scholarly journals Analysis and Mitigation of Stray Capacitance Effects in Resistive High-Voltage Dividers

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2278
Author(s):  
Jordi-Roger Riba ◽  
Francesca Capelli ◽  
Manuel Moreno-Eguilaz

This work analyzes the effects of the parasitic or stray distributed capacitance to ground in high-voltage environments and assesses the effectiveness of different corrective actions to minimize such effects. To this end, the stray capacitance of a 130 kV RMS high-voltage resistive divider is studied because it can severely influence the behavior of such devices when operating under alternating current or transient conditions. The stray capacitance is calculated by means of three-dimensional finite element analysis (FEA) simulations. Different laboratory experiments under direct current (DC) and alternating current (AC) supply are conducted to corroborate the theoretical findings, and different possibilities to mitigate stray capacitance effects are analyzed and discussed. The effects of the capacitance are important in applications, such as large electrical machines including transformers, motors, and generators or in high-voltage applications involving voltage dividers, conductors or insulator strings, among others. The paper also proves the usefulness of FEA simulations in predicting the stray capacitance, since they can deal with a wide range of configurations and allow determining the effectiveness of different corrective configurations.

2012 ◽  
Vol 614-615 ◽  
pp. 1226-1229
Author(s):  
Dong Wei Qiao ◽  
Xiu He Wang ◽  
Chang Qing Zhu

In consideration of low power density of electric excitation claw-pole alternator (EECA) and some difficulties in magnetic field regulation of permanent magnet claw-pole alternator (PMCA), a novel hybrid excitation brushless claw-pole alternator (HEBCA) is proposed in this paper. Its structure and field control principle are described. Three dimensional finite element analysis is used to obtain the no-load magnetic field distributions and field control capability under different field currents. The result shows that the flux of the prototype machine can be adjusted over a wide range with a relatively low field current


Author(s):  
Ahalapitiya H. Jayatissa ◽  
Himabindu Gadupudi

A novel piezoelectrically actuated micropump was designed and its characteristics were simulated. The proposed structure of micropump consists of a polymer pipe coated with three curved piezoelectric strips, which actuate the polymer pipe walls using an external power source. A three dimensional finite element analysis (FEA) was used to study the deformation in the polymer pipe. The pump prototype comprises three semi-cylindrical discs made of PZT-5H and a polyimide pipe; PZT discs are placed on the opposite sides of a polyimide pipe. The structure was simulated for a wide range of voltages and frequencies. The stroke volume of the micropump was calculated using the deformation profiles obtained from the FEA. The results indicated that the change of stroke volume of pipe was functions of both voltage and frequency of power. Also there were few peak points of stroke volume associated with bending mode of piezoelectric strips. At the lower frequency (<1 KHz) and voltage regions (<100 V), a flow rate of few μl/min could be achieved for a pump designed with check values at the end of the pipe.


2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.


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