Results 261 to 270 of about 399,584 (308)

An overview of shaft voltages and bearing currents in rotating machines

2016 IEEE Industry Applications Society Annual Meeting, 2016
Shaft voltages and associated "shaft currents" or "bearing currents" have been known since more than a century on DC and AC motors under classical line operation. More recently with the emergence of inverter drives, there has been an increase of high-frequencies bearing currents and shaft voltages creating mainly premature failure of bearings. Although
Thibaud Plazenet, Thierry Boileau, Cyrille Caironi, Babak Nahid-Mobarakeh   +3 more
openaire   +2 more sources

Characteristics of Shaft Voltage and Bearing Currents

IEEE Industry Applications Magazine, 1997
This article reviews investigations into reduced bearing life due to voltage source adjustable speed drive (ASD) AC motor operation. Relevant bearing failure mechanisms and indicators are discussed. dv/dt and electric discharge machining (EDM) contributions are discussed and experimental data presented showing the voltage levels on motor shafts when ...
Dave Busse, Jay Erdman, Russ Kerkman, Dave Schlegal, Gary Skibinski   +4 more
openaire   +1 more source

Antiforce Current Bearing Waves

2012
In the case of breakdown waves in a long discharge tube, near the electrode where the potential gradient in the gas is greatest, small quantity of gas is ionized. Analysis of the spectrum of radiation emitted from electric breakdown of a gas reveals no Doppler shift, indicating that the ions have negligible motion. The large difference in mobilities of
M. Hemmati, W. Childs, H. Shojaei, D. Waters   +3 more
openaire   +1 more source

Detection of balls bearing Incipient defect by current analysis

IECON 2021 – 47th Annual Conference of the IEEE Industrial Electronics Society, 2021
The bearing problem is considered as the first factor responsible of defects in the electric machines. Traditionally, rolling monitoring is based on the analysis of vibration signals requiring sensors around the machine. The objective of our research work is based on the analysis of electromagnetic signals (current, voltage, stray flux) to detect ...
Mahamad Hassan Gaditto, Bruno Vacossin, Amine Yazidi, Humberto Henao, Franck Betin, Eric Segard   +5 more
openaire   +1 more source

Bearing currents and their relationship to PWM drives

IEEE Transactions on Power Electronics, 1997
This paper examines AC motor shaft voltages and the resulting bearing currents when operated under pulse width modulation (PWM) voltage source inverters. The paper reviews the mechanical and electrical characteristics of the bearings and motor in relation to shaft voltages and bearing currents.
D. Busse, J. Erdman, R.J. Kerkman, D. Schlegel, G. Skibinski   +4 more
openaire   +1 more source

Bearing currents in wind turbine generators

Journal of Renewable and Sustainable Energy, 2013
Increasing the availability of multi-megawatt wind turbines (WT) is necessary if the cost of energy generated by wind is to be reduced. It has been found that WT generator bearings have a surprisingly high failure rate, with failures happening too early to be due to classical rolling contact fatigue.
M. Whittle, J. Trevelyan, P. J. Tavner
openaire   +1 more source

Statistical approach to discharge bearing currents

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, 2010
PurposeThe purpose of this paper is to propose a statistical approach, which enables the prediction of the risk of the appearance of discharge bearing currents in a given drive that can damage the motor bearings. Using such an approach, the drives for the decisive but expensive, long‐term destructive investigations can be selected.
Robert Smolenski, Adam Kempski, Jacek Bojarski   +2 more
openaire   +1 more source

Analysis of an Eddy Current Journal Bearing

Journal of Tribology, 1988
Nearly all magnetic bearings which have found use in modern technology are based on the attractive force between a magnet and a magnetic material. A distinct disadvantage is that such devices are inherently unstable and require active feedback for operation.
K. A. Connor, J. A. Tichy
openaire   +1 more source

Mineral deposition in current meter bearings

Deep Sea Research and Oceanographic Abstracts, 1975
Abstract Carbonate deposits (siderite, aragonite and calcite) have been identified within current meter bearings. These deposits were observed to inhibit and even prevent the response of sensors mounted on the bearings. The mechanism of precipitation of these minerals is described, with particular reference to the increased reaction rate found when ...
Stephen C. Dexter, John D. Milliman, William J. Schmitz   +2 more
openaire   +1 more source

Current limits of PTFE in sliding bearings

IABSE Reports, 2010
<p>The European standard EN 1337 on bridge bearings is supported by experimental studies dating to the ‘70s and the ‘80s, which are not suitable to account for recent issues relevant to operations of steel–PTFE bridge bearings under extreme conditions, like high environment temperatures or high velocities of sliding.
QUAGLINI, VIRGINIO, C. TAVECCHIO, DUBINI, PAOLO, CUMINETTI, DANIELE, FERRONI, DANIELA   +4 more
openaire   +2 more sources