DESIGN AND CONTROL OF INDUCTIVE POWER TRANSFER SYSTEM FOR ELECTRIC VEHICLE CHARGING

During the last decades, public awareness of the environmental, economic and social consequences of using fossil fuels has considerably grown. Moreover, not only the supply of fossil resources is limited, but also the environmental impact represents a relevant issue, so leading to an increased consideration of clean and renewable alternatives to traditional technologies. The automotive industry has shown a growing interest in electric and hybrid electric vehicles. However, the transition to all-electric transportation is now limited by the high cost of the vehicles, the limited range and the long recharging time. Distributed Inductive Power Transfer (IPT) systems can be the solution to the range restrictions of EVs by charging the vehicle while driving thanks to, a set of loosely coupled coils, so also reducing required battery size as well as overall cost of the vehicle. The concept of wireless power transfer via magnetic induction was introduced two decades ago. Nowadays, this technology is becoming more efficient and more suitable for new applications. This dissertation made an effort to address the requirements of IPT EV battery charging system with high efficiency and good tolerance to misalignment. A survey of a typical IPT for EV application has been reported, while a concentrated DD-BP solution has been proposed in order to enhance the IPT charging system capability of transferring power to a stationary EV with good efficiency and good tolerance to movement. The current trend in EV battery charging application is represented by the lamped coil system, whose different structures have been reviewed. On the contrary, this thesis presented the design of a charging pad magnetic structure, called Double D pad combined with a Bipolar secondary pad, in order to enhance coupling performance. A finite element magnetic analysis has been performed in order to obtain the electric parameters of the proposed magnetic coupler. Furthermore, a mathematical model has been developed by considering the different sides of the system. The mathematical model allows to accurately predict the behavior of inductive coils and coreless transformer. A set of simulation has been carried out in order to compare the analytical and simulated results. The proposed EV IPT system has shown the feasibility of using fixed frequency, single pick up system to transfer power efficiently across a large air gap, with variable coupling. This result has been reached by means of proper design of the charging pad magnetics, of tuning network and of a pick-control based on a buck boost converter topology.The research presented in this work was an attempt to address the problems related to the design and control of an IPT system, in order to achieve the power transfer with good efficiency, also having a wider tolerance to physical movement and changes in the coupling with respect to conventional loosely coupled systems

An Integrated Approach for Dynamic Charging of Electric Vehicles by Wireless Power Transfer - Lessons Learned from Real-Life Implementation

The aim of this paper is to introduce a complete fast dynamic inductive charging infrastructure from the back-office system (EV management system) up to the Electric Vehicle (EV) (inductive power transfer module, positioning mechanism, electric vehicle modifications) and the EV user (User interface). Moreover, in order to assess the impact of the additional demand of inductive charging on the grid operation, an estimation of the 24-hour power profile of dynamic inductive charging is presented considering, apart from the road traffic, the probability of the need for fast charging, as well as the specifications of the proposed solution. In addition, an energy management system is presented enabling the management of the operation of the inductive charging infrastructure, the interaction with the EV users and the provision of demand response services to different stakeholders. The proposed dynamic inductive charging approach has been demonstrated within a real urban environment in order to provide useful insights regarding the experience gained from a real-field trial. The relevant practical conclusions are also discussed in this paper. Finally, a cost/benefit analysis, according to the Discounted Cash Flow (DCF) principles, is performed in order to assess the economic viability of the proposed solution.This work was supported by the European Commission within the 7th Framework Programme, Project FastInCharge under the Grant Agreement: 31428

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

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

Energy Efficiency Analysis through Misalignment on New Design of Hexagonal Coil Array in Wireless Power Transfer

The global transportation revolution accelerates the growth of the Electric Vehicle (EV) market. Wireless Power Transfer Technology (WPT) is part of an alternative solution to replace charging by cable. In its implementation the driver's parking behavior affects Power Transfer Efficiency (PTE) due to frequently misalignment. A new coil array design proposed to optimize PTE and reduce the size of receiver coil. Receiver and transmitter circuits designed to simulate parking conditions and parking lots in small scale settings to get PTE data. Experimental results show that PTE increased by 10% in the center of the coil design and 82% during misalignment on a radius array against single loop coil. In the area of Misalignment tangential boundary, efficiency increased by 5-10% compared to circular coil arrays. The proposed novel coil series achieves a higher overall PTE than a single coil design and an increase in PTE in the tangential boundary misalignment when compared to circular coil arrays

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

Simultaneous wireless power and data transfer for electric vehicle charging: a review

Wireless charging of Electric Vehicles (EVs) has become an important research topic in recent years. During the wireless charging process, wireless data exchange must take place between the EV and the charging station. Battery status, current and voltage of the charger or the EV identification may be required on the primary side in order for the system to operate properly. This data exchange can be carried out through commercial wireless communication solutions such as Bluetooth, 802.11 or ZigBee. However, these technologies introduce cybersecurity problems, high and variable transmission delays and possible connection losses during communication. To address these issues, numerous solutions have been proposed based on wireless data transmission through the wireless power transfer circuit. This paper gives a comprehensive review of the different issues that need to be considered for simultaneous wireless power and data transmission (SWPDT) for wireless EV charging applications. This context represents a challenge for SWPDT due to the power levels and the high probability of operating with notable misalignments or even with the EV on move. Specifically, a classification of SWPDT systems is described, and six different criteria to consider when designing a SWPDT system are analysed for EVs. The suitability of different system configurations is evaluated according to three representative use cases: (i) providing maximum efficiency, (ii) synchronisation for bidirectional wireless chargers and (iii) dynamic charging. We have also analysed the feasibility of using the Open Charge Point Protocol (OCPP) together with ISO 15118, which is the most popular communication protocol used in EV charging infrastructures.Funding for open access charge: Universidad de Málaga/CBUA. Funding for this project was partially provided by the Spanish Ministerio de Educación, Cultura y Deporte, José de Castillejo programme (Mobility Grant CAS 17-00318), the Spanish Ministerio de Ciencia e Innovacion (MICINN) project PID2019-110531-RA-I00/AEI/10.13039/501100011033 of the ”Proyectos de I+D+i - RTI Tipo A” and by the University of Malaga (project D5-2021-09)

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

Analysis of rectangular EV inductive charging coupler

© 2017 IEEE. The number of commercial electric vehicles has increased significantly in recent years. However, there are still limited recharging facilities for EVs. Wireless charging offers an alternative way to recharge with more flexibility and convenience. The wireless transformer/coupler is the key component in electric vehicle wireless charging. The maximum power transfer capability is limited by the coupler. In order to reach desired power transfer level, the parameters of the wireless transformer should be analyzed. The wireless power transfer system design also requires accurate coupler parameters. In this paper, rectangular pads with different size of ferrite bars were analyzed in finite element analysis software. The prototype was built to valid the simulation result