Design And Research Of A High Power Contactor

In order to meet the power requirement, energy supply in electrical-vehicle and aircraft is transferring to high voltages. This change brings the advantage of less cable size and weight. However the introduction of High DC voltages have led to a growing demand to the swithing or protecting contactors, such as high power interrupt, long life and so on. Thus a 270V/200 A load hermetically sealed high voltage contactor was designed and the character of mechanical environment and electrical life were experimented.Firstly, contact system's scheme was designed on basis of the rule of brige contact under transverse permanent magnetic field. Through an experiment equipment which can simulate breaking process of contactor, the arc extinguish experiment were carried out vary from contact stucture,contact material, flux density of TMF, atmosphere pressure.Thus the key parameters including open velocity, contact gap,over travel, flux density of transverse permanent magnetic field were obtained.Secondly, using finite element software Maxswell, the 3D finite element model of the contactor's electromagnet was built. The static characteristics of the electromagnet was simulated. Further, based on the static magnetic force sheet and static magnetic flux sheet, the unite simulation model of Matlab-Adams was established, the dynamic characteristics is simulated. By assembling physical model and carring static and dynamic characteristic testing,the result of simulation was confirmed.Finally, several prototypes were manufactured. The parameters of part size,mechanical force,electrical performace,environmental endurance and life performance were experimented.The failure mode and mechanism were analysed. The mechanism of permanent magnetic material and flux density acting on contact life were gaved,as well as the rule of open velocity,over travel and contact force acting on contact life were researched.The results of mechanical environment test and electrical life test indicated the general performance of this contact has meet the level of Tyco's.contactor LEV200.