This article extends the quantitative method of optimizing the opening velocities for a vacuum circuit breaker (VCB) with cup-type axial magnetic field (AMF) contacts. The material of the AMF contact is Cu50Cr50. We define v1 as the initial opening velocity over half the full contact gap and v2 as the average velocity over the full contact gap of 20 mm. We optimize v1 and v2 using the transition of anode-discharging modes, of which we combine the footpoint mode and anode spot mode into a large-gap high-current (LGHC) mode. The experiment shows that v1 should be higher than a threshold velocity v1_th, which corresponds to a peak critical contact gap d1_th for the transitions of an intense arc mode into a diffuse arc mode, in high-current interruption. The higher v1 is than v1_th, the faster the intense arc mode evolves into the diffuse arc mode. This helps successfully interrupt the short-circuit current in a short arcing time. Another threshold velocity, v2_th, corresponds to the maximum critical contact dII_th for the formation of an LGHC mode in the second arc current half-wave. A high v1 design needs v2 to be lower than v2_th. The lower v2 is than v2_th, the better the VCB avoids the LGHC mode in high-current interruption. This helps interruption over a long arcing time. We propose an intelligent opening and breaking operation for VCBs with cup-type AMF contacts, whereby the VCB opens with different opening velocities according to the short-circuit current level.

中文翻译：

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优化杯型轴向磁场触头真空断路器的分闸速度


本文扩展了优化具有杯型轴向磁场 (AMF) 触头的真空断路器 (VCB) 分闸速度的定量方法。 AMF触点的材质为Cu50Cr50。我们将 v1 定义为半个完整接触间隙上的初始打开速度，将 v2 定义为 20 mm 完整接触间隙上的平均速度。我们利用阳极放电模式的转变来优化 v1 和 v2，其中我们将足点模式和阳极点模式组合成大间隙高电流（LGHC）模式。实验表明，v1应高于阈值速度v1_th，该阈值速度对应于大电流中断时强电弧模式向扩散电弧模式转变的峰值临界接触间隙d1_th。 v1 比 v1_th 越高，强烈电弧模式演变成扩散电弧模式的速度越快。这有助于在短飞弧时间内成功中断短路电流。另一个阈值速度v2_th对应于在第二电弧电流半波中形成LGHC模式的最大临界接触dII_th。高 v1 设计需要 v2 低于 v2_th。 v2 比 v2_th 越低，VCB 越能避免大电流中断时的 LGHC 模式。这有助于在较长的燃弧时间内中断。我们为带有杯型 AMF 触点的 VCB 提出了一种智能分闸和分断操作，其中 VCB 根据短路电流水平以不同的分闸速度分闸。