scholarly journals FINITE ELEMENT MODELLING FOR ELECTRIC FIELD DISTRIBUTION AROUND POSITIVE STREAMERS IN OIL

2020 ◽  
Vol 58 (1) ◽  
pp. 56
Author(s):  
Dung Van Nguyen
Keyword(s):  
Finite Element ◽  
Electric Field ◽  
Field Distribution ◽  
Electric Field Distribution ◽  
Spherical Model ◽  
Shielding Effect ◽  
Geometrical Shape ◽  
Multiphysics Modelling ◽  
Positive Streamers ◽  
Simulation Results

Electric field distribution of positive streamers during propagation was determined with the finite element method by using COMSOL multiphysics. Modelling was performed at 210 kV and 270 kV. The geometrical shape of streamers was modelled with cylinder and sphere for the case of 210 kV while a growing cylinder was used for streamer propagation at 270 kV. In addition, a spherical model was used for determining the correlation between streamer branching and the electric field. It is obtained from the simulation results that the 2nd mode streamers has the electric field at channel tips of about 0.1 MV/cm while 8.3 MV/cm was received for the 4th mode streamers. The simulation results also reveal that the shielding effect resulting from streamer branching significantly reduces the electric field at the channel tips, and the shielding effect disappears with the angle a between channels is about 30o-60o depending on the size of streamer envelope. The hypothesis on correlation among velocity, streamer branching and electric field is suggested.

Voltage Distribution Studies in Polluted ZnO Arrester Using the FEMLAB

2011 ◽  
Vol 268-270 ◽  
pp. 412-417 ◽  
Author(s):  
Ferhat Tighilt
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Electric Field ◽  
Metal Oxide ◽  
Field Distribution ◽  
Electric Field Distribution ◽  
The Finite Element Method ◽  
Voltage Distribution ◽  
Distribution Studies ◽  
Long Operation

The voltage and electric field distribution in an arrester are very important for its long operation 15 kV with and without pollution. In order to clarify the influence of pollution severity conditions on metal oxide surge arrester, the finite element method (FEM) compilation of the voltage distribution in the ZnO column varistors under different pollution layer conductivity (200 μS, 70μS, 20μS) and clean was employed using the FEMLAB package.

Influence of Ring Length on Electric Field Distribution in CdZnTe Frisch-Ring Detector

2011 ◽  
Vol 695 ◽  
pp. 513-516
Author(s):  
Jie Ren ◽  
Li Fu ◽  
Ling Bao Meng
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Electric Field ◽  
Field Distribution ◽  
Energy Resolution ◽  
Electric Field Distribution ◽  
Element Method

The CdZnTe (CZT) devices with various screening depth in dimensions 3×3×6mm3 were fabricated. The influence of Ring length (screening depth) and length of crystal on the electric field distribution in CZT devices has been explored by finite element method. The results indicated that ring length (screening depth) plays an important role on the detecting performance of CZT Frisch-ring devices. Longer screening depth gives rise to an electric field which is compressed more greatly. Measured spectra indicated that extreme compressed electric field could reduce detecting resolution. A FWHM energy resolution of approximately 3.71% at 662 keV was obtained for a device with dimensions 3×3×6mm3 and 4.8mm screening depth.

Potential and Electric Field Distribution of 220kV Insulator String with a Faulty Insulator under Windage Yaw Condition

2014 ◽  
Vol 521 ◽  
pp. 317-320
Author(s):  
Hui Hui Li ◽  
Zheng Zheng ◽  
Hong Bo Chen ◽  
Huan Bai ◽  
Hua Zhao Zhang ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Field Strength ◽  
Electric Field ◽  
Field Distribution ◽  
Electric Field Distribution ◽  
Field Distributions ◽  
Space Potential ◽  
Suspension Insulator ◽  
Variation Characteristics

Faulty insulators could appear in the HV transmission line insulator string under the comprehensive effect of electrical, mechanical and environmental factors and they can be detected according to the space potential and electric field distribution variation characteristics around the insulator string. Finite Element Method (FEM) was used to study the potential and electric field distributions of a 220kV suspension insulator string contained a zero-value insulator in windage condition, comparing with a fine insulator string. The results show that the variation of the space potential and electric field distributions of insulator string is the same as that under no windage condition. The curve of synthetic electric field along the central axis around the good insulator string is U-shape. The 10th and 11th insulators from the high-voltage end are the sensitive insulators where the distortion ratio of synthetic field strength is higher than 3%, when a faulty insulator is in the string. This result can provide preferences for the online detection of faulty insulators.

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