Results 271 to 280 of about 12,015,384 (327)

Negative-Sequence Directional Ground Relaying

Transactions of the American Institute of Electrical Engineers. Part III: Power Apparatus and Systems, 1962
The principles, problems, and solutions in applying negative sequence for directional ground relaying in 3-phase power systems are given in detail. Two general application areas are covered: (1) where system economics do not permit the necessary equipment for zero-sequence polarization and (2) for mutual induction on parallel lines.
W. A. Elmore, J. L. Blackburn
openaire   +1 more source

Digital Measurement of Negative Phase Sequence Voltages

IEEE Transactions on Power Apparatus and Systems, 1984
A digital method of measuring negative phase sequence voltages using a computer system is described. The accuracy of such a system is discussed and the results of measurements made during site tests are given. An approximate method of separating negative phase sequence voltages inherent in the supply and those caused by the load is shown.
P. H. Buxton, R. E. Morrison
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Interturn Fault Severity Monitoring in Symmetrical Six-Phase PMSMs Using Subspace Negative-Sequence High-Frequency Current Residuals

IEEE transactions on power electronics
This article proposes a fault severity monitoring method for interturn short-circuit fault (ISCF) based on the xy subspace negative-sequence high-frequency (HF) current residuals in symmetrical six-phase permanent magnet synchronous machines.
Huidong Wang, Jian-Fen Hu, Yong Li
semanticscholar   +1 more source

Negative-Sequence Second-Order Circulating Current Injection for Hybrid MMC Under Over-Modulation Conditions

IEEE Journal of Emerging and Selected Topics in Power Electronics, 2020
Due to the presence of full-bridge submodules (FBSMs), hybrid modular multilevel converters (HMMCs) consisting of FBSMs and half-bridge submodules (HBSMs) can work under the over-modulation conditions, which means that half of the dc voltage is less than
Pengfei Hu, R. Teodorescu, J. Guerrero
semanticscholar   +1 more source

Negative obstacle detection from image sequences

SPIE Proceedings, 2011
Negative obstacle detection has been a challenging topic. In the previous researches, the distance that negative obstacles can be detected is so near that vehicles have to travel at a very low speed. In this paper, a negative obstacle detection algorithm from image sequences is proposed.
Tingbo Hu, Yiming Nie, Tao Wu, Hangen He
openaire   +1 more source

A Novel Suppression Method for Input Current Zero-Crossing Distortion of the Vienna Rectifier Based on Negative-Sequence Current Regulation Under the Unbalanced Grid

IEEE Journal of Emerging and Selected Topics in Power Electronics
Vienna rectifier with simple structure and high power density is widely used in industrial applications such as aviation power supplies and electric vehicle charging systems. The conventional control strategy is not effective in suppressing input current
Zhaocheng Shi, Yiwen Wu, Xiang Gao, Heqiang Zhang, Junjie Fang, Huimin Cheng, Lili Dong   +6 more
semanticscholar   +1 more source

Calculation of negative-sequence losses and negative-sequence resistance of turbogenerators

IEEE Transactions on Power Apparatus and Systems, 1975
The negative-sequence losses and their calculation are of great significance for large turbogenerators having high utilization factors. A generalized method for the determination of negative-sequence losses and negative-sequence resistance is given. With the help of equivalent circuits, accounting for all the given constructional particularities of the
openaire   +1 more source

Negative Sequence Current Regulation Based Power Control Strategy for Vienna Rectifier Under Unbalanced Grid Voltage Dips

IEEE transactions on industrial electronics (1982. Print)
When Vienna rectifier operates at unbalanced grid voltage dips, the conventional power control strategy suffers from the active power reduction and the input current distortion.
Zhijian Zhang, Guoqiang Zhang, Wenlong Liu, Bin Hu, Jiarui Wang, Gaolin Wang, Dianguo Xu   +6 more
semanticscholar   +1 more source

A review of negative sequence current

2010 63rd Annual Conference for Protective Relay Engineers, 2010
Sequence component analysis plays an essential role in analyzing power system faults and explaining some power system phenomena. It is very well known that negative sequence current could cause rotor damage, and that damage is highly detrimental to rotating machines such as motors and generators.
John Wang, Randy Hamilton
openaire   +1 more source

Extension of Negative-Sequence Current Compensation Range Based on Negative- and Zero-Sequence Voltage Injection for Hybrid Cascaded STATCOM

IEEE transactions on industrial electronics (1982. Print)
Negative-sequence voltage (NSV) injection is an effective cluster balancing control for CHB STATCOM, which has a higher capability in eliminating unbalanced active powers than zero sequence voltage (ZSV) injection.
Daorong Lu, M. Wei, Tianhong Wu, Haibing Hu   +3 more
semanticscholar   +1 more source