The Experts below are selected from a list of 53076 Experts worldwide ranked by ideXlab platform
Zhao Long - One of the best experts on this subject based on the ideXlab platform.
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Research of Impact of Wind on Radio Interference Due to ±800kV DC Transmission Line
Power system technology, 2012Co-Authors: Zhao LongAbstract:The Radio Interference caused by HVDC power transmission lines is not only related to the voltage applied to the conductors and the arrangement of conductors,but also to the weather conditions,especially the wind greatly impacts on the Radio Interference.The mechanism of Radio Interference caused by HVDC power transmission line is analyzed.It is the first time in China to perform long-term testing and measurement of Radio Interference by UHVDC test line with actual sizes applied in UHVDC power transmission line and the Radio Interference characteristics of UHVDC power transmission line is researched,thus the law by which the wind impacts on Radio Interference is obtained.The strength of Radio Interference caused by DC corona resulted from UHVDC power transmission line becomes more intensive with the increase of wind speed when the wind blows from the negative polar conductor of UHVDC transmission line to its positive polar conductor.
Kazuya Tsukamoto - One of the best experts on this subject based on the ideXlab platform.
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CloudNet - Elastic Channel Utilization Against External Radio Interference on SDN-Enabled Multi-Radio Wireless Backhaul Networks
2018 IEEE 7th International Conference on Cloud Networking (CloudNet), 2018Co-Authors: Yuzo Taenaka, Kazuya TsukamotoAbstract:This paper tries to avoid a Radio Interference while effectively utilizing the resource of interfered channel on SDN-based wireless backhaul networks (WBNs). The densification of small cells on wireless networks is required to handle a lot of traffic for the cloud-based ICT services but inevitably needs a WBN to provide network connectivity at every cell. Since most traffic is delayed or dropped once a WBN suffers from a Radio Interference coming from outside of the WBN, it is general to avoid using the interfered channel or switch a route spatially. Although such countermeasures are effective to avoid an external Radio Interference, it could be less effective in terms of resource utilization because the interfered channel may still remain resource. From this perspective, we propose a method that estimates the residual resource of interfered channel and uses it as much as possible while avoiding the effect arising from the Radio Interference. Specifically, our proposed method uses the information about incoming/outgoing traffic to estimate the residual resource and migrate a part of traffic to another channel until the amount of incoming traffic and that of outgoing packets are balanced (i.e., the channel is not a bottleneck anymore). The experimental results showed that our method is able to estimate the residual resource of interfered channel and effectively use it even under external Radio Interference.
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a Radio Interference aware dynamic channel utilization method on software defined wmn
2015 10th International Conference on P2P Parallel Grid Cloud and Internet Computing (3PGCIC), 2015Co-Authors: Yuzo Taenaka, Kazuya TsukamotoAbstract:This paper proposes a dynamic channel utilization method enabling to consider the effect of Radio Interference on software defined multi-channel wireless mesh network (SD-WMN). In our SD-WMN, a set of APs, each of which uses a single and different channel, is connected by Ethernet each other and thus constructs a VAP handling multiple channels. The OpenFlow technology, which enables us to programmably control traffic, is employed to effectively utilize multiple channels in SD-WMN for improvement of the network capacity. Although we already proposed several channel utilization methods, either channel may be saturated even if other channels still have residual capacity. This is because the Radio Interference inevitably occurs inside WMN due to multi-hop transmission nature. Thus, to avoid the saturation of either channel while utilizing all channels effectively, we propose a new method that can consider the effect of Radio Interference inside WMN. In the method, all interfered APs can be reliably detected and the network load is balanced in conjunction with the interfered APs by considering the Radio Interference. From the experimental results, the proposed method can avoid the saturation of either channel successfully, thereby increasing the network capacity drastically.
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3PGCIC - A Radio Interference Aware Dynamic Channel Utilization Method on Software Defined WMN
2015 10th International Conference on P2P Parallel Grid Cloud and Internet Computing (3PGCIC), 2015Co-Authors: Yuzo Taenaka, Kazuya TsukamotoAbstract:This paper proposes a dynamic channel utilization method enabling to consider the effect of Radio Interference on software defined multi-channel wireless mesh network (SD-WMN). In our SD-WMN, a set of APs, each of which uses a single and different channel, is connected by Ethernet each other and thus constructs a VAP handling multiple channels. The OpenFlow technology, which enables us to programmably control traffic, is employed to effectively utilize multiple channels in SD-WMN for improvement of the network capacity. Although we already proposed several channel utilization methods, either channel may be saturated even if other channels still have residual capacity. This is because the Radio Interference inevitably occurs inside WMN due to multi-hop transmission nature. Thus, to avoid the saturation of either channel while utilizing all channels effectively, we propose a new method that can consider the effect of Radio Interference inside WMN. In the method, all interfered APs can be reliably detected and the network load is balanced in conjunction with the interfered APs by considering the Radio Interference. From the experimental results, the proposed method can avoid the saturation of either channel successfully, thereby increasing the network capacity drastically.
Aydogan Ozdemir - One of the best experts on this subject based on the ideXlab platform.
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Far-field prediction for Radio-Interference produced by fundamental frequency of a DC Corona discharge at a Rod-Plane configuration
IEEE Electromagnetic Compatibility Magazine, 2020Co-Authors: Julio C. Salazar-hernandez, Fermin P. Espino-cortes, R. Linares Y Miranda, Aydogan OzdemirAbstract:In this article an experimental methodology for predicting far-field Radio-Interference from the pulse conducted of positive corona current measured in a rod-plane configuration is presented. From the pulsed conducted corona current, the fundamental frequency is determined. The source of the corona discharge (rod-plane structure) is considered as a small dipole antenna of length equal to the gap of the rod-plane. Applying the basic propagation expressions and the far-field expression for a small dipole antenna, the Radio-Interference is predicted. The Radio-Interference (electric field) is measured by a loop antenna according to CISPR-16 standard. One of main result in this work is the determination of the fundamental frequency of the corona discharge for different gaps of a rod-plane configuration frequency where the energy is concentrated. Using this parameter, the far-field electric is predicted. The emissions radiated measurements at a distance of 4 m are above of the EMC standard limits.
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Optimization of Radio Interference Levels for 500 and 600 kV Bipolar HVDC Transmission Lines
Energies, 2019Co-Authors: Carlos Tejada-martinez, Fermin P. Espino-cortes, Suat Ilhan, Aydogan OzdemirAbstract:In this work, a method to compute the Radio Interference (RI) lateral profiles generated by corona discharge in high voltage direct current (HVDC) transmission lines is presented. The method is based on a transmission line model that considers the skin effect, through the concept of complex penetration depth, in the conductors and in the ground plane. The attenuation constants are determined from the line parameters and the bipolar system is decoupled by using modal decomposition theory. As application cases, ±500 and ±600 kV bipolar transmission lines were analyzed. Afterwards, parametric sweeps of five variables that affect the RI levels are presented. Both the RI and the maximum electric field were calculated as a function of sub-conductor radius, bundle spacing, and the number of sub-conductors in the bundle. Additionally, the RI levels were also calculated as a function of the soil resistivity, and the RIV (Radio Interference voltage) frequency. Following this, vector optimization was applied to minimize the RI levels produced by the HVDC lines and differences between the designs with nominal and optimal values are discussed.
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Minimization of Radio Interference Levels in a Hybrid Transmission Line
2019 IEEE Milan PowerTech, 2019Co-Authors: Carlos Tejada-martinez, Fermin P. Espino-cortes, Aydogan Ozdemir, Suat IlhanAbstract:In this paper, the Radio Interference (RI) lateral profiles produced by corona discharges in a hybrid transmission line are computed. The applied method is based on the calculation of the conductor surface voltage gradients considering the interaction between AC and DC circuits. Then, the Radio Interference levels produced by each phase/pole conductor are calculated by means of empirical formulas presented in previous works for two weather conditions: heavy rain and fair weather. Two hybrid line configurations are compared in order to determine which one produces the lowest RI levels. After that, vector optimization is applied in order to minimize the RI levels produced by the best hybrid line configuration, considering three independent variables: subconductors radius, bundle spacing, and the number of subconductors in the bundle. Finally, RI lateral profiles with both nominal and optimal values are compared.
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Optimization of Corona Radio Interference Levels in HVDC Transmission Lines
2018 IEEE International Conference on High Voltage Engineering and Application (ICHVE), 2018Co-Authors: Carlos Tejada-martinez, Fermin P. Espino-cortes, Suat Ilhan, Aydogan OzdemirAbstract:This article presents the computation of Radio Interference (RI) lateral profiles produced by corona discharge in a bipolar HVDC transmission line of ±500 kV. The method used to compute the RI levels considers a transmission line model that takes into consideration the skin effect by using the concept of complex penetration depth in the pole conductors and in the ground plane. Also, the attenuation constants are calculated from the line parameters and the bipolar system is decoupled by using modal decomposition theory. Furthermore, the influence of four variables in both RI levels and the maximum bundle electric field is analyzed: sub-conductors radius, bundle spacing, the number of sub-conductors in the bundle and the soil resistivity. Afterwards, vector optimization is applied in order to minimize the RI levels produced by the bipolar line. Finally, RI lateral profiles with both nominal and optimal values are compared.
Yuzo Taenaka - One of the best experts on this subject based on the ideXlab platform.
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CloudNet - Elastic Channel Utilization Against External Radio Interference on SDN-Enabled Multi-Radio Wireless Backhaul Networks
2018 IEEE 7th International Conference on Cloud Networking (CloudNet), 2018Co-Authors: Yuzo Taenaka, Kazuya TsukamotoAbstract:This paper tries to avoid a Radio Interference while effectively utilizing the resource of interfered channel on SDN-based wireless backhaul networks (WBNs). The densification of small cells on wireless networks is required to handle a lot of traffic for the cloud-based ICT services but inevitably needs a WBN to provide network connectivity at every cell. Since most traffic is delayed or dropped once a WBN suffers from a Radio Interference coming from outside of the WBN, it is general to avoid using the interfered channel or switch a route spatially. Although such countermeasures are effective to avoid an external Radio Interference, it could be less effective in terms of resource utilization because the interfered channel may still remain resource. From this perspective, we propose a method that estimates the residual resource of interfered channel and uses it as much as possible while avoiding the effect arising from the Radio Interference. Specifically, our proposed method uses the information about incoming/outgoing traffic to estimate the residual resource and migrate a part of traffic to another channel until the amount of incoming traffic and that of outgoing packets are balanced (i.e., the channel is not a bottleneck anymore). The experimental results showed that our method is able to estimate the residual resource of interfered channel and effectively use it even under external Radio Interference.
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a Radio Interference aware dynamic channel utilization method on software defined wmn
2015 10th International Conference on P2P Parallel Grid Cloud and Internet Computing (3PGCIC), 2015Co-Authors: Yuzo Taenaka, Kazuya TsukamotoAbstract:This paper proposes a dynamic channel utilization method enabling to consider the effect of Radio Interference on software defined multi-channel wireless mesh network (SD-WMN). In our SD-WMN, a set of APs, each of which uses a single and different channel, is connected by Ethernet each other and thus constructs a VAP handling multiple channels. The OpenFlow technology, which enables us to programmably control traffic, is employed to effectively utilize multiple channels in SD-WMN for improvement of the network capacity. Although we already proposed several channel utilization methods, either channel may be saturated even if other channels still have residual capacity. This is because the Radio Interference inevitably occurs inside WMN due to multi-hop transmission nature. Thus, to avoid the saturation of either channel while utilizing all channels effectively, we propose a new method that can consider the effect of Radio Interference inside WMN. In the method, all interfered APs can be reliably detected and the network load is balanced in conjunction with the interfered APs by considering the Radio Interference. From the experimental results, the proposed method can avoid the saturation of either channel successfully, thereby increasing the network capacity drastically.
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3PGCIC - A Radio Interference Aware Dynamic Channel Utilization Method on Software Defined WMN
2015 10th International Conference on P2P Parallel Grid Cloud and Internet Computing (3PGCIC), 2015Co-Authors: Yuzo Taenaka, Kazuya TsukamotoAbstract:This paper proposes a dynamic channel utilization method enabling to consider the effect of Radio Interference on software defined multi-channel wireless mesh network (SD-WMN). In our SD-WMN, a set of APs, each of which uses a single and different channel, is connected by Ethernet each other and thus constructs a VAP handling multiple channels. The OpenFlow technology, which enables us to programmably control traffic, is employed to effectively utilize multiple channels in SD-WMN for improvement of the network capacity. Although we already proposed several channel utilization methods, either channel may be saturated even if other channels still have residual capacity. This is because the Radio Interference inevitably occurs inside WMN due to multi-hop transmission nature. Thus, to avoid the saturation of either channel while utilizing all channels effectively, we propose a new method that can consider the effect of Radio Interference inside WMN. In the method, all interfered APs can be reliably detected and the network load is balanced in conjunction with the interfered APs by considering the Radio Interference. From the experimental results, the proposed method can avoid the saturation of either channel successfully, thereby increasing the network capacity drastically.
He Jin-liang - One of the best experts on this subject based on the ideXlab platform.
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Effect of Altitude on Radio Interference Based on Corona Test Cage
High Voltage Engineering, 2009Co-Authors: He Jin-liangAbstract:As an important index of electromagnetic environment, Radio Interference due to corona is much higher in high altitude area than on ground. For proper conductor selection, it is necessary to study the corona effect of conductor in high altitude area. Thereby, a mobile corona test cage was applied to research the influence of altitude changes on AC corona Radio Interference of conductor. The effects of conductor surface gradients and altitude on Radio Interference were analyzed in detail. Based on linear correction relation, a correction coefficient of 3.13 dB/1000 m was obtained which was well in agreement with the foreign coefficient 3.3 dB/1000 m. The test results show that AC corona Radio Interference of conductor is nonlinearly varied with altitude. The higher the altitude is, the smaller the effect of altitude changes on AC corona Radio Interference will be. An emprical expression between altitude correction coefficients with the altitudes is presented. Finally, an altitude correction method of RI is put forward.
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Calculation Methods of Radio Interference Caused by AC Transmission Lines
Power system technology, 2008Co-Authors: He Jin-liangAbstract:More and more attentions are paid to the Radio Interference caused by AC high voltage transmission lines. Based on the parameters of actual transmission lines and measured data, the authors compare the discrepancies among frequently used empirical formulae for Radio Interference. On the basis of introducing the basic principle of Radio Interference calculation by excitation function method, the discrepancies among various excitation functions are compared. The standard of limit values of Radio Interference and the problems in engineering practice are discussed, the possible sources of the errors between calculation results and measured results are analyzed and it is pointed out that the soil resistivity, surface electrical field strength of conductor and so on greatly affect calculation results.
