Characteristic analysis and design of a novel permanent magnetic actuator for a vacuum circuit breaker

In this study, a novel permanent magnetic actuator (PMA) termed a separated permanent magnetic actuator (SPMA) is proposed. The efficiency of the proposed SPMA is significantly higher than a conventional PMA because of its innovative structure, with which the magnetic flux path is efficient and the holding forces can be designed independently taking the unique values of each load into consideration. Hence, the SPMA is smaller in size and lower in cost than the conventional PMA. For the SPMA, a characteristic analysis and design method using a two-dimensional finite element method, an equivalent circuit, an equation of motion and a time difference method is suggested in this study to save time and reduce the costs incurred because of the experimental trial and error deign. The SPMA was designed and prototyped such that the usefulness of the SPMA for application to a vacuum circuit breaker and the reasonableness of the suggested characteristic analysis and design method were confirmed by the experimental data.