The Experts below are selected from a list of 240 Experts worldwide ranked by ideXlab platform
Yoichi Hori - One of the best experts on this subject based on the ideXlab platform.
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sensorless vehicle detection using voltage pulses with envelope model for in motion wireless power transfer system
Conference of the Industrial Electronics Society, 2019Co-Authors: Keiichiro Tokita, Katsuhiro Hata, Hiroshi Fujimoto, Yoichi HoriAbstract:In the application of in-motion wireless power transfer (WPT) for electric vehicles (EVs), the transmitter coil on the road has to detect the vehicle before the power transmission starts. Search pulse method in a previous study can judge the existence of vehicles by measuring the Transmitting-Side current and comparing it with the threshold value. However, the design method of the threshold value in a theoretical way has yet to be shown. Here we show a novel calculation method of the threshold value by using the envelope model of the transient response of current. The preciseness of the proposed method was verified by the full-scale experiment and the effectiveness of the detection algorithm improved.
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IECON - Sensorless Vehicle Detection Using Voltage Pulses with Envelope Model for In-motion Wireless Power Transfer System
IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society, 2019Co-Authors: Keiichiro Tokita, Katsuhiro Hata, Hiroshi Fujimoto, Yoichi HoriAbstract:In the application of in-motion wireless power transfer (WPT) for electric vehicles (EVs), the transmitter coil on the road has to detect the vehicle before the power transmission starts. Search pulse method in a previous study can judge the existence of vehicles by measuring the Transmitting-Side current and comparing it with the threshold value. However, the design method of the threshold value in a theoretical way has yet to be shown. Here we show a novel calculation method of the threshold value by using the envelope model of the transient response of current. The preciseness of the proposed method was verified by the full-scale experiment and the effectiveness of the detection algorithm improved.
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coupling coefficients estimation of wireless power transfer system via magnetic resonance coupling using information from either Side of the system
IEEE Journal of Emerging and Selected Topics in Power Electronics, 2015Co-Authors: Vissuta Jiwariyavej, Takehiro Imura, Yoichi HoriAbstract:Wireless power transfer via magnetic resonance coupling method has opened a new possibility to the electric vehicle system. It allows the wireless charging system of moving vehicles, using charging lanes. However, although the efficiency of power transmission is relatively high, the efficiency still depends on displacement of coils. There have been several researches on methods to maintain power transmission at the highest efficiency. However, in such systems, the information on system parameter especially coupling coefficients is needed, and in the charging lane system, such information is unlikely to be obtainable without a communication system. Therefore, it has come to attention that parameter estimation is a crucial factor to implement a charging lane system. This paper presents derivations of equations for estimating coupling coefficients in several configurations of wireless power transfer system, using information from only one Side, either the Transmitting Side or the receiving Side, of the system. The presented equations are both applicable to the case of single receiving coil and are also generalized for the case of multiple receiving coils. Each equation is verified by both simulations and experiments. An experimental system of the coupling coefficient estimation system is constructed for estimation from the receiving Side using a dc/dc converter.
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automated impedance matching system for robust wireless power transfer via magnetic resonance coupling
IEEE Transactions on Industrial Electronics, 2013Co-Authors: Teck Chuan Beh, Takehiro Imura, Masaki Kato, Yoichi HoriAbstract:Recently, a highly efficient midrange wireless transfer technology using electromagnetic resonance coupling has been proposed and has received much attention due to its practical range and efficiency. The resonance frequency of the resonators changes as the gap between the resonators changes. However, when this technology is applied in the megahertz range, the usable frequency is bounded by the industrial, scientific, and medical (ISM) band. Therefore, to achieve maximum power transmission efficiency, the resonance frequency has to be fixed within the ISM band. In this paper, an automated impedance matching (IM) system is proposed to increase the efficiency by matching the resonance frequency of the resonator pair to that of the power source. The simulations and experiments verify that the IM circuits can change the resonance frequency to 13.56 MHz (in the ISM band) for different air gaps, improving the power transfer efficiency. Experiments also verified that automated IM can be easily achieved just by observing and minimizing the reflected wave at the Transmitting Side of the system.
M. Mito - One of the best experts on this subject based on the ideXlab platform.
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Distributed multilink system for very-high-speed data link control
IEEE Journal on Selected Areas in Communications, 1993Co-Authors: T. Akaike, K. Saito, K. Ishakawa, M. MitoAbstract:A protocol control system architecture that provides very high processing performance for gigabit-per-second data communication in a broadband network is described. The architecture connects protocol controllers in parallel and uses a distributed multilink method that features a distributed algorithm for allocating transmission on the Transmitting Side and a resequencing algorithm on the receiving Side. The system performance and the influence of transmission errors caused by cell loss in an asynchronous transfer mode network are evaluated. It is shown that by reducing each controller's distributing overhead, the system increases throughput up to 90 times that achieved when using a single controller. >
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A very high speed data link control system using multiple protocol controllers
[Conference Record] SUPERCOMM ICC '92 Discovering a New World of Communications, 1Co-Authors: T. Akaike, K. Ishikawa, K. Saito, M. MitoAbstract:A protocol control system architecture that provides excellent processing performance for data communications and utilizes a high speed network such as asynchronous transfer mode (ATM) is discussed. The system consists of multiple protocol controllers (PCs) connected in parallel and employs the distributed multilink method, in which the multilink procedure is distributed to each PC. The method features a distributed algorithm for transmission allocation at the Transmitting Side and a resequence algorithm at the receiving Side. Characteristics of the method are analyzed and the system performance is evaluated. The system can provide a 90-fold performance improvement over a single PC. >
Yi-ching Huang - One of the best experts on this subject based on the ideXlab platform.
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VTC Spring - An Improved Constellation Extension Scheme for PAPR Reduction in OFDM Systems
2011 IEEE 73rd Vehicular Technology Conference (VTC Spring), 2011Co-Authors: Chin-liang Wang, Shun-sheng Wang, Yi-ching HuangAbstract:A number of peak-to-average power ratio (PAPR) reduction techniques have been proposed for orthogonal frequency division multiplexing (OFDM) systems; however, most of them require Transmitting Side information and thus reduce the bandwidth efficiency. The existing constellation extension (CE) schemes do not need to transmit Side information. In this paper, we propose an improved CE scheme for PAPR reduction of OFDM signals with 16-QAM modulation. The proposed CE scheme has four extendable constellation points, the four corners in the 16-QAM constellation, and each extendable constellation point has two possible extended constellation points. The proposed CE scheme, when compared with previous related CE schemes, has fewer extendable constellation points and more corresponding extended constellation points, resulting in better BER performance with almost the same PAPR reduction. Computer simulations are given to demonstrate the effectiveness of the proposed scheme.
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VTC Spring - An Improved Constellation Extension Scheme for PAPR Reduction in OFDM Systems
2011 IEEE 73rd Vehicular Technology Conference (VTC Spring), 2011Co-Authors: Chin-liang Wang, Shun-sheng Wang, Yi-ching HuangAbstract:A number of peak-to-average power ratio (PAPR) reduction techniques have been proposed for orthogonal frequency division multiplexing (OFDM) systems; however, most of them require Transmitting Side information and thus reduce the bandwidth efficiency. The existing constellation extension (CE) schemes do not need to transmit Side information. In this paper, we propose an improved CE scheme for PAPR reduction of OFDM signals with 16-QAM modulation. The proposed CE scheme has four extendable constellation points, the four corners in the 16-QAM constellation, and each extendable constellation point has two possible extended constellation points. The proposed CE scheme, when compared with previous related CE schemes, has fewer extendable constellation points and more corresponding extended constellation points, resulting in better BER performance with almost the same PAPR reduction. Computer simulations are given to demonstrate the effectiveness of the proposed scheme.
Bo Zhang - One of the best experts on this subject based on the ideXlab platform.
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output voltage identification based on Transmitting Side information for implantable wireless power transfer system
IEEE Access, 2019Co-Authors: Xiangtian Meng, Dongyuan Qiu, Manhao Lin, Sai Chun Tang, Bo ZhangAbstract:Wireless power transfer (WPT) offers a promising solution to power implantable medical devices (IMDs). Due to the variations of mutual inductance and load, the output voltage of the implantable WPT system is easily unstable. To maintain a constant voltage for IMDs’ operation, a novel method to identify the output voltage of the WPT system without any direct measurement on the receiving Side is presented in this paper, where only the input voltage and current need to be measured. First, the output voltage identification of the WPT system is applied to the classic series–parallel compensation network. Next, an improved WPT system with S-LCL compensation network is proposed, which has the advantage that the output voltage identification is independent of mutual inductance and load resistance. Moreover, the characteristic analysis of the proposed WPT system is carried out, which proves its performance of high transfer efficiency. Finally, the WPT prototype with the S-LCL compensation network is built and tested. The experimental results are provided to further verify the correctness of theoretical analysis.
Yi Tang - One of the best experts on this subject based on the ideXlab platform.
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pulse density modulation for maximum efficiency point tracking of wireless power transfer systems
IEEE Transactions on Power Electronics, 2018Co-Authors: Hongchang Li, Jingyang Fang, Shuxin Chen, Kangping Wang, Yi TangAbstract:Maximum efficiency point tracking (MEPT) control has been adopted in state-of-the-art wireless power transfer (WPT) systems to meet the power demands with the highest efficiency against coupling and load variations. Conventional MEPT implementations use dc/dc converters on both Transmitting and receiving Sides to regulate the output voltage and maximize the system efficiency at the expense of increased overall complexity and power losses on the dc/dc converters. Other implementations use phase-shift control or on–off control of the Transmitting Side inverter and the receiving Side active rectifier instead of dc/dc converters but cause new problems, e.g., hard switching, low average efficiency, and large dc voltage ripples. This paper proposes a pulse density modulation (PDM) based implementation for MEPT to eliminate all the mentioned disadvantages of existing implementations. Delta-sigma modulators are used as an example to realize the PDM. A dual-Side soft switching technique is proposed for the PDM. The ripple factor of the output voltage with PDM is derived. A 50 W WPT system is built to validate the proposed method. The system efficiency is maintained higher than 70% for various load resistances when the power transfer distance is 0.5 m, which is 1.67 times the diameter of the coils.
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pulse density modulation for maximum efficiency point tracking of wireless power transfer systems
IEEE Transactions on Power Electronics, 2018Co-Authors: Jingyang Fang, Shuxin Chen, Kangping Wang, Yi TangAbstract:Maximum efficiency point tracking (MEPT) control has been adopted in state-of-the-art wireless power transfer (WPT) systems to meet the power demands with the highest efficiency against coupling and load variations. Conventional MEPT implementations use dc/dc converters on both Transmitting and receiving Sides to regulate the output voltage and maximize the system efficiency at the expense of increased overall complexity and power losses on the dc/dc converters. Other implementations use phase-shift control or on–off control of the Transmitting Side inverter and the receiving Side active rectifier instead of dc/dc converters but cause new problems, e.g., hard switching, low average efficiency, and large dc voltage ripples. This paper proposes a pulse density modulation (PDM) based implementation for MEPT to eliminate all the mentioned disadvantages of existing implementations. Delta-sigma modulators are used as an example to realize the PDM. A dual-Side soft switching technique is proposed for the PDM. The ripple factor of the output voltage with PDM is derived. A 50 W WPT system is built to validate the proposed method. The system efficiency is maintained higher than 70% for various load resistances when the power transfer distance is 0.5 m, which is 1.67 times the diameter of the coils.
