Results 261 to 270 of about 266,614 (289)
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Measurement of zero-sequence voltage without galvanic coupling to the network
Russian Electrical Engineering, 2011The possibility of the contactless extraction of the zero-sequence voltage for earth fault protection and control devices using the phenomenon of electrostatic induction is considered.
N. Sh. Shayakberov, F. S. Mingazov
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Zero Sequence Voltage Phasor Positioning under Balanced Three-Phase Supply
2019 International Ural Conference on Electrical Power Engineering (UralCon), 2019Based on the representations in barycentric coordinates on a balanced supply line-to-line voltages triangle the resulting complex-plane static phasors of the zero sequence voltage and of the related unbalance factor are obtained for the balanced mode of the three-phase supplying. It is supposed that the voltages and currents are sinusoidal.
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IEEE Transactions on Industrial Electronics, 2017
A zero-sequence circulating current (ZSCC) is typically generated among the multiparallel converters that share the common dc link and ac side without isolated transformers under the space vector modulation (SVM), due to the injected third-order zero-sequence voltage (ZSV).
Rongwu Zhu +3 more
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A zero-sequence circulating current (ZSCC) is typically generated among the multiparallel converters that share the common dc link and ac side without isolated transformers under the space vector modulation (SVM), due to the injected third-order zero-sequence voltage (ZSV).
Rongwu Zhu +3 more
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On-Site Low Voltage Determination of Zero-Sequence Impedances for Power Transformers
IEEE Transactions on Power Delivery, 2020Accurate zero-sequence transformer data is important for correct fault analysis and protection settings. Utilities have been forced to approximate zero-sequence impedances for many three-legged core power transformers in service today that did not undergo testing for zero-sequence data at the factory before site installation. Where approximation of the
Haytham Saeed +4 more
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A novel technique for reducing leakage current by application of zero-sequence voltage
2014 International Power Electronics Conference (IPEC-Hiroshima 2014 - ECCE ASIA), 2014This paper proposes a technique for reducing the leakage current flowing into a power source as a conducted noise. This leakage current may have an adverse effect on the peripheral equipment, e.g., causing malfunctions. The proposed technique requires us to add a zero-sequence voltage to the output voltage reference of the inverter.
Hideki Ayano +2 more
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Rotor position estimation of ac machines using the zero sequence carrier signal voltage
Conference Record of the 2004 IEEE Industry Applications Conference, 2004. 39th IAS Annual Meeting., 2004This paper analyzes the sensorless control of AC machines based on the zero sequence voltage generated by the injection of a carrier signal voltage. The analysis focuses on rotor position estimation (tracking of rotor-position-dependent saliencies) but the methods discussed apply equally to flux position estimation (tracking of flux-dependent ...
F. Briz +3 more
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Air-Gap Flux Position Estimation of Inaccessible Neutral Induction Machines by Zero-Sequence Voltage
Electric Power Components and Systems, 2002This paper describes a new and straightforward approach to estimate the air-gap flux position in induction machines. The proposed scheme is based on the injection of a high-frequency oscillating stator voltage instead of a three-phase high-frequency voltage, thus allowing a reduction in audible noises and torque ripple. The main feature of the proposed
CONSOLI A +3 more
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IEEE Transactions on Power Delivery, 1991
Optical zero-sequence current-voltage transducers for detecting faults in nongrounded distribution networks were developed. The detection part can be electrically isolated from the ground by use of the divide method, in which there is a stray capacitance between line and ground.
E. Aikawa +4 more
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Optical zero-sequence current-voltage transducers for detecting faults in nongrounded distribution networks were developed. The detection part can be electrically isolated from the ground by use of the divide method, in which there is a stray capacitance between line and ground.
E. Aikawa +4 more
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Protection technique based on -zero sequence voltages for generator stator ground fault
IEE Proceedings - Generation, Transmission and Distribution, 2004A mathematical model on a coil basis is used to study the characteristics of the zero sequence voltage of a generator. The proposed technique for the stator ground fault detection simultaneously takes into account the fault contributed zero sequence fundamental voltage and the fault contributed third-harmonic voltage (Δ-zero sequence voltage).
N.L. Tai, Q. Ai
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A space vector modulation for a low zero-sequence voltage output
IEEE 2002 28th Annual Conference of the Industrial Electronics Society. IECON 02, 2003A space vector PWM (SVM) algorithm is designed to prevent zero-sequence currents between tandem inverters in three phase applications. The development is motivated and illustrated by a GTO/IGBT inverter system, feeding a large three phase motor. In applications where harmonic emissions are highly undesirable, the low power/fast switching IGBT is used ...
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