다물체 동역학 해석 기법을 이용한 고압회로 차단기용 코일스프링의 최적설계

Abstract

Since the performance of a circuit breaker which has the spring operating mechanism mainly depends on the dynamic behavior of a coil spring, the analysis of the dynamic behavior of a coil spring is required for a performance evaluation of a circuit breaker. Since a large load spring moves with large acceleration, the mass effect of a spring is considered significantly. When a spring moves so fast from the releasing state, a lot of energy is used to move a self-weight of a spring. For that reason, the energy stored by compression of a spring is not all transferred to the follower. Thus, the analysis of the mass effect of a spring during high-speed motion is required for the performance evaluation of a circuit breaker accurately. In this study, a release test bed is designed for evaluating the dynamic behaviors of a coil spring. From the release tests, the dynamic behaviors of a coil spring are analyzed. Three types of spring models such as a linear spring model, a nodal spring model and a lumped parameter spring model are established for comparing the modeling error of a spring due to the mass effect. RecurDyn is employed to carry out the computer simulation and results are compared with test results. The actual energy transferred to the follower during high-speed motion is analyzed through the comparisons of the kinetic energy between the experiment and the computer simulation. The design variables of a coil-spring are optimized by using design of experiments(DOE) based optimization method. According to this result, the release velocity of the spring is increased by 2.90% and the energy transfer efficiency is increased by 2.60%.