The Experts below are selected from a list of 83775 Experts worldwide ranked by ideXlab platform
Ahmed M. Massoud - One of the best experts on this subject based on the ideXlab platform.
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an improved fault tolerant five phase induction machine using a combined star pentagon single layer stator winding connection
IEEE Transactions on Industrial Electronics, 2016Co-Authors: Ayman S Abdelkhalik, Mohamed A. Elgenedy, Shehab Ahmed, Ahmed M. MassoudAbstract:One of the main merits offered by multiphase machines is their high fault-tolerant capability. Literature has demonstrated that the performance of multiphase induction machines under fault conditions is affected by the employed stator winding connection. In open-loop controlled five-phase machines, the star connection is favorable under healthy conditions while the pentagon connection is favorable and yields a lower derating factor under the open phase condition. In this paper, a new combined star/pentagon single layer winding layout that combines the advantages of both star and pentagon connections is proposed for a five-phase induction machine. Although the proposed winding is intrinsically an asymmetrical ten-phase machine, the proposed connection allows for only five-phase terminals. Moreover, the proposed winding not only yields better Flux distribution compared to a conventional single layer winding, but also provides a complete cancellation of the third-order harmonic Flux Component caused by the induced third sequence currents due to the saturation effect and/or under unbalanced operation. Hence, the machine losses are decreased, which improves the overall machine efficiency. For the healthy case, the machine is similar to a conventional star connected five-phase machine. However, with one phase open, the proposed connection results in a lower derating factor compared to conventional connections for both open-loop and optimal current control techniques. A 1-kW prototype machine is used for experimental verification.
Ayman S Abdelkhalik - One of the best experts on this subject based on the ideXlab platform.
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an improved fault tolerant five phase induction machine using a combined star pentagon single layer stator winding connection
IEEE Transactions on Industrial Electronics, 2016Co-Authors: Ayman S Abdelkhalik, Mohamed A. Elgenedy, Shehab Ahmed, Ahmed M. MassoudAbstract:One of the main merits offered by multiphase machines is their high fault-tolerant capability. Literature has demonstrated that the performance of multiphase induction machines under fault conditions is affected by the employed stator winding connection. In open-loop controlled five-phase machines, the star connection is favorable under healthy conditions while the pentagon connection is favorable and yields a lower derating factor under the open phase condition. In this paper, a new combined star/pentagon single layer winding layout that combines the advantages of both star and pentagon connections is proposed for a five-phase induction machine. Although the proposed winding is intrinsically an asymmetrical ten-phase machine, the proposed connection allows for only five-phase terminals. Moreover, the proposed winding not only yields better Flux distribution compared to a conventional single layer winding, but also provides a complete cancellation of the third-order harmonic Flux Component caused by the induced third sequence currents due to the saturation effect and/or under unbalanced operation. Hence, the machine losses are decreased, which improves the overall machine efficiency. For the healthy case, the machine is similar to a conventional star connected five-phase machine. However, with one phase open, the proposed connection results in a lower derating factor compared to conventional connections for both open-loop and optimal current control techniques. A 1-kW prototype machine is used for experimental verification.
I N Myagkova - One of the best experts on this subject based on the ideXlab platform.
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relationship of type iii radio bursts with quasi periodic pulsations in a solar flare
Solar Physics, 2016Co-Authors: Elena G Kupriyanova, L K Kashapova, Hamish A S Reid, I N MyagkovaAbstract:We studied a solar flare with pronounced quasi-periodic pulsations detected in the microwave, X-ray, and radio bands. We used correlation, Fourier, and wavelet analyses methods to examine the temporal fine structures and relationships between the time profiles in each wave band. We found that the time profiles of the microwaves, hard X-rays, and type III radio bursts vary quasi-periodically with a common period of 40 – 50 s. The average amplitude of the variations is high, above 30 % of the background Flux level, and reaches 80 % after the flare maximum. We did not find this periodicity in either the thermal X-ray Flux Component or in the source size dynamics. Our findings indicate that the detected periodicity is probably associated with periodic dynamics in the injection of non-thermal electrons, which can be produced by periodic modulation of magnetic reconnection.
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relationship of type iii radio bursts with quasi periodic pulsations in a solar flare
arXiv: Solar and Stellar Astrophysics, 2016Co-Authors: Elena G Kupriyanova, L K Kashapova, Hamish A S Reid, I N MyagkovaAbstract:We studied a solar flare with pronounced quasi-periodic pulsations detected in the microwave, X-ray, and radio bands. We used the methods of correlation, Fourier, and wavelet analyses to examine the temporal fine structures and relationships between the time profiles in each wave band. We found that the time profiles of the microwaves, hard X-rays and type III radio bursts vary quasi-periodically with the common period of 40-50 s. The average amplitude of the variations is high, above 30% of the background Flux level and reaching 80% after the flare maximum. We did not find the periodicity in either the thermal X-ray Flux Component or source size dynamics. Our findings indicate that the detected periodicity is likely to be associated with periodic dynamics in the injection of non-thermal electrons, that can be produced by periodic modulation of magnetic reconnection.
Shehab Ahmed - One of the best experts on this subject based on the ideXlab platform.
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an improved fault tolerant five phase induction machine using a combined star pentagon single layer stator winding connection
IEEE Transactions on Industrial Electronics, 2016Co-Authors: Ayman S Abdelkhalik, Mohamed A. Elgenedy, Shehab Ahmed, Ahmed M. MassoudAbstract:One of the main merits offered by multiphase machines is their high fault-tolerant capability. Literature has demonstrated that the performance of multiphase induction machines under fault conditions is affected by the employed stator winding connection. In open-loop controlled five-phase machines, the star connection is favorable under healthy conditions while the pentagon connection is favorable and yields a lower derating factor under the open phase condition. In this paper, a new combined star/pentagon single layer winding layout that combines the advantages of both star and pentagon connections is proposed for a five-phase induction machine. Although the proposed winding is intrinsically an asymmetrical ten-phase machine, the proposed connection allows for only five-phase terminals. Moreover, the proposed winding not only yields better Flux distribution compared to a conventional single layer winding, but also provides a complete cancellation of the third-order harmonic Flux Component caused by the induced third sequence currents due to the saturation effect and/or under unbalanced operation. Hence, the machine losses are decreased, which improves the overall machine efficiency. For the healthy case, the machine is similar to a conventional star connected five-phase machine. However, with one phase open, the proposed connection results in a lower derating factor compared to conventional connections for both open-loop and optimal current control techniques. A 1-kW prototype machine is used for experimental verification.
Mohamed A. Elgenedy - One of the best experts on this subject based on the ideXlab platform.
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an improved fault tolerant five phase induction machine using a combined star pentagon single layer stator winding connection
IEEE Transactions on Industrial Electronics, 2016Co-Authors: Ayman S Abdelkhalik, Mohamed A. Elgenedy, Shehab Ahmed, Ahmed M. MassoudAbstract:One of the main merits offered by multiphase machines is their high fault-tolerant capability. Literature has demonstrated that the performance of multiphase induction machines under fault conditions is affected by the employed stator winding connection. In open-loop controlled five-phase machines, the star connection is favorable under healthy conditions while the pentagon connection is favorable and yields a lower derating factor under the open phase condition. In this paper, a new combined star/pentagon single layer winding layout that combines the advantages of both star and pentagon connections is proposed for a five-phase induction machine. Although the proposed winding is intrinsically an asymmetrical ten-phase machine, the proposed connection allows for only five-phase terminals. Moreover, the proposed winding not only yields better Flux distribution compared to a conventional single layer winding, but also provides a complete cancellation of the third-order harmonic Flux Component caused by the induced third sequence currents due to the saturation effect and/or under unbalanced operation. Hence, the machine losses are decreased, which improves the overall machine efficiency. For the healthy case, the machine is similar to a conventional star connected five-phase machine. However, with one phase open, the proposed connection results in a lower derating factor compared to conventional connections for both open-loop and optimal current control techniques. A 1-kW prototype machine is used for experimental verification.