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H Toki - One of the best experts on this subject based on the ideXlab platform.

  • theoretical study of lumped parameter circuits and multiconductor transmission lines for time domain analysis of Electromagnetic Noise
    Scientific Reports, 2019
    Co-Authors: Masayuki Abe, H Toki
    Abstract:

    In order to find the origins of Electromagnetic Noise in the time domain, we formulate a system of lumped parameter circuits and multiconductor transmission lines (MTL). We present a discretized approach to treat any lumped parameter circuits and MTL systems, and the boundary conditions between these systems, where the lumped parameter circuits are described by coupled differential equations, and the MTL systems by coupled partial-differential equations. The introduction of the time-domain impedance and the element matrices enables us to perform a time-domain analysis that includes dependent sources and the coupling devices in the framework of the circuit theory. For three-line systems, we are able to calculate the coupling of the normal, common, and antenna modes, and to find out methods to reduce the Noise.

  • multiconductor transmission line theory that includes an antenna process with a lumped parameter circuit
    Journal of the Physical Society of Japan, 2016
    Co-Authors: H Toki, Masayuki Abe
    Abstract:

    Electromagnetic Noise was studied theoretically by developing a multiconductor transmission-line (MTL) theory derived from Maxwell’s equations without any approximations. The MTL theory naturally contains the antenna process, and for the case of three lines it is written in terms of normal, common, and antenna modes. Here we develop a theoretical method to solve the MTL equations by introducing boundary conditions consisting of a lumped-parameter circuit in order to describe the performance of any electric circuit for good performance without Noise. The finite-difference time-domain (FDTD) method is a powerful algorithm to solve time-dependent coupled differential equations for a combined distributed- and lumped-parameter circuit.

  • Electromagnetic Noise in electric circuits ringing and resonance phenomena in the common mode
    AIP Advances, 2014
    Co-Authors: Shuji Kitora, H Toki
    Abstract:

    It is generally believed that Electromagnetic Noise originates from the coupling of electric signals in a circuit with electric signals in surrounding materials in the environment. However, the Noise phenomenon had not been quantified until now. In order to study the phenomenon of Noise, we considered a standard circuit (two transmission lines), to which an additional transmission line was introduced in order to explicitly take into account the effect of conductors in the environment. We performed calculations using a newly developed multiconductor transmission-line theory for the resulting three-line circuit in order to determine the magnitude of the coupling between the circuit and the conductors in the environment under various conditions. We observed ringing and resonance phenomena in the common mode, which influenced the performance of the normal mode as Electromagnetic Noise. Our findings were confirmed by recent experiments in which conductor lines were arranged in various ways using a printed circ...

  • new circuit theory of multiconductor transmission lines resulting from a new practice of Noise reduction
    Proceedings of the Japan Academy. Series B Physical and Biological Sciences, 2014
    Co-Authors: H Toki, Kenji Sato
    Abstract:

    In modern life, we are surrounded by and filled with Electromagnetic Noise caused by the dominant use of energy in the form of electricity. This situation is brought about by the fact that the Noise is not understood theoretically. A new practice of Noise reduction was introduced for the construction of Heavy Ion Medical Accelerator in Chiba (HIMAC). The key concept is a symmetric three-line circuit that arranges power supplies, Noise filters and magnets around a third central ground line. A continuous theoretical effort forced us to find a new circuit theory involving a multiconductor transmission-line system starting from Maxwell's equations without any approximation. We discuss the essence of all of these experimental and theoretical developments with the hope to remove unnecessary Electromagnetic Noise not only from power supplies, but also from all electric devices. The newly derived circuit theory of multiconductor transmission lines is universal, and establishes the validity of the practice of Noise reduction.

  • three conductor transmission line theory and origin of Electromagnetic radiation and Noise
    Journal of the Physical Society of Japan, 2009
    Co-Authors: H Toki, Kenji Sato
    Abstract:

    We construct a new multiconductor transmission-line theory with coefficients of potential and inductance. We provide coupled differential equations for potential and electric current with coefficients that are given by geometrical configurations of a transmission-line system. We provide a general solution to coupled differential equations explicitly for three-conductor transmission-lines. We derive coupled differential equations for the normal and common modes of lines 1 and 2, where common-mode current goes through line 3. The common mode acts as an antenna for radiating Electromagnetic waves and any Electromagnetic devices and conductors placed around the major conductor transmission-lines (lines 1 and 2) act as receivers of Electromagnetic waves. This is the source of Electromagnetic Noise in the circumstance around the transmission-line system. The transmission-line system receives Noise from the circumstance through the common mode.

Kenji Sato - One of the best experts on this subject based on the ideXlab platform.

  • new circuit theory of multiconductor transmission lines resulting from a new practice of Noise reduction
    Proceedings of the Japan Academy. Series B Physical and Biological Sciences, 2014
    Co-Authors: H Toki, Kenji Sato
    Abstract:

    In modern life, we are surrounded by and filled with Electromagnetic Noise caused by the dominant use of energy in the form of electricity. This situation is brought about by the fact that the Noise is not understood theoretically. A new practice of Noise reduction was introduced for the construction of Heavy Ion Medical Accelerator in Chiba (HIMAC). The key concept is a symmetric three-line circuit that arranges power supplies, Noise filters and magnets around a third central ground line. A continuous theoretical effort forced us to find a new circuit theory involving a multiconductor transmission-line system starting from Maxwell's equations without any approximation. We discuss the essence of all of these experimental and theoretical developments with the hope to remove unnecessary Electromagnetic Noise not only from power supplies, but also from all electric devices. The newly derived circuit theory of multiconductor transmission lines is universal, and establishes the validity of the practice of Noise reduction.

  • three conductor transmission line theory and origin of Electromagnetic radiation and Noise
    Journal of the Physical Society of Japan, 2009
    Co-Authors: H Toki, Kenji Sato
    Abstract:

    We construct a new multiconductor transmission-line theory with coefficients of potential and inductance. We provide coupled differential equations for potential and electric current with coefficients that are given by geometrical configurations of a transmission-line system. We provide a general solution to coupled differential equations explicitly for three-conductor transmission-lines. We derive coupled differential equations for the normal and common modes of lines 1 and 2, where common-mode current goes through line 3. The common mode acts as an antenna for radiating Electromagnetic waves and any Electromagnetic devices and conductors placed around the major conductor transmission-lines (lines 1 and 2) act as receivers of Electromagnetic waves. This is the source of Electromagnetic Noise in the circumstance around the transmission-line system. The transmission-line system receives Noise from the circumstance through the common mode.

Masayuki Abe - One of the best experts on this subject based on the ideXlab platform.

  • theoretical study of lumped parameter circuits and multiconductor transmission lines for time domain analysis of Electromagnetic Noise
    Scientific Reports, 2019
    Co-Authors: Masayuki Abe, H Toki
    Abstract:

    In order to find the origins of Electromagnetic Noise in the time domain, we formulate a system of lumped parameter circuits and multiconductor transmission lines (MTL). We present a discretized approach to treat any lumped parameter circuits and MTL systems, and the boundary conditions between these systems, where the lumped parameter circuits are described by coupled differential equations, and the MTL systems by coupled partial-differential equations. The introduction of the time-domain impedance and the element matrices enables us to perform a time-domain analysis that includes dependent sources and the coupling devices in the framework of the circuit theory. For three-line systems, we are able to calculate the coupling of the normal, common, and antenna modes, and to find out methods to reduce the Noise.

  • multiconductor transmission line theory that includes an antenna process with a lumped parameter circuit
    Journal of the Physical Society of Japan, 2016
    Co-Authors: H Toki, Masayuki Abe
    Abstract:

    Electromagnetic Noise was studied theoretically by developing a multiconductor transmission-line (MTL) theory derived from Maxwell’s equations without any approximations. The MTL theory naturally contains the antenna process, and for the case of three lines it is written in terms of normal, common, and antenna modes. Here we develop a theoretical method to solve the MTL equations by introducing boundary conditions consisting of a lumped-parameter circuit in order to describe the performance of any electric circuit for good performance without Noise. The finite-difference time-domain (FDTD) method is a powerful algorithm to solve time-dependent coupled differential equations for a combined distributed- and lumped-parameter circuit.

Andrzej M Trzynadlowski - One of the best experts on this subject based on the ideXlab platform.

  • shaping the Noise spectrum in power electronic converters
    IEEE Transactions on Industrial Electronics, 2011
    Co-Authors: R L Kirlin, C Lascu, Andrzej M Trzynadlowski
    Abstract:

    The operation of switch-mode converters results in Electromagnetic Noise propagating throughout the power electronic system. Pulsewidth modulation (PWM) strategies with fixed switching frequency generate harmonics in the spectra of converter voltages and currents. Random PWM techniques allow the elimination of the harmonics, resulting in a continuous spectrum of Noise, i.e., a spectrum retaining all frequency components. As a next step in advanced spectral shaping, a method presented in this paper produces spectral nulls at selected frequencies. This allows the carving of communication channels in the Noise and the removal of spectral power at frequencies potentially harmful for the system. The theoretical analysis, computer simulations, implementation details, and experimental results are presented.

  • experimental investigation of a naval propulsion drive model with the pwm based attenuation of the acoustic and Electromagnetic Noise
    IEEE Transactions on Industrial Electronics, 2006
    Co-Authors: K Borisov, T E Calvert, J A Kleppe, E Martin, Andrzej M Trzynadlowski
    Abstract:

    An extensive experimental investigation of a 40-hp ac drive was conducted with the focus on mitigation of the acoustic and Electromagnetic Noise, and vibration, by means of random pulsewidth modulation (RPWM) employed in the drive's inverter. The drive was a laboratory model of an electric propulsion system for naval vessels, particularly electric submarines, in which the Noise mitigation is crucial for survivability. Three PWM methods were compared: 1) the classic deterministic PWM, characterized by a constant switching period equal to the sampling period of the digital modulator; 2) the known RPWM technique, referred to as RPWM I, in which the switching and sampling periods are varied simultaneously in a random manner; and 3) a novel RPWM method, referred to as RPWM II, with a constant sampling period and the switching periods randomly varied around an average value equal to the sampling period. The experimental results have confirmed the mitigating properties of RPWM with respect to the acoustic and Electromagnetic Noise, and vibration. Because of the fixed sampling frequency, the RPWM II technique is technically more convenient than the classic RPWM I method and only marginally less effective in flattening the peaks of Noise spectra. Importantly, conclusions drawn from the described study are valid for ac drives in general.

  • a novel random pwm technique with low computational overhead and constant sampling frequency for high volume low cost applications
    IEEE Transactions on Power Electronics, 2005
    Co-Authors: Andrzej M Trzynadlowski, K Borisov, Ling Qin
    Abstract:

    A novel random pulse-width modulation (PWM) technique for three-phase voltage-source inverters, characterized by low computational overhead, a variable switching frequency, and a constant sampling frequency, is presented. The technique is based on two strategies: 1) the so-called arithmetic PWM (APWM), which yields the same switching patterns as the classic space-vector modulation, but with minimal computational effort and 2) randomization of switching periods by varying the delay of switching cycles with respect to corresponding sampling cycles. Simplicity of the technique, named a variable-delay random PWM (VDRPWM) method, allows its implementation in cheap, low-end processors. It makes the VDRPWM the best choice for high-volume, low-cost applications, such as domestic and automotive ac drives and UPSs. The random aspect of the technique has a mitigating effect on the acoustic and Electromagnetic Noise emitted by the supplied system. This feature has been confirmed by experiments with a 40-hp induction motor drive.

Kazuo Amano - One of the best experts on this subject based on the ideXlab platform.

  • development of fault point locating system for underground transmission lines using optical fiber current sensors
    Electrical Engineering in Japan, 2012
    Co-Authors: Kiyoshi Kurosawa, Reishi Kondo, Shinsuke Nasukawa, Tatsushi Yamaguchi, Kazuo Amano
    Abstract:

    Fault point locating systems based on surge current detection have recently been used for fast recovery of underground transmission lines from faults. Electromagnetic induction type sensors have mainly been used for the detection of surge current. However, they are susceptible to Electromagnetic Noise which causes unstable system operation. To solve this problem, Tokyo Electric Power Co., Toko Electric Corporation, and Fujikura Ltd. jointly developed a new system using optical fiber current sensors. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 178(1): 21–28, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.20981

  • development of fault point locating system for underground transmission lines using optical fiber current sensors
    Ieej Transactions on Power and Energy, 2008
    Co-Authors: Kiyoshi Kurosawa, Reishi Kondo, Shinsuke Nasukawa, Tatsushi Yamaguchi, Kazuo Amano
    Abstract:

    Fault point locating systems based on surge current detection have recently been used for fast recovery of underground transmission line from the fault. Electromagnetic induction type sensors have mainly been used for detection of the surge current. However they are susceptible to Electromagnetic Noise which causes unstable system operation. To solve this problem, Tokyo Electric Power Co., Toko Electric Corporation and Fujikura Ltd., by a joint research, have developed a new system that applies optical fiber current sensors.