barriers of Wireless Charging Technologies for Electric Vehicles

Electric vehicles could be a significant aid in lowering greenhouse gas emissions. Even though extensive study has been done on the features and traits of electric vehicles and the nature of their charging infrastructure, network modeling for electric vehicle manufacturing has been limited and unchanging. The necessity of wireless electric vehicle charging, based on magnetic resonance coupling, drove the primary aims for this review work. Herein, we examined the basic theoretical framework for wireless power transmission systems for EV charging and performed a software-in-the-loop analysis, in addition to carrying out a performance analysis of an EV charging system based on magnetic resonance. This study also covered power pad designs and created workable remedies for the following issues: (i) how power pad positioning affected the function of wireless charging systems and (ii) how to develop strategies to keep power efficiency at its highest level. Moreover, safety features of wireless charging systems, owing to interruption from foreign objects and/or living objects, were analyzed, and solutions were proposed to ensure such systems would operate as safely and optimally as possible

A Review on UAV Wireless Charging: Fundamentals, Applications, Charging Techniques and Standards

Unmanned Aerial Vehicles (UAVs) are becoming increasingly popular for applications such as inspections, delivery, agriculture, surveillance, and many more. It is estimated that, by 2040, UAVs/drones will become a mainstream delivery channel to satisfy the growing demand for parcel delivery. Though the UAVs are gaining interest in civil applications, the future of UAV charging is facing a set of vital concerns and open research challenges. Considering the case of parcel delivery, handling countless drones and their charging will become complex and laborious. The need for non-contact based multi-device charging techniques will be crucial in saving time and human resources. To efficiently address this issue, Wireless Power Transmission (WPT) for UAVs is a promising technology for multi-drone charging and autonomous handling of multiple devices. In the literature of the past five years, limited surveys were conducted for wireless UAV charging. Moreover, vital problems such as coil weight constraints, comparison between existing charging techniques, shielding methods and many other key issues are not addressed. This motivates the author in conducting this review for addressing the crucial aspects of wireless UAV charging. Furthermore, this review provides a comprehensive comparative study on wireless charging's technical aspects conducted by prominent research laboratories, universities, and industries. The paper also discusses UAVs' history, UAVs structure, categories of UAVs, mathematical formulation of coil and WPT standards for safer operation.publishedVersio

Inductive power transfer for automotive applications: State-of-the-art and future trends

The paper discusses the status of the development status of the inductive power transmission for automotive applications. This technology is, in fact, gaining the interest of electric vehicle manufacturers as an effective strategy to improve the market penetration of electric mobility. Starting from the origin of this technology, the paper presents an overview of the current state-of-the-art as well as the current research and industrial projects. Particular attention is devoted to the description of a prototypal system for the dynamic inductive power transmission whose goal is to extend the battery range by a fast partial recharging during the movement of the vehicle

Inductive Wireless Power Transfer Charging for Electric vehicles - A Review

Considering a future scenario in which a driverless Electric Vehicle (EV) needs an automatic charging system without human intervention. In this regard, there is a requirement for a fully automatable, fast, safe, cost-effective, and reliable charging infrastructure that provides a profitable business model and fast adoption in the electrified transportation systems. These qualities can be comprehended through wireless charging systems. Wireless Power Transfer (WPT) is a futuristic technology with the advantage of flexibility, convenience, safety, and the capability of becoming fully automated. In WPT methods resonant inductive wireless charging has to gain more attention compared to other wireless power transfer methods due to high efficiency and easy maintenance. This literature presents a review of the status of Resonant Inductive Wireless Power Transfer Charging technology also highlighting the present status and its future of the wireless EV market. First, the paper delivers a brief history throw lights on wireless charging methods, highlighting the pros and cons. Then, the paper aids a comparative review of different type’s inductive pads, rails, and compensations technologies done so far. The static and dynamic charging techniques and their characteristics are also illustrated. The role and importance of power electronics and converter types used in various applications are discussed. The batteries and their management systems as well as various problems involved in WPT are also addressed. Different trades like cyber security economic effects, health and safety, foreign object detection, and the effect and impact on the distribution grid are explored. Prospects and challenges involved in wireless charging systems are also highlighting in this work. We believe that this work could help further the research and development of WPT systems.publishedVersio

Design Optimization of Inductive Power Transfer Systems for Contactless Electric Vehicle Charging Applications

Contactless Electric Vehicle (EV) charging based on magnetic resonant induction is an emerging technology that can revolutionize the future of the EV industry and transportation systems by enabling an automated and convenient charging process. However, in order to make this technology an acceptable alternative for conventional plug-in charging systems it needs to be optimized for different design measures. Specifically, the efficiency of an inductive EV charging system is of a great importance and should be comparable to the efficiency of conventional plug-in EV chargers. The aim of this study is to develop solutions that contribute to the design enhancement of inductive EV charging systems. Specifically, generalized physics-based design optimization methods that address the trade-off problem between several key objectives including efficiency, power density, misalignment tolerance, and cost efficiency considering critical constraints are developed. Using the developed design methodology, a 3.7kW inductive charging system with square magnetic structures is investigated as a case study and a prototype is built to validate the optimization results. The developed prototype achieves 93.65% efficiency (DC-to-DC) and a power density of 1.65kW/dm3. Also, self-tuning power transfer control methods with resonance frequency tracking capability and bidirectional power transfer control are presented. The proposed control methods enhance the efficiency of power converters and reduce the Electromagnetic Interference (EMI) by enabling soft-switching operations. Several simplified digital controllers are developed and experimentally implemented. The controllers are implemented without the use of DSP/FPGA solutions. Experimental tests show that of the developed simplified controllers can effectively regulate the power transfer around the desired value. Moreover, the experiments show that compared to conventional converters, the developed converters can achieve 4% higher efficiency at low power levels. Moreover, enhanced matrix converter topologies that can achieve bidirectional power transfer and high efficiency with a reduced number of switching elements are introduced. The self-tuning controllers are utilized to design and develop control schemes for bidirectional power transfer regulation. The simulation analyses and experimental results show that the developed matrix converters can effectively establish bidirectional power transfer at the desired power levels with soft-switching operations and resonance frequency tracking capability. Specifically, a direct three-phase AC-AC matrix converter with a reduced number of switches (only seven) is developed and built. It is shown that the developed converters can achieve efficiencies as high as 98.54% at high power levels and outperform conventional two-stage converters

Review on stationary CPT technologies and coil designs for EVs

In the recent decade, the driving range of pure EVs with zero emission target has become a popular topic as the massive battery requirement for longer distance travels means higher vehicle cost and longer time of recharging periods. Stationary CPT charging solutions could be an alternative to reduce EVs weight, size and energy storage unit costs. Fortunately, with progressive success of low-power CPT charging applications proposed to be commercially produced in the past decade, hundreds of kilowatts level high-power CPT charging techniques for EVs are more and more expected to be an optimally suitable solution for recharging EV batteries, providing higher propulsion and delivering continuously longer driving range in the next generations of the EVs. The idea of deploying inductive coupling for EVs has acquired a lot of attentions in the last decade due to the contributions and advancements of power electronics, switching power supply, semiconductors, microprocessors, electrochemistry, material sciences, control technologies, electromagnetics and so on, despite many challenges to be addressed including EV manufacturing integration with CPT system under the chassis, infrastructure difficulties, system maintenance on both vehicle and transmitting ground sides, actual CPT performance with real-time coupling on real-world road. In order to ensure the realization and enhance the sustainability in transportation sector with the emerging CPT ideas, currently the stationary CPT charging solutions based on inductive power transfer (IPT) have been developed from laboratory level as a first step to the practical tests of commercial realizations. In a few industrial fields nowadays, some of the proposed CPT technologies with specific coupler coil designs have been expected for real-world applications. This article presents a state of the art of the CPT technologies and focuses on reviewing current coil designs for high-power contactless energy transfer for EVs in the literature

Improved Design of Wireless Electrical Energy Transfer System for Various Power Applications

This thesis introduces a state-of-the-art review of existing wireless power transfer (WPT) technologies with a detailed comparison and presents the limitations of the inductive power transfer system through simulation and practical analyses. This thesis also presents the expanded use of the high-frequency analysis tool, known as FEKO, and the novel application of frequency response analyser (FRA) with various simulations and practical demonstrations for enhancing the design and maintenance of WPT systems

Review on Key Factors of Wireless Power Transfer Technology for Electric Vehicles

Electric vehicles (EVs) have become an alternative option for a clean energy society. A new charging technology which is wireless charging has been developed to satisfy the limitations of EVs which are the electric drive range and battery storage. Companies like Tesla, BMW, and Nissan have already started to develop wireless charging for EVs. This paper presents a literature review on wireless charging of EVs. The existing technologies for Wireless Power Transfer (WPT) system are summarized for different power applications. Coil design plays the most vital role in the WPT system so the different coil design with the transferred efficiency is reviewed. The other important parameters and technical components like significant factors of WPT system, track layout of dynamic wireless charging, foreign object detection method, and position alignment method that are affecting the efficiency of the wireless charging system are also discussed. Lastly, health and safety concerns for human beings and living things are investigated

Challenges of Inductive Electric Vehicle Charging Systems in both Stationary and Dynamic Modes

Inductive power transfer as an emerging technology has become applicable in wide power ranges including Electric Vehicle, Electric Aircraft, wheelchair, cellphone, scooter and so on. Among them, inductive Electric Vehicle (EV) charging has gained great interest in the last decade due to many merits namely contactless technology, more convenience, full automotive charging process. However, inductive EV charging systems could bring about so many issues and concerns which are addressed in this dissertation. One of the critical challenges addressed in this dissertation is a virtual inertia based IPT controller to prevent the undesirable dynamics imposed by the EVs increasing number in the grid. Another adverse issue solved in this dissertation is detecting any metal object intrusions into the charging zone to the Inductive Power Transfer (IPT) systems before leading to heat generation on the metal or risk of fire. Moreover, in this dissertation, a new self-controlled multi-power level IPT controller is developed that enables EV charging level regulation in a wide range of power; suitable for different applications from golf-cart charging system (light duty EV) to truck (heavy duty EV). The proposed controller has many merits including easy to be implemented, cons-effective, and the least complexities compared to conventional PWM methods. Additionally, in this dissertation, the online estimation of IPT parameters using primary measurement including coupling factor, battery current and battery voltage is introduced; the developed method can find immediate applications for the development of adaptive controllers for static and dynamic inductive charging systems. Finally, the last objective of this research is physics-based design optimization techniques for the magnetic structures of inductive EV charging systems for dynamic application (getting charged while in motion). New configuration of IPT transmitting couplers with objective of high-power density, low power loss, low cost and less electromagnetic emission are designed and developed in the lab

Optimization of 8-Plate Multi-Resonant Coupling Structure Using Class-E\u3csup\u3e2\u3c/sup\u3e Based Capacitive-Wireless Power Transfer System

Capacitive-wireless power transfer (CPT) effectively charges battery-powered devices without a physical contact. It is an alternative to inductive-wireless power transfer (IPT) which is available in the present market. Compared with IPT, CPT offers flexibility in designing the coupling section. Because of its flexibility, CPT utilizes various coupling methods to enhance the coupling capacitance. Misalignment is a common issue in any WPT system. Among IPT and CPT, IPT has better performance for misalignments, but it requires bulk and expensive ferrite core to attain a high coupling coefficient. This work focuses on designing a CPT system to minimize the impact of misalignments. In this research, a novel 8-plate multi-resonant Class-E2 CPT system is developed to improve the performance of the CPT system for misalignments. The proposed CPT model expands the resonant frequency band, which results in better performance for misalignments compared with the regular 4-plate CPT system. The 8-plate coupling structure is designed to charge a 100 Ah drone battery. For this application, the coupling is formed when the drone lands on the capacitive- wireless charging pad. This work also presents the analysis of several dielectric materials with different dielectric constants. A well-designed capacitive coupler can effectively limit harmonics during the interaction between transmitter and receiver. Also, the effect of coupling plate shape is identified on the CPT system. The hardware tests indicate the round-shaped plates have better stability in coupling capacitance with the variation in frequency. The effect of misalignments is studied through the impedance tracking of the Class-E2 power converter. Impedance plots for 50 μH, and 100 μH resonant inductors are used to determine input current peak for each case. Additionally, hardware tests are performed to study the variation of input current and output voltage for a range of frequencies. The test results indicate the efficiency at optimal impedance point for a resonant inductor with 50 μH is 8% higher compared to the CPT with a 100 μH resonant inductor which highlights the effects of the resonant inductor on efficiency. The zero-voltage-switching (ZVS) limits are also identified for varying frequencies and duty cycles. Later in this research, the optimal design of the Class-E rectifier is identified to enhance the power transfer. Several cases were considered to investigate the impact of the secondary inductor on the output voltage and the ZVS property. Hardware tests validate that under optimal conditions the efficiency of the Class-E2 based CPT system improves by 18% compared with Ar \u3e\u3c 1. Further work presents the advantages of 8-plate multi-resonant coupling for misalignments. The proposed model has a simple design procedure which enhances the power flow from the inverter to the rectifier section. The hardware results of the proposed 8-plate multi-resonant coupling show an increase in efficiency to 88.5% for the 20.8 W test, which is 18% higher than regular 4-plate coupling. Because of the wider resonant frequency band [455- 485 kHz], compared with regular 4-plate coupling, the proposed design minimized the output voltage drop by 15% for 10% misalignment. Even for large misalignments, 8-plate improves the CPT performance by 40% compared with 4-plate coupling