Influence of Moisture on the Space Charge Migration and Electric Field Behavior in Oil-Paper Insulation

2014 ◽  
Vol 644-650 ◽  
pp. 3548-3551 ◽  
Author(s):  
Jin Fu ◽  
Jian Hao ◽  
Hua Yin ◽  
Gao Lin Wu ◽  
Qian Wang
Keyword(s):  
Moisture Content ◽  
Electric Field ◽  
Space Charge ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Insulation System ◽  
Charge Migration ◽  
Electrical Breakdown Strength ◽  
The Difference ◽  
Paper Insulation

Moisture has a detrimental effect on oil-paper insulation life by lowering electrical breakdown strength. How does the space charge behavior of the oil-paper insulation system consisted by oil gap and oil immersed insulation pressboard with different moisture content? The space charge characteristics of the mixed insulation consisted of oil gap and pressboard with three moisture content were investigated using the PEA measurement system. The space charge accumulation behaviors at the interface between oil gap and pressboard were analyzed. The distortion of the electrical field in the oil gap and pressboard was also analyzed. Results show that there are many charges injected into the oil and the pressboard. The charges accumulated at the interface between oil gap and pressboard. The charges accumulated in the mixed insulation system become less with the moisture content increased. The difference of the electric field strength in the oil gap and pressboard become smaller with the moisture content increased.

scholarly journals Electrical Breakdown Strength and Space Charge Distribution ofAcrylic Acid-Graft-Polyethylene

2000 ◽  
Vol 120 (5) ◽  
pp. 589-594
Author(s):  
Chang-Ryong Lee ◽  
Toshinao Takeda ◽  
Naohiro Hozumi ◽  
Hiroshi Suzuki ◽  
Tatsuki Okamoto
Keyword(s):  
Space Charge ◽  
Charge Distribution ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Space Charge Distribution ◽  
Electrical Breakdown Strength

Simulation on motion characteristics of space charge in single oil-paper insulation

2017 ◽  
Vol 36 (6) ◽  
pp. 1663-1675 ◽  
Author(s):  
Zhifei Yang ◽  
Zhiye Du ◽  
Jiangjun Ruan ◽  
Shuo Jin ◽  
Guodong Huang ◽  
...  
Keyword(s):  
Electric Field ◽  
Space Charge ◽  
Electric Field Intensity ◽  
Single Layer ◽  
Simulation Method ◽  
Insulation System ◽  
Content Type ◽  
Space Charges ◽  
Paper Insulation ◽  
Total Electric Field

Purpose The purpose of this paper is numerical calculation of total electric field in oil-paper insulation. Now, there is no effective method to consider the influence of space charges when calculating the total electric field distribution in the main insulation system of the valve-side winding of an ultra-high-voltage direct current converter transformer. Design/methodology/approach To calculate the total electric field in an oil-paper insulation system, a new simulation method in single-layer oil-paper insulation based on the transient upstream finite element method (TUFEM) is proposed, in which the time variable is considered. The TUFEM is used to calculate the total electric field in an oil-paper insulation system by considering the move law of space charges. The simulation method is verified by comparing the simulation results to the test data. The move law of space charges and distribution characteristics of the electric field under difference voltage values in single-layer oil-paper insulation were presented. Findings The results show that the TUFEM has an excellent accuracy compared with the test data. When carrier mobility is a constant, the time to reach the steady state is inversely correlated with the initial electric field intensity, and the distortion rate of the internal total electric field is positively correlated with the initial electric field intensity. Originality/value This paper provides an exploratory research on the simulation of space charge transport phenomenon in oil-paper and has guiding significance to the design of oil-paper insulation.

Development of Dielectric Elastomer Actuators - Part I: Performance of Polyurethane Film Actuators with Dangling Chains and Network Structures

2012 ◽  
Vol 557-559 ◽  
pp. 1852-1856 ◽  
Author(s):  
Takeshi Fukuda ◽  
Zhi Wei Luo ◽  
Aya Ito
Keyword(s):  
Electric Field ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Dielectric Elastomer ◽  
Toluene Diisocyanate ◽  
Polypropylene Glycol ◽  
Dielectric Elastomer Actuators ◽  
Polyurethane Film ◽  
Electrical Breakdown Strength ◽  
Lower Electric Field

Dielectric elastomer actuators with enhanced flexibility were prepared by thermosetting polyurethane (TSU) consisting of polypropylene glycol (PPG) as an active hydrogen component and toluene diisocyanate (TDI) as an isocyanate component. The improvement was achieved by less hard segment content, i.e. less isocyanate index, the synthesized film actuators were compared with the actuator softened using a plasticizer. It was found that the film actuators prepared by this method had significant advantages in actuation under a lower electric field as well as the increase of electrical breakdown strength and of strain. Furthermore, the mechanically-stretched effect of the films was also evaluated. It turned out that prestrain up to 200% was effective in the increase of electrical breakdown strength while maintaining the actuation under a lower electric field. However, prestrain over 200% caused a decrease in actuation under a lower electric field.

LIGHTNING IMPULSE BREAKDOWN CHARACTERISTICS AND ELECTRODYNAMIC PROCESS OF INSULATING VEGETABLE OIL-BASED NANOFLUID

2012 ◽  
Vol 26 (15) ◽  
pp. 1250095 ◽  
Author(s):  
JIAN LI ◽  
ZHAO-TAO ZHANG ◽  
PING ZOU ◽  
BIN DU ◽  
RUI-JIN LIAO
Keyword(s):  
Space Charge ◽  
Vegetable Oil ◽  
Vegetable Oils ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Environment Friendly ◽  
Mineral Oils ◽  
Lightning Impulse ◽  
Electrical Breakdown Strength ◽  
Charging Dynamics

Insulating vegetable oils are considered environment-friendly and fire-resistant substitutes for insulating mineral oils. This paper presents the lightning impulse breakdown characteristic of insulating vegetable oil and insulating vegetable oil-based nanofluids. It indicates that Fe 3 O 4 nanoparticles can increase the negative lightning impulse breakdown voltages of insulating vegetable oil by 11.8% and positive lightning impulse breakdown voltages by 37.4%. The propagation velocity of streamer is reduced by the presence of nanoparticles. The propagation velocities of streamer to positive and negative lightning impulse breakdown in the insulating vegetable oil-based nanofluids are 21.2% and 14.4% lesser than those in insulating vegetable oils, respectively. The higher electrical breakdown strength and lower streamer velocity is explained by the charging dynamics of nanoparticles in insulating vegetable oil. Space charge build-up and space charge distorted filed in point-sphere gap is also described. The field strength is reduced at the streamer tip due to the low mobility of negative nanoparticles.

Electrical breakdown strength enhancement in aluminum scandium nitride through a compositionally modulated periodic multilayer structure

2021 ◽  
Vol 130 (14) ◽  
pp. 144101
Author(s):  
Jeffrey X. Zheng ◽  
Dixiong Wang ◽  
Pariasadat Musavigharavi ◽  
Merrilyn Mercy Adzo Fiagbenu ◽  
Deep Jariwala ◽  
...  
Keyword(s):  
Multilayer Structure ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Scandium Nitride ◽  
Strength Enhancement ◽  
Electrical Breakdown Strength
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