Wireless Energy Transfer with Three-Phase Magnetic Field System: Experimental Results

In this paper a three-phase magnetic field system is applied to the wireless power transfer system. The research is directed not only to the distribution of the magnetic field but to optimize the energy transfer efficiency, and to reduce the electromagnetic field influence to the surroundings. The development of the future intelligent transportation system depends on the electric mobility, namely, the individual or the public electric vehicles. It is crucial to achieve progress in the batteries and the battery charging, especially through a wireless power transfer technology. The study of the magnetic field is important in this technology. The energy transfer efficiency depends of the alignment, the size of the coils, the spatial orientation of the magnetic field, the detachment and the tilt between the windings

Three-phase magnetic field tested in wireless power transfer system

This paper presents a magnetic field three dimensional mapping produced by a threephase prototype for wireless power transfer. The presented magnetic field mapping is a contribution to improve the design of electric vehicles battery chargers using the wireless power transfer. To collect the magnetic field data, a prototype was built, in order to support the tests. The prototype primary is an electrical three-phase system that allows to be connected electrically and geometrically in star or delta. The losses due to the magnetic field dispersion and the generated interferences in the surrounding equipment or in human body are discussed. The different standards organizations related to electric vehicles battery chargers are presented. Finally the magnetic field influence on the human body is addressed

Insights into tunnel FET-based charge pumps and rectifiers for energy harvesting applications

In this paper, the electrical characteristics of tunnel field-effect transistor (TFET) devices are explored for energy harvesting front-end circuits with ultralow power consumption. Compared with conventional thermionic technologies, the improved electrical characteristics of TFET devices are expected to increase the power conversion efficiency of front-end charge pumps and rectifiers powered at sub-µW power levels. However, under reverse bias conditions the TFET device presents particular electrical characteristics due to its different carrier injection mechanism. In this paper, it is shown that reverse losses in TFET-based circuits can be attenuated by changing the gate-to-source voltage of reverse-biased TFETs. Therefore, in order to take full advantage of the TFETs in front-end energy harvesting circuits, different circuit approaches are required. In this paper, we propose and discuss different topologies for TFET-based charge pumps and rectifiers for energy harvesting applications.Peer ReviewedPostprint (author's final draft

Current Interactions Mitigation in 3-Phase PFC Modular Rectifier through Differential-Mode Choke Filter Boost Converter

In this paper, a new way to mitigate the current interactions, is proposed. The problem of current interactions arises when a modular three-phase (3-phase) rectifier (three single-phase modules) with boost converter for power factor correction (PFC) is used. A new differential-mode choke filter is implemented in the developed boost converter. The choke here is a specially made differential inductor in the input of the boost converter, that eliminates the known current interactions. To prove the new concept, a study of the level of mitigation of the current interactions is presented. The control is operated in continuous driving mode (CCM), and the popular UC3854B circuit was used for this. The rectifier proposal is validated through a set of simulations performed on the PSIM 12.0 platform, as well as the construction of a prototype. With the results obtained, it is confirmed that the differential-mode choke filter eliminates the current interactions. It is observed that at the input of the rectifier, a sinusoidal alternating current with a low level of harmonic distortion is consumed from the grid. The sinusoidal shape of the phase current, proves that a better power factor, capable of meeting the international standards is obtained, and proves that the circuit in its initial version, is operational. This proven result promises a good PFC operation, to guarantee the better quality of the electrical energy, being able to be applied in systems that require a high PFC, e.g. in battery charging, wind systems, or in aeronautics and spacecrafts

A battery-less, self-sustaining RF energy harvesting circuit with TFETs for µW power applications

This paper proposes a Tunnel FET (TFET) power management circuit for RF energy harvesting applications. In contrast with conventional MOSFET technologies, the improved electrical characteristics of TFETs promise a better behavior in the process of rectification and conversion at ultra-low power (µW) and voltage (sub-0.25 V) levels. RF powered systems can not only benefit from TFETs in front-end rectifiers by harvesting the surrounding energy at levels where conventional technologies cannot operate but also in the minimization of energy required by the power management circuit. In this work we present an energy harvesting circuit for RF sources designed with TFETs. The TFET controller emulates an adequate impedance at the output of the rectifier in order to allow maximum transfer of power from the RF source to the input of the boost converter. The output load is activated once the output capacitor reaches a voltage value of 0.5 V. The results show an efficiency boost of 89 % for an output load consuming 1 µW with an available RF power of -25 dBm.Postprint (published version

Optimal controller design for non-affine nonlinear power systems with static var compensators for hybrid UAVs

s Mr. S. Venkataiah is thankful to the University Grants Commission, New Delhi, for the award of UGC-BSR-RFSMS Junior Research Fellowship. Dr. S. Uthanna thankful to the University Grants Commission for the award of UGC-BSR Faculty Fellowship.A generalized non-affine nonlinear power system model is presented for a single machine bus power system with a Static Var Compensator (SVC) or State Var System (SVS) for hybrid Unmanned Aerial Vehicles (UAVs). The model is constructed by differential algebraic equations on the MATLAB-Simulink platform with the programming technique of its S-Function. Combining the inverse system method and the Linear Quadratic Regulation (LQR), an optimized SVC controller is designed. The simulations under three fault conditions show that the proposed controller can effectively improve the power system transient performance.publishersversionpublishe

Electric Vehicle Battery Charger: Wireless Power Transfer System Controlled by Magnetic Core Reactor

This paper presents a control process and frequency adjustment based on the magnetic core reactor for electric vehicle battery charger. Since few decades ago, there have been significant developments in technologies used in wireless power transfer systems, namely in battery charger. In the wireless power transfer systems is essential that the frequency of the primary circuit be equal to the frequency of the secondary circuit so there is the maximum energy transfer. The magnetic core reactor allows controlling the frequencies on both sides of the transmission and reception circuits. Also, the assembly diagrams and test results are presented

Electromagnetic Interference from a Wireless Power Transfer System: Experimental Results

The paper presents experimental results of measurement and analysis of the electromagnetic fields generated by wireless power transfer system and their possible interaction on data transmission channel. The energy transfer efficiency depends strongly both on the operation of the power transmitter and the operation of the receiver as well. Currently, in the Faculty of Science and Technology of the University Nova high power wireless power transfer systems are being constructed. For the coordination and optimization of the transmitter and receiver of the power transfer system, a set of microcontrollers is in development. The microcontrollers’ mutual communication is of extreme importance especially when high intensity fields will induce highly undesired influence. The two (or more) controllers take the responsibility of the control in the transmitting and the receiving sides, correspondingly. The controllers are supposed to communicate with each other through a RF data channel. The WPT system with the induced electromagnetic interference voltages and currents may influence or completely disrupt the communication which will be a severe problem

Electric Vehicle Battery Charger Controlled by Magnetic Core Reactor to Wireless Power Transfer System

This paper presents a control process and frequency adjustment based on the Magnetic Core Reactor prototype. For the past decades, there has been significant development in the technologies used in Wireless Power Transfer systems. In the Wireless Power Transfer systems it is essential that the operating frequency of the primary circuit be equal to the resonant frequency of the secondary circuit so there is the maximum energy transfer. The Magnetic Core Reactor allows controlling of the frequencies on both sides of the transmission and reception circuits. In addition, the assembly diagrams and test results are presented

Wireless Power Transfer Impact on Data Channel

Trabalho apresentado no 23rd International Symposium on Power Electronics, Electrical Drives, Automation and Motion (Speedam, 2016), 22-24 junho de 2016, Capri, ItáliaThis paper presents measurement results and analysis of the interference produced by the high-power electromagnetic field in a wireless energy transfer system. Through this analysis it is expected to be possible to evaluate the influence of the strong electromagnetic field on the data transmission channel. The wireless power transfer aimed at electric vehicles battery charging receives a great deal of attention in the recent years. However, the performance of those systems depends on the exchange of information between the transmitter and the receiver, e.g. vehicle identification, frequency, required power, payment information. Thus, it is essential to ensure that the electromagnetic interference, generated by the wireless power transfer system will not influence or disrupt the communication between the transmitter and the receiver.N/