Results 281 to 290 of about 11,639,860 (350)

Harmonic measurements: current and voltage transducers

199 IEEE Power Engineering Society Summer Meeting. Conference Proceedings (Cat. No.99CH36364), 2003
An overview of the development of special current and voltage transducers at the National Research Council of Canada for accurate measurements of harmonics in power systems will be presented. The transducers include two-stage and electronically-aided instrument transformers, openable-core AC and AC/DC current transformers, multi-stage clamp-on current ...
openaire   +1 more source

Inductive load current harmonic injection

Proceedings of the Thirty-Fourth Southeastern Symposium on System Theory (Cat. No.02EX540), 2003
Induction motor audible noise can be related to the frequency content present in the stator winding currents. These currents produce time varying air gap fluxes which in turn produce exciting forces resulting in vibrations in the mechanical structure. By adding harmonics into the winding currents, additional frequencies can be added to the air gap flux
B. Brzezinski, J. Parker, T.A. Haskew, J. Murphree, D.J. Jackson   +4 more
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Quasi-Resonant Control for Harmonic Current Suppression of a Magnetically Suspended Rotor

IEEE transactions on power electronics, 2019
In the magnetically suspended rotor (MSR) system of the flywheel, harmonic current produced mainly by mass imbalance and sensor runout would cause undesirable harmonic vibration.
Peiling Cui, Guoxi Zhang, Zhiyuan Liu, Han Xu   +3 more
semanticscholar   +1 more source

Dual Third-Harmonic-Current Excitation Principle of a Brushless Synchronous Machine Based on Double Three-Phase Armature Windings

International Conference on Electrical Machines and Systems, 2019
Traditional harmonic excitation synchronous machine can only be used for generator. One of the main reasons why the harmonic excitation synchronous machine can not be used as a motor is that the field current of the harmonic excitation synchronous ...
Fei Yao, Dongyang Sun, Lizhi Sun, T. Lipo   +3 more
semanticscholar   +1 more source

Current Harmonics Measurement by Means of Current Transformers

IEEE Transactions on Power Delivery, 2007
This paper analyzes the accuracy of current transformers (CT) when excited with nonsinusoidal currents. It uses a nonlinear model that accounts for the minor hysteresis loop of the core. It was concluded that instrument transformers with accuracy class 0.6 or better provide reasonably accurate measurements of current harmonics magnitudes, however the ...
Alexander E. Emanuel, John A. Orr
openaire   +1 more source

Second-Harmonic Current Reduction for Two-Stage Inverter With Boost-Derived Front-End Converter: Control Schemes and Design Considerations

IEEE transactions on power electronics, 2018
The instantaneous output power of the two-stage single-phase inverter pulsates at twice the output frequency $(2f_{{\rm{o}}})$, generating notorious second-harmonic current (SHC) in the front-end dc–dc converter and the input dc voltage source.
Li Zhang, X. Ruan, X. Ren
semanticscholar   +1 more source

Current harmonics in nonlinear resistance circuits

Electrical Engineering, 1935
A semigraphical method of solving for harmonics in the input current to a network containing any number of linear and nonlinear resistances in any combination, when a sinusoidal voltage is applied across the network, is presented herewith. The treatment is restricted to nonlinear resistances in which the d-c volt-ampere characteristic is the same ...
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Harmonic-current-restrained relays for differential protection

Electrical Engineering, 1938
DIFFERENTIAL relaying is the commonly accepted means of protecting large power transformers, a-c generators, and station bus systems against internal faults.1 The methods and circuits employed in various instances, while differing in detail, are all fundamentally the same in basic principle.
L. F. Kennedy, C. D. Hayward
openaire   +1 more source

Control Schemes for Reducing Second Harmonic Current in Two-Stage Single-Phase Converter: An Overview From DC-Bus Port-Impedance Characteristics

IEEE transactions on power electronics, 2018
The instantaneous input and output power of two-stage single-phase converter are imbalanced, resulting in the second harmonic current (SHC) in the dc–dc converter, dc source, or dc load.
Li Zhang, X. Ruan
semanticscholar   +1 more source

Alternating current sensor with second-harmonic detection

Applied Optics, 2000
We describe a novel optical sensor based on the Faraday effect for measuring ac. The sensing element is a piece of material of high Verdet constant placed between polarizers. When the angle between the polarizers differs by 45 degrees, a signal of twice the frequency of the ac is generated--in addition to the usual signal with the same frequency as the
J A, Ferrari, C D, Perciante, A, Dubra, A, Arnaud, E M, Frins   +4 more
openaire   +2 more sources