双断点塑壳断路器的可靠性应用

Reliability Application of Double Break Point Molded Case Circuit Breakers

简述双断点塑料外壳式断路器的灭弧结构。为了提高塑壳断路器的分断能力,采用双断点方式,在出现电路故障时,断路器的动静触头在洛伦兹力和霍姆力的双重作用下快速打开一定的距离,此时双断点同时分断,在两个端点处同时产生电弧,从而快速增加电路电阻,降低故障电路电流。电弧产生后会形成高压气流,在触头盒子密封的情况下,高压空气将电弧吹向灭弧室。同时,在铁芯被电弧磁化的情况下,利用磁吹原理,将电弧吹入灭弧室,在灭弧室将电弧熄灭。通过计算与仿真,断路器的双断点触头盒子的密封结构完全可实现更高的分断能力。通过短路分断的试验结果可以看出,断路器在分断电流出现后5ms左右实现快速分断,限制电流继续提高,在气吹与磁吹的双重作用下,电弧迅速熄灭,从而实现150kA的高分断水平。分析和试验数据的双重验证表明,双断点结构对于快速分断和限流有重要作用,气吹和磁吹结构对电弧的快速熄灭有重要作用。在上述结构作用下,塑壳断路器的分断能力翻倍成为可能。另外,双断点塑壳断路器面向高端客户群,产品设计精度和强度都较高,能够保证开关高可靠运行,充分满足各种复杂应用环境的需求。

This paper briefly describes the double breakpoint plastic shell type circuit breaker arcing structure,in order to improve the breaking ability of molded case circuit breaker,with the method of double breakpoints,in case of circuit failure,the breaker of contactor in lorentz force and under the dual role of Homer force,quickly open the distance,the double breakpoint breaking at the same time,in the two endpoints at the same time produce arc,thus rapidly increasing resistance,reduce the fault circuit current,arc generated after,can form high pressure air flow,in the case of a contact box seal,high pressure air will be blowing arc arc extinguish chamber,under the condition of the iron core is magnetized arc at the same time,using the principle of magnetic blow,The arc blow into the arcing chamber,in the heart of the arcing chamber arc extinguishing,through the calculation and simulation,the sealing structure of the double breakpoint contact circuit breaker box,completely can achieve higher breaking capacity,short-circuit breaking through the test results can be seen that breaking current in a circuit breaker,realize fast breaking around 5 ms,limited current continue to increase,in the gas blow and blow,under the dual function of magnetic arc extinguish quickly,so as to realize the high score of 150 ka fault levels.Through the double verification of analysis and test data,it is shown that the double breakpoint structure plays an important role in the fast breaking and current limiting,and the air and magnetic blowing structure plays an important role in the fast extinguishing of arc.In addition,double breakpoint molded case circuit breakers are oriented to high-end customer groups,in the product design precision and strength are relatively high,can ensure the high reliable operation of the switch,fully meet the needs of a variety of complex application environment.