Impact of Coil Misalignment in Data Transmission over the Inductive Link of an EV Wireless Charger

The penetration rate of electric vehicles (EVs) will experience a relative increment in the future, so easy to use ways to recharge will be demanded. In this sense, wireless charging represents a safe charging method that minimises user intervention. In a similar way to conductive charge, wireless charging requires some information exchange between the charger primary side and secondary side (battery) for safety and operational reasons. Thus, wireless chargers depend on a communication system for their controlled and correct operation. This paper analysed the communication performance of a wireless EV charger in which the communiction device is part of the wireless power transfer system. Particularly, this work studies how the communication system reacts to power coil displacements, which commonly occur in their conventional performance. The results show that the compensation topology selected to ensure the resonant operation clearly impacts on the communication performance. In particular, the theoretical model and the simulation results demonstrate that the asymmetrical compensation topologies are more stable in terms of the wireless communication channel capacity

Parameter identification of wireless power transfer systems using input voltage and current

Wireless power transfer (WPT) systems based on the use of resonators with high quality factors are highly sensitive to the parameters of the resonant tanks. While the inductance terms can be theoretically calculated, the mutual inductance terms require very accurate measurements of the coil dimensions, locations and orientations. Slight deviations of these measurements could therefore lead to significant errors. In addition, capacitors have fairly large tolerance in terms of their capacitance, making it difficult to assume their rated values in the determination of the optimal operating frequency of the WPT systems. In this paper, a parameter identification method for WPT systems based on the measurements of the input voltage and current is presented. Using an evolutionary algorithm, accurate parameter values required for modeling the WPT system can be determined. This method has been successfully illustrated in a 3-coil WPT system. Good agreements between calculated and measured parameters have been achieved. © 2014 IEEE.published_or_final_versio

Technology of swallowable capsule for medical applications

Medical technology has undergone major breakthroughs in recent years, especially in the area of the examination tools for diagnostic purposes. This paper reviews the swallowable capsule technology in the examination of the gastrointestinal system for various diseases. The wireless camera pill has created a more advanced method than many traditional examination methods for the diagnosis of gastrointestinal diseases such as gastroscopy by the use of an endoscope. After years of great innovation, commercial swallowable pills have been produced and applied in clinical practice. These smart pills can cover the examination of the gastrointestinal system and not only provide to the physicians a lot more useful data that is not available from the traditional methods, but also eliminates the use of the painful endoscopy procedure. In this paper, the key state-of-the-art technologies in the existing Wireless Capsule Endoscopy (WCE) systems are fully reported and the recent research progresses related to these technologies are reviewed. The paper ends by further discussion on the current technical bottlenecks and future research in this area

Recent progress in mid-range wireless power transfer

This is a review paper describing recent progress of mid-range applications of wireless power transfer. Starting from Tesla's principles of wireless power transfer a century ago, it outlines magneto-inductive research activities in the last decade on wireless power transfer with the transmission distance in the order of or greater than the coil dimension. It covers the basic characteristics of 2-coil systems, 4-coil systems, systems with relay resonators and the wireless domino-resonator systems. © 2012 IEEE.published_or_final_versio

Tracking and dynamic tuning of a wireless powered endoscopic capsule

This work presents an inductive wireless power transfer system for powering an endoscopy capsule supplying energy to power electronic devices allocated inside a capsule of ≈26.1 mm × 9 mm. A receiver with three coils in quadrature with dimensions of ≈9 mm × 9 mm × 10 mm is located inside the capsule, moving freely inside a transmitter coil with 380 mm diameter through translations and revolutions. The proposed system tracks the variations of the equivalent magnetic coupling coefficient compensating misalignments between the transmitter and receiver coils. The power on the load is estimated and optimized from the transmitter, and the tracking control is performed by actuating on a capacitance in the matching network and on the voltage source frequency. The proposed system can prevent load overheating by limiting the power via adjusting of the magnitude of voltage source VS. Experimental results with uncertainties analysis reveal that, even at low magnetic coupling coefficients k ranging from (1.7 × 10−3 , 3.5 × 10−3 ), the power on the load can be held within the range of 100–130 mW. These results are achieved with any position of the capsule in the space, limited by the diameter of the transmitter coil and height of 200 mm when adjusting the series capacitance of the transmitter in the range (17.4, 19.4) pF and the frequency of the power source in the range (802.1, 809.5) kHz

Pregled stanja u području bezkontaktnog prijenosa električne energije: primjene, izazovi i trendovi

Methods of contactless electrical power transfer technologies have been surveyed and results are presented here. In this among, the inductive based contactless electrical power transfer systems are investigated in more detail. The principles, structures and operations of the systems as well as their methods presented in the literature are reviewed and their applications are explored. Also, current challenges and opportunities and future trends are noted. An effective index is proposed to compare different contactless power transfer systems describing their present statuses and the future trends. Finally, some remarks and recommendations regarding future studies are proposed.U radu je dan prikaz različitih tehnologija u području bezkontaktnog prijenosa električne energije. U radu je naglasak na indukcijom baziranim sustavima bezkontaktnog prijenosa električne energije. Pregledom literature utvrðeni su koncepti, strukture i način rada pojedinih sustava bezkonaktnog prijenosa kao i njihove primjene. Također, zabilježeni su trenutni izazovi, prilike i trendovi. Predložen je efektivni indeks za vrednovanje sustava bezkontaktnog prijenosa električne energije s ciljem komparativne analize različitih sustava opisanih trenutnim statusom i trendovima. Konačno, dan je kritički osvrt i predložene su preporuke za buduće studije

Design and Implementation of a Fixed-frequency Inductive Power Transfer System

Inductive power transfer (IPT) technology has gained immense interest for battery charging applications. IPT proves to be particularly efficient and suitable for high-power applications (≈1-20kW). This makes IPT an effective alternative for charging large batteries of electric vehicles (EVs), especially large electric transit vehicles, such as trains, trams, and buses. Because of the trend that this technology is having, it is important to understand the general characteristics and its applications. Nowadays, it is not a secret that IPT technology is and will continue revolutionizing the industry and our society. The future vision is to change the way electricity has been observed since its discovery: through wires. The main objective of this thesis is to study in details the fundamentals of IPT technology and analyze two principal stages of the system: the power supply and the resonant circuit, in order to design an IPT system using effective techniques, which will improve its performance. Additionally, the thesis helps identify and suggest a design procedure that can benefit and motivate future work on this technology. Moreover, the thesis presents a prototype setup that was built in the laboratory, in order to validate the theoretical analysis and simulation results. The thesis is structured into four main parts; the first part reviews the concepts of IPT systems, the different topologies, the explanation of important design considerations, and finally, presents initial simulation results. The second part explains the characteristics of the power supply in IPT systems, the control techniques to regulate the power flow, the explanation of a proposed control strategy, and the simulation results. The third part presents the experimental test setup and related results. Finally, the fourth part presents the conclusions and suggested future work