Experiment research on current chopping on zero period of DC vacuum circuit breaker breaking

Ultra‐fast disconnector (UFD) is a key component of hybrid DC circuit breakers and it is also studied as the main switch in some DC grid topologies. A UFD model suitable for DC grid studies and considering both normal operation and failure mode is presented. The dynamic motion of contacts is analysed in detail and it is concluded that Thomson coil inductances including parasitic parameters play an important role and it is recommended to use finite element modelling. The arcing mode of UFD is repressed using a variable resistance in series with an ideal switch. The variable resistance is calculated analytically based on the instantaneous position of contacts and the circuit conditions. Two different arc models are recommended: for the air‐insulated UFD and SF6 UFD, and in each case, two operating regimes should be considered: high and low currents. The UFD model is verified for both normal operation and failure mode using measurements on a 5 kV laboratory UFD and the results show very good matching. The 320 kV SF6 UFD model is evaluated using limited reported results from manufacturers.

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“…The chopping current may depend on the contact geometry, contact distance and applied voltage, but this variation is small, and it is assumed that

I_{chop}

is constant. This value is typically small [21], e.g.

I_{chop}

= 1 A in SF 6 [6], while in air UFD

I_{chop}

= 0.5 A.…”

Section: Ufd Failure Mode Modelmentioning

confidence: 99%

Detailed electro‐dynamic model of an ultra‐fast disconnector including the failure mode

2020

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“…During this phase, as the current continues to decrease, the arc current and arc voltage may become unstable and oscillatory because of the lack of plasma and metal vapor [20][21][22]. In recent years, the researches about the instability of arc current during the current-zero period mainly focus on the influence of the contact material and the parallel circuit parameters on the instability initiation and current chopping [23][24][25]. Some conclusions have been obtained.…”

Section: Introductionmentioning

confidence: 99%

Research on the current-zero period of vacuum arc interruption and equivalent model of post-arc gap

Li¹,

Yuan²,

Chen³

et al. 2021

J. Phys. D: Appl. Phys.

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In this paper, the current breaking experiments of vacuum interrupter are conducted and the waveforms of voltage and current are obtained. The results show that there is current instability phenomenon when the value of |di/dt| is low and the value of instability-initiation current decreases as the value of |di/dt| increases. The number of voltage spikes will also decrease and irregular oscillation will weaken. According to the experimental results and theoretical analysis, the 'memory characteristic' of plasma is proposed and a new mathematical model of post-arc initial plasma density is estabilished which will provides a new method for the calculation of the sheath growth. The equivalent circuit model of post-arc gap is established to analyze the transient recovery voltage. The equivalent parameters in the circuit are obtained by the calculation of sheath growth and plasma density and verified by comparison with measurements. Through the comparison of experimental results between the axial magnetic field (AMF) contact and the butt contact, the effects of AMF on post-arc plasma density and sheath growth are analyzed. The results show that AMF can make the post-arc plasma density higher and the sheath growth slower.

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Influence of External Transverse Magnetic Field on Post-arc Plasma Dissipation in Vacuum Interruption

Zhang,

Ma,

et al. 2023

2023 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices (ASEMD)

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Experiment research on current chopping on zero period of DC vacuum circuit breaker breaking

Cited by 4 publications

References 7 publications

Detailed electro‐dynamic model of an ultra‐fast disconnector including the failure mode

Detailed electro‐dynamic model of an ultra‐fast disconnector including the failure mode

Research on the current-zero period of vacuum arc interruption and equivalent model of post-arc gap

Influence of External Transverse Magnetic Field on Post-arc Plasma Dissipation in Vacuum Interruption

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