Increase of Breakdown Voltage of a Non-Uniform Field Gap due to Pre-Ionization by Auxiliary Corona Discharge

1965 ◽  
Vol 4 (15) ◽  
pp. 385-386 ◽  
Author(s):  
Yasushichi Gosho
Keyword(s):  
Corona Discharge ◽  
Breakdown Voltage ◽  
Uniform Field

scholarly journals Lightning Impulse Breakdown Voltage of Rice Bran Oil for Transformer Application

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5084
Author(s):  
Mardhiah Hayati Abdul Hamid ◽  
Mohd Taufiq Ishak ◽  
Nur Sabrina Suhaimi ◽  
Jaafar Adnan ◽  
Nazrul Fariq Makmor ◽  
...  
Keyword(s):  
Weibull Distribution ◽  
Electric Fields ◽  
Breakdown Voltage ◽  
Rice Bran ◽  
Rice Bran Oil ◽  
Transformer Oil ◽  
Uniform Field ◽  
Testing Methods ◽  
Lightning Impulse ◽  
The Difference

Transformer oil does not only serve as an insulating liquid, but also in removing heat from the windings and cores. Mineral oil (MO) has been widely used in transformers for more than 150 years. Recently, researchers have attempted to search for alternative insulating oils due to the possibility that MO will run out in the future together with the concern on fire safety and environmental pollution. Among the potential oils is rice bran oil (RBO). This work presents the studies of the lightning impulse (LI) of RBO behavior under various electric fields, gap distances and testing methods. The electrical performances of LI tests show that RBO and Palm Oil (PO) have lower LI breakdown voltage than MO under both uniform and non-uniform electric fields. However, the difference in LI breakdown voltages between RBO, PO and MO are slightly small which is less than 20%. In addition, there is no significant effect in the various testing methods under both uniform field and non-uniform field where the percentages of difference are less than 12% and 8% respectively. The data of LI breakdown voltage were statistically analysed to predict the withstand voltage and 50% breakdown voltage of oil samples by using Weibull distribution. The Weibull distribution of MO, PO and RBO has well fit with the fitting line. Finally, the relationship between LI voltages under a non-uniform field with various parameters of PO and RBO was obtained and proposed. From this work, it can be concluded that RBO shows promising results to be considered as an alternative to MO in transformer applications.

scholarly journals Influence of the sign and magnitude of a surface charge on the breakdown voltage of a barrier corona discharge in Ar

2019 ◽  
Vol 1394 ◽  
pp. 012004
Author(s):  
Yu S Akishev ◽  
A A Balakirev ◽  
M A Medvedev ◽  
A V Petryakov ◽  
N I Trushkin
Keyword(s):  
Surface Charge ◽  
Corona Discharge ◽  
Breakdown Voltage

scholarly journals Lightning Breakdown Voltage Evaluation of Palm Oil and Coconut Oil as Transformer Oil under Quasi-Uniform Field Conditions

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2676 ◽  
Author(s):  
Nurul Katim ◽  
Mohd Ishak ◽  
Nur Mohamad Amin ◽  
Mardhiah Abdul Hamid ◽  
Khairol Amali Ahmad ◽  
...  
Keyword(s):  
Normal Distribution ◽  
Breakdown Voltage ◽  
Palm Oil ◽  
Coconut Oil ◽  
Cumulative Probability ◽  
Uniform Field ◽  
Multiple Level ◽  
Testing Methods ◽  
Distribution Fitting ◽  
Level Method

This paper presents lightning (1.2/50 µs) breakdown voltages of palm oil (PO), coconut oil (CO) and mineral oil (MO) in a quasi-uniform sphere to sphere electric field at two gap distances. The type of PO used in this study is Refined Bleached Deodorized Palm Oil (RBDPO) Olein type. The effect of voltage polarities (positive and negative) and testing methods (rising voltage, up and down and multiple level) on the lightning breakdown performance were investigated. The results indicated that lightning breakdown voltages of CO and RBDPO are comparable to those of MO under various test conditions. The results indicated that there is no polarity effect for lightning impulse breakdown tests in a quasi-uniform field. The testing methods, including rising voltage method, up and down method and multiple level method have a notable influence on the breakdown voltages. The effect of the 50% breakdown voltage on rising voltage method, up and down method and multiple level method for RBDPO and CO is comparable to MO. The withstand voltage at 1% and 50% breakdown probabilities were obtained using the Normal distribution fitting on the cumulative probability plot of impulse shots. Based on a normal distribution fitting, withstand voltages 1% breakdown probability of POA were close to the MO. Finally, based on statistical studies and simulation using ANSYS software, the prediction formulas for breakdown voltage for larger gap distances for all samples were derived.

High Performance of 5.7kV 4H-SiC JBSs with Optimized Non-Uniform Field Limiting Rings Termination

2016 ◽  
Vol 858 ◽  
pp. 986-989 ◽  
Author(s):  
Hao Yuan ◽  
Qing Wen Song ◽  
Xiao Yan Tang ◽  
Yu Ming Zhang ◽  
Hui Guo ◽  
...  
Keyword(s):  
Breakdown Voltage ◽  
Schottky Diode ◽  
High Performance ◽  
Figure Of Merit ◽  
Doping Concentration ◽  
Reverse Current ◽  
Uniform Field ◽  
Forward Current

In this paper, a 5.7kV 4H-SiC Junction Barrier Schottky diode(JBS) with non-uniform field limiting rings termination is simulated and fabricated successfully based on a epitaxial thickness of 49μm and the doping concentration about 1.04×1015cm-3 respectively. The reverse breakdown voltage could reach to 5.7kV at least at reverse current of 200μA. And the on-state voltage is 3V at the forward current of 2A, corresponding to an on-resistance of 32mΩ•cm2. The corresponding figure-of- merit of VB2/ RSP-ON for our fabricated device is 1.026 GW/cm2, which is closing to the optimal levels among several reported SiC JBS.

scholarly journals Impact of Shape and Total of Particle to Characteristics of Partial Discharge and Breakdown Voltage on Oil Insulation in Uniform Field

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Daniar Fahmi ◽  
I Made Yulistya Negara ◽  
R. Wahyudi ◽  
Dimas Anton Asfani ◽  
Made Yudhi Setyawan ◽  
...  
Keyword(s):  
Breakdown Voltage ◽  
High Voltage ◽  
Partial Discharge ◽  
Dielectric Strength ◽  
Solid Particles ◽  
Uniform Field ◽  
Negative Corona

Oil insulation is one of the insulation medium types commonly used in high voltage apparatus. This insulation is to separate between the conductive part and non-conductive part. However, oil insulation can experience decreasing of dielectric strength. It may be caused by the presence of solid particles. Therefore, the testing was conducted to obtain the effect of solid particles to characteristics of partial discharge and breakdown voltage of oil insulation. The results generally proved that the existence of solid particles can reduce the breakdown voltage value of oil insulation. In addition, the solid particles led to two types of corona on oil insulation, namely positive and negative corona.

scholarly journals Behavior of Biodegradable Oil under Impulse Voltages

2015 ◽  
Vol 785 ◽  
pp. 320-324 ◽  
Author(s):  
Nurul Izzatul Akma Katim ◽  
Mohd Taufiq Ishak ◽  
A.M. Ishak ◽  
M.Z.A.A. Kadir
Keyword(s):  
Breakdown Voltage ◽  
Palm Oil ◽  
Coconut Oil ◽  
Mineral Oil ◽  
Electrical Performance ◽  
Uniform Field ◽  
Testing Methods ◽  
Environmental Compatibility ◽  
Impulse Voltage ◽  
Lightning Impulse

The properties of Palm Oil (PO) and Coconut Oil (CO) offer the potential for transformers with non-toxicity, high fire and flash points and better environmental compatibility while compared with those filled with Mineral Oil (MO). This potential has led to intensive studies of electrical performance of biodegradable oil especially in evaluating the electrical performance under lightning impulse voltage in recent years. This paper presents the investigation on the impulse breakdown voltage of PO and CO in such a uniform field. The PO used in this study is Refined, Bleached and Deodorized Palm Oil (RBDPO) Olein type. Two testing methods, rising-voltage and up-and-down are considered for both oils with different gap distances (2.0 mm and 3.8 mm). Testing methods including rising-voltage method and up-and-down method have no notable influence on the breakdown voltages of RBDPOs and CO compared to MO.

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