Particle-Initiated Breakdown Characteristics and Reliability Improvement in SF<sub>6</sub> Gas Insulation

Endo, Fumio; Yamagiwa, T.; Ishikawa, Toshio; Hosokawa, Masao

doi:10.1109/mper.1986.5528225

Cited by 19 publications

(5 citation statements)

References 4 publications

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“…Particle motions are charged near the electrode, influenced by discharge [25][26][27], characteristics of gas [28,29], and space charge [30][31][32]. With the strong randomness of the charging, the estimation is difficult, which brings errors to the description of particle motion model [33][34][35] and the calculation of lift-off field strength [36][37][38]. Therefore, it is important and necessary to study the factors affecting particle motion property.…”

Section: Section Headingmentioning

confidence: 99%

Particle trajectories and its charging behaviors: effect of gas type and electric field

et al. 2020

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Conductive particles in the gas insulated transmission lines (GIL) induce the breakdown between electrodes or the flashover along insulators. To solve the problem of particle moving and realize the particle-moving regulation, particle trajectories should firstly be determined in air and SF6. This paper presents the results of particle trajectories and its charging behaviors at vacuum and SF6, respectively. Metal particles with different materials and sizes were introduced and the charge quantity was calculated. The results showed that the particle lift-off electric field in SF6 was higher than that in air under the same gas pressure, that is, the charge on particle in SF6 was about 0.789 times lower than that in air under the same condition. Besides, the lift-off electric field of particle increased with the pressure increase of SF6. The charge on particle was affected by the concentration of electric field near particle and the electrical negative features of SF6. The work provided the data support for development of DC GIL in particle defect suppression.

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Section: Section Headingmentioning

confidence: 99%

Particle trajectories and its charging behaviors: effect of gas type and electric field

et al. 2020

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“…The design criteria of electric field strengths at the bushing and conductors were decided based on the reports for high voltage insulation in the gas [12][13][14]. Table 2 shows the design criteria of the electric field for multi-conductor bushing.…”

Section: Ultra High Voltage Transmissionmentioning

confidence: 99%

“…Particle levitation should be considered to avoid breakdown due to metal particle jump-up from the ground potential conductor. The particle levitation electric field is about 1.8 kV mm −1 for 5 mm metal particles which was assumed for this design [14].…”

Section: Ultra High Voltage Transmissionmentioning

confidence: 99%

Development of a dc 1 MV power supply technology for NB injectors

et al. 2006

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Major issues of NBI power supplies are a high-speed switching, regulation and transmission of dc ultra high voltage, and suppression of surge energy input to the beam source at breakdown. A GTO(gate turn off thyristor) inverter type power supply where the control is performed at low voltage ac side was designed for the ITER NB. Based on the remarkable progress of a high power IEGT (injection enhanced gate transistor), the design of the inverter has been modified to increase an efficiency and compactness using such new elements. A power loss in the inverter is reduced to be 30% of the GTO inverter system. For the transmission line of the dc UHV with intermediate voltages, a disk shape multi-conductor bushing with a transmission line test chamber has been developed. Dimensions of the bushing are 1.8 m in diameter and 140 mm in thickness at the edge. Electric fields at the conductor surface and insulator surface were designed to be lower than 5 kV/mm and 7 kV/mm, respectively. An electric field at the bottom of the ground potential outer conductor was designed to be lower than 1.2 kV/mm to prevent particle levitation which triggers breakdowns. The prototype transmission line has passed the standard impulse test up to 1,300 kV. A dc UHV up to 1,175 kV was successfully sustained for 300 s. To prevent the electric damage of the beam source at the breakdown, core snubbers using Fe-based nanocrystalline soft magnetic materials are adopted to dissipate the surge energy. 1) Hitachi Ltd. , 2) Toshiba Co.

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“…Research on discharge phenomena caused by particles inside GIS has been widely performed, focusing on breakdown initiated by particles [2][3][4], the firefly phenomenon [5,6], micro-gap discharge via particles located in proximity to the electrode [7], the characteristics of electric discharge via particles deposited on spacers [8][9][10], and movement of the particles around spacers [11]. Although discharge from a fixed needle electrode has been investigated in detail [12], there are few reports on the relationship between the movement of wire particles in an electric field and corona discharge occurring from the edges of particles.…”

Section: Introductionmentioning

confidence: 99%

Corona and micro‐gap discharge at a wire particle in precessional motion under a DC electric field

Kudo

Sugimoto

Higashiyama

2006

Electrical Engineering Japan

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SUMMARYA free wire particle located in an electric field between parallel plate electrodes manifests several motions: standing, precession on the electrode, crossing, and breakdown via the particle. During stable standing or precessional motion, the corona discharge inevitably occurs. To clarify the influence of discharge phenomenon on the behavior of the wire particle, the corona discharge characteristic of the particle in the precession was investigated experimentally in a DC electric field formed by parallel plate electrodes with a positive voltage applied to the upper electrode. The waveforms of the corona discharge current flowing through a 6-mm wire particle were measured under two conditions: when a free wire was in precession on the lower electrode and when a wire was fixed between the electrodes vertically with a spacing of less than 1 mm between the lower electrode and the bottom of the particle. From a comparison of the waveform of corona discharge occurring at the particle in precession with that of the fixed particle, it was found that both micro-gap discharge and negative corona occurred simultaneously only when the particle was in precession with a relatively small elevation angle. The particle was lifted up when the magnitude of the corona discharge current was decreased below about 15 µA.

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Particle-Initiated Breakdown Characteristics and Reliability Improvement in SF₆ Gas Insulation

Cited by 19 publications

References 4 publications

Particle trajectories and its charging behaviors: effect of gas type and electric field

Particle trajectories and its charging behaviors: effect of gas type and electric field

Development of a dc 1 MV power supply technology for NB injectors

Corona and micro‐gap discharge at a wire particle in precessional motion under a DC electric field

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Particle-Initiated Breakdown Characteristics and Reliability Improvement in SF6 Gas Insulation

Cited by 19 publications

References 4 publications

Particle trajectories and its charging behaviors: effect of gas type and electric field

Particle trajectories and its charging behaviors: effect of gas type and electric field

Development of a dc 1 MV power supply technology for NB injectors

Corona and micro‐gap discharge at a wire particle in precessional motion under a DC electric field

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Particle-Initiated Breakdown Characteristics and Reliability Improvement in SF₆ Gas Insulation