塑壳断路器触头分断速度定量计算方法的研究

Study on breaking action characteristics of moulded case circuit-breaker contact

针对塑壳断路器触头分断速度计算难的问题,提出了一种定量计算触头分断速度的方法.该方法分析了解扣后触头机构各杆件的实际受力情况和运动关系,利用质点系动能原理,以等效杆代替触头连杆机构,结合微分方法精确地计算出触头分断过程中各杆件的角位移、角速度关系式,以及机构等效转动惯量、等效力矩,并求解出触头分断速度.结果表明,以DZ20J-100塑壳断路器为实例计算得到的触头分断速度和分断时间与试验结果基本相符,验证了算法的正确性.

Aimed at the difficulty of calculating moulded case circuit-breaker contact breaking speed, a quantitative arithmetic method was proposed. Pressure distribution and movement relationship of bars were analyzed in the method when the contact device was separated, and the kinetic energy theorem of particles system was introduced to replace contact device with equivalent bars. After the relation expressions of angle movement and angle speed were deduced combining with differentiation method, the equivalent moment of inertia and equivalent moment of the device were obtained, and the contact breaking speed was calculated. Results show that breaking speed and breaking time of the contact calculated by the method are basically equal to experimental results by using DZ20J-100 moulded case circuit-breaker as example, and validity of the method is proved.