scholarly journals AC Breakdown Characteristics of c-C4F8/N2 Gas Mixtures in an Extremely Non-Uniform Electric Field

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3533 ◽  
Author(s):  
Lin Lin ◽  
Qingguo Chen ◽  
Xinyu Wang ◽  
Hui Zhang ◽  
Haoran Feng ◽  
...  
Keyword(s):  
Electric Field ◽  
Breakdown Voltage ◽  
Volume Fraction ◽  
Low Voltage ◽  
Environmentally Friendly ◽  
Gas Pressure ◽  
Uniform Electric Field ◽  
Electrode Spacing ◽  
Electrode Distance ◽  
Liquefaction Temperature

Octafluorocyclobutane (c-C4F8) is one of the environmentally friendly gases with the potential to replace SF6. In this paper, the AC breakdown characteristics of c-C4F8/N2 mixture in an extremely non-uniform electric field were studied; the effects of the gas pressure, electrode distance, and c-C4F8 volume fraction on the breakdown voltage were analyzed; and the feasibility of replacing SF6 with c-C4F8/N2 was verified. The results show that the breakdown voltage of c-C4F8 /N2 increases with an increase in pressure, electrode spacing, and volume fraction of c-C4F8 in an extremely non-uniform electric field. Under the same conditions, the breakdown voltage of 20%c-C4F8/80%N2 is 46–90% that of 20%SF6/80%N2. When the pressure is 0.3 MPa, the 20%c-C4F8/80%N2 breakdown voltage can reach over 57% that of SF6. Taking into consideration the environment, liquefaction temperature, and insulation strength, 20%c-C4F8/80%N2 may replace SF6 used for medium- and low-voltage equipment.

INFLUENCE OF PARTICLE SIZE ON THE DYNAMIC STRENGTH OF ELECTRORHEOLOGICAL FLUIDS

1994 ◽  
Vol 08 (20n21) ◽  
pp. 2835-2853 ◽  
Author(s):  
YUNG-HUI SHIH ◽  
HANS CONRAD
Keyword(s):  
Particle Size ◽  
Electric Field ◽  
Volume Fraction ◽  
Low Voltage ◽  
Silicone Oil ◽  
Particle Surface ◽  
Dynamic Strength ◽  
Columnar Structure ◽  
Particle Surface Area ◽  
Polarization Component

The electrical properties, rheology and structure of model ER fluids consisting of glass beads in silicone oil were investigated as a function of electric field E (0–4 kV/mm ), particle size D (6–100 µ m ) and shear rate [Formula: see text]. The conductivity of the suspensions was 3 orders of magnitude greater than that of the host oil at E ⋝ 1 kV/mm ; their low-voltage d.c. permittivity was about 1.35 times larger. The flow stress of the suspensions was given by [Formula: see text] where τE is the polarization component and τ vis the viscous component. The linear dependence of τE on E was attributed to dipole saturation. The observed opposing effects of D and [Formula: see text] on τE were concluded to result from their respective influence on the strength of the columnar structure normally produced by the electric field and its fragmentation during shear. The constant C1 was in agreement with the Einstein equation for the effect of volume fraction of particles on the viscosity of suspensions. The parameter C2/D was concluded to reflect either the effect of particle surface area on viscosity or a polydispersion effect. The present results did not correlate with the Mason number as normally formulated, but did when it was appropriately modified.

Perimeter Gated Single Photon Avalanche Diodes in Sub-Micron and Deep-Submicron CMOS Processes

2018 ◽  
Vol 27 (03n04) ◽  
pp. 1840018
Author(s):  
Mst Shamim Ara Shawkat ◽  
Mohammad Habib Ullah Habib ◽  
Md Sakib Hasan ◽  
Mohammad Aminul Haque ◽  
Nicole McFarlane
Keyword(s):  
Electric Field ◽  
Field Distribution ◽  
Breakdown Voltage ◽  
Gate Voltage ◽  
Electric Field Distribution ◽  
Device Simulation ◽  
Deep Submicron ◽  
Uniform Electric Field ◽  
Cmos Process ◽  
Submicron Process

A perimeter gated SPAD (PGSPAD), a SPAD with an additional gate terminal, prevents premature perimeter breakdown in standard CMOS SPADs. At the same time, a PGSPAD takes advantage of the benefits of standard CMOS. This includes low cost and high electronics integration capability. In this work, we simulate the effect of the applied voltage at the perimeter gate to develop a consistent electric field distribution at the junction through physical device simulation. Additionally, the effect of the shape of the device on the electric field distribution has been examined using device simulation. Simulations show circular shape devices provide a more uniform electric field distribution at the junction compared to that of rectangular and octagonal devices. We fabricated PGSPAD devices in a sub-micron process (0.5 μm CMOS process and 0.5 μm high voltage CMOS process) and a deep-submicron process (180 nm CMOS process). Experimental results show that the breakdown voltage increases with gate voltage. The breakdown voltage increases by approximately 1.5 V and 2.5 V with increasing applied gate voltage magnitude from 0 V to 6 V for devices fabricated in 0.5 μm and 180 nm standard CMOS process respectively.

scholarly journals A Study on the Lightning Impulse Breakdown Voltages of Palm Oil and Coconut Oil by Different Methods

2015 ◽  
Vol 793 ◽  
pp. 9-13 ◽  
Author(s):  
Y.V. Thien ◽  
N. Azis ◽  
J. Jasni ◽  
Mohd Zainal Abidin Ab Kadir ◽  
Robiah Yunus ◽  
...  
Keyword(s):  
Electric Field ◽  
Breakdown Voltage ◽  
Palm Oil ◽  
Coconut Oil ◽  
Uniform Electric Field ◽  
Testing Methods ◽  
Different Types ◽  
Lightning Impulse ◽  
Potential Alternative ◽  
Voltage Performance

In recent years, there have been a number of interests on the Palm Oil (PO) and Coconut Oil (CO) as a potential alternative dielectric insulating fluid in transformers which stimulate different types of studies on these oils properties. Among the important studies is the lightning impulse properties. This paper presents the investigation on the lightning impulse breakdown voltage of PO and CO under non-uniform electric field. The PO used in this study is Refined, Bleached and Deodorized Palm Oil (RBDPO) Olein type. The influence of the testing methods, rising-voltage and up-and-down are investigated at 2 gap distances for both oils. It was found that the lightning breakdown voltage performance for some of the RBDPO and CO are comparable to MO.

Research of Discharge Characteristics of CO2 Gas in Small Distance

2013 ◽  
Vol 860-863 ◽  
pp. 2194-2198
Author(s):  
Quan Wang ◽  
Huan Wang ◽  
Qiong Xiang
Keyword(s):  
Electric Field ◽  
Breakdown Voltage ◽  
Dielectric Strength ◽  
Small Distance ◽  
Uniform Electric Field ◽  
Key Indicator ◽  
Discharge Device ◽  
Power Frequency ◽  
Gas Insulation ◽  
Insulating Properties

In order to find a new kind of insulates gas to substitute for SF6 gas, a discharge device has been development with shifter electrodes and adjusts distances automatic. Uniform electric field, non-uniform electric field had been achieved in this discharge device. The power-frequency voltage-withstand test of CO2 gas has been taken in these three kinds of electric field. In this test, data of breakdown voltage were obtained under different pressure and distances of electrodes with 99.99% purity of CO2. It can be seem from these data that the value of breakdown voltage is positive correlation to pressure and distances of electrodes. Whats more? For uniform electric field, the dielectric strength meet the requirement of power-frequency voltage-withstand of 110kV gas insulation device when the distance of test electrodes no less than 30mm. For non-uniform electric field, the dielectric strength of gas insulation of CO2 gas has little difference until the pressure increased to 0.5MPa. According to the data of power-frequency voltage-withstand test it can be conclude that the 0.5MPa is a key indicator to improve the insulating properties.

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