A study on dynamic behavior of multibody dynamics model on ring main unit

Ring Main Unit(RMU) are now widely used to protect MV/LV transformers as well as construct Loop distribution system. It uses SF6 gas for insulation and therefore it can possible to make compact switchgear and maintenance free due to tightness tank structure. It consists of Load Break Switch(LBS), Fuse combination switch and Circuit Breaker(CB) including Vacuum Interrupter(VI). Especially, a RMU using CB function for MV, which is used in a power plant for renewable energy, requires very large contact spring force because it has to be able to withstand the high short circuit current. In this study, the RMU CB module sample has been designed and its analytical multibody dynamic model using an dynamic simulator(CREO MDO) has been developed. To find out the necessary design variables of RMU, the result values of analytical model are used. Thus the RMU CB module sample has been manufactured and measured for dynamic characteristic to compare with the analytical model.