Evaluation of breakdown characteristics of gas insulated switchgears for non-standard lightning impulse waveforms - method for converting non-standard lightning impulse waveforms into standard lightning impulse waveforms -

Okabe, Shigemitsu; Yuasa, Sadayuki; Kaneko, Shuhei; Ueta, Genyo

doi:10.1109/tdei.2009.4784550

Cited by 38 publications

(13 citation statements)

References 7 publications

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“…13,14 Influence of the lightning impulsive waveform of the electrical discharge on breakdown characteristics was also investigated. 15,16 Even if SF 6 gas is a good switchgear, 17,18 it has a number of disadvantages, including a reduction in the breakdown field in the presence of metal particles and the fact that it contributes to the greenhouse effect. Therefore, it has been proposed [19][20][21][22][23] to use a mixture of nitrogen and SF 6 .…”

Section: Introductionmentioning

confidence: 99%

Analytical investigation of electrical breakdown properties in a nitrogen-SF6 mixture gas

et al. 2010

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The electrical breakdown properties in nitrogen gas mixed with SF6 are analytically investigated in this article by making use of the ionization and attachment coefficients of the mixed gas. The ionization coefficients of nitrogen and SF6 gas are obtained in terms of the electron temperature Te by assuming a Maxwellian distribution of the electron energy. The attachment coefficient of SF6 gas is also obtained in terms of the gas temperature Te. An algebraic equation is obtained, relating explicitly the electron breakdown temperature Tb in terms of the SF6 mole fraction χ. It was found from this equation that the breakdown temperature Tb increases from approximately 2 to 5.3 eV as the mole fraction χ increases from zero to unity. The breakdown temperature Tb of the electrons increases very rapidly from a small value and then approaches 5.3 eV slowly as the SF6 mole fraction increases from zero to unity. This indicates that even a small mole fraction of SF6 in the gas dominates the electron behavior in the breakdown system. The breakdown electric field Eb derived is almost linearly proportional to the breakdown electron temperature Tb. The experimental data agree remarkably well with the theoretical results. Therefore, it is concluded that even a small fraction of SF6 gas dominates nitrogen in determining the breakdown field. In this context, nearly 25% of the SF6 mole fraction provides a reasonable enhancement of the breakdown field for practical applications.

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Section: Introductionmentioning

confidence: 99%

Analytical investigation of electrical breakdown properties in a nitrogen-SF6 mixture gas

et al. 2010

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“…V cr is defined as the boundary region where the background electric field E b exceeds the critical value E cr for effective ionization (for SF 6 , (E/p) cr¨p = 88.5 kV/cm); v c is defined as the boundary of the space charge diffusion region. The dissipation time of the charge in the gas zone (t sw ) depends on the electric field distribution in front of the discharge channel [10].…”

Section: Discussionmentioning

confidence: 99%

“…Thus, PD detection could be simultaneously performed with withstand tests to exclude the critical defects arising from transportation and assembly [5]. In the past few decades, the gap breakdown in stressed SF6 gas under impulse conditions has been extensively studied [6][7][8]. Relevant theories based on the streamer and leader mechanisms have been developed by experiments [9] and simulations [10,11].…”

Section: Introductionmentioning

confidence: 99%

Partial Discharge Measurement under an Oscillating Switching Impulse: A Potential Supplement to the Conventional Insulation Examination in the Field

et al. 2016

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Partial discharge (PD) detection under oscillating switching impulse (OSI) voltage was performed on three types of insulation defects, including a protrusion on a conductor, a particle on an insulator surface, and a void in an insulator, which are three kinds of the common potential insulation hazards in gas insulated power apparatus. Experiment indicated that the PD sequences under OSI were composed of various combinations of the single pulse, the multiple pulses, and the reverse polarity pulse. The difference between the PD inception voltage (PDIV) and the breakdown voltage (BDV) under OSI voltage was greater than that under alternating current (AC) voltage in some cases, which can provide a more sufficient margin below the BDV for PD diagnosis. The OSI voltage also showed a better performance for exciting PDs with detectable magnitudes from small-scale defects, of which the AC voltage was incapable under our test conditions. The different PD activities with different interfaces under an impulse and a slowly varying voltage were speculated to be associated with the gradient of the background electric field and the space-charge mobility.

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“…In contrast, the failure characteristics of the OIP under the application of damped alternating oscillation impulses are much more complex [137][138][139]. When the oscillation frequency is increased from 200 Hz to 50 kHz, the OIP breakdown voltage initially decreases and then increases.…”

Section: Effects Of Waveform Parameters On the V-n Characteristicsmentioning

confidence: 99%

Review of accumulative failure of winding insulation subjected to repetitive impulse voltages

et al. 2019

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The premature failure phenomenon that occurs in solid insulation under the application of repetitive impulse voltages is known as the accumulative effect of impulse voltages on a solid dielectric. The accumulative failure of winding insulation is considered to be a core problem resulting from this phenomenon. The main problems include the accumulative failure of motor winding insulation under pulse-width modulation impulses and the accumulative failure of transformer winding insulation under the application of overvoltages, and these problems represent new challenges in the safe and stable operation of power grids. With regards to the above problems, this study reviews the results of recent research on the accumulative failure characteristics and mechanisms of winding insulation when subjected to repetitive impulse voltages. The challenges faced are discussed at the end of this study.

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Evaluation of breakdown characteristics of gas insulated switchgears for non-standard lightning impulse waveforms - method for converting non-standard lightning impulse waveforms into standard lightning impulse waveforms -

Cited by 38 publications

References 7 publications

Analytical investigation of electrical breakdown properties in a nitrogen-SF6 mixture gas

Analytical investigation of electrical breakdown properties in a nitrogen-SF6 mixture gas

Partial Discharge Measurement under an Oscillating Switching Impulse: A Potential Supplement to the Conventional Insulation Examination in the Field

Review of accumulative failure of winding insulation subjected to repetitive impulse voltages

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