弧柱压降对塑壳断路器限流性能的作用

Effect of Arc Column Voltage on the Current Limiting Performance in Moulded Case Circuit Breaker

低压断路器依靠栅片分割电弧成短弧来熄灭电弧,传统的观点认为塑壳断路器限流作用主要依靠短弧的近极压降。从塑壳断路器尺寸紧凑、栅片数受限制出发,提出弧柱压降对限流同样起很大作用。用最新文献中提出的经验公式进行分析,并对一个实际塑壳断路器在带与不带灭弧栅片条件下进行分断试验,测量其电弧电压,说明弧柱压降对限流性能的贡献。用不同触头系统结构的断路器作对比实验,双向斥开的触头系统的分断性能高于单向斥开的触头系统,证实提高弧柱压降是一种有效的限流措施。

From traditional point of view, it is consideration that the current limiting performance of molded case circuit breaker （MCCB） depend on the electrode fail voltage due to the quenching method in low-voltage circuit breaker to be based on splitting the arc into a series of short arcs by deion plate. According to the compact geometry along with limited number of deion plates of MCCB, it was proposed that arc column voltage also play an important role in interrupting process of MCCB. In order to clarify the contribution of arc column voltage, the empirical expression of arc voltage for MCCB was used to make analysis, and the arc voltage was measured for with and without deion plates. The experiment to make comparison between repulsion only in movable contact side and both in movable and fixed contact sides was carried out, the latter has high current limiting feature, because elongation of the arc length causes the arc column voltage increase.