Design of electromagnetic force driving actuator (EMFA) and linkage for molded case circuit breaker

With the recent increase in social demand for ´Power IT´, a dire need for electrical equipment capable of remote control, such as measuring, communication, etc., has arisen. Therefore, this paper shows that molded case circuit breaker (MCCB), which is a typical electrical equipment widely used in low-voltage circuits, can be miniaturized and remotely controlled by adapting electromagnetic force driving actuator (EMFA). EMFA is a driving device operated by electromagnetic force generated from permanent magnets and electric current. The 2-D finite element method (FEM) and the time difference method (TDM) were employed in analysis of magnetic field and dynamic characteristics during the design process of EMFA. In order to adapt EMFA into MCCB, linkage system connecting each other was devised considering the load of interrupter portion and the holding force of actuator.