A Fully Coupled Framework And Experiments Of Electromagnetic Operating Mechanism In Low-voltage Apparatus

As a new type of virtual development technology, computer visual simulation technology, has gradually become an important method for the design and development of low-voltage electrical apparatus insteading of the traditional test method of making prototype repeatedly. Many researches haven been performed on low-voltage electrical simulation technique and the proposed methods can predict the dynamic characteristics of the electromagnetic operating mechanism of low-voltage electrical apparatus conditionally. However, there are too many assumptions and simplification in these methods, and the methods cannot perform calculation of different physical fields synchronously.In this thesis, a multibody dynamics method based on continuum mechanics and a electro-magneto-mechanical coupling method are developed to predict the dynamic characteristics of the circuit breakers and the permanent magnet (PM) contactors. The methods can effectively solve the problems in the old methods, and can improve the simulation and digital design technology of low-voltage electrical apparatus.The proposed methods are demonstrated by contrasting the results of simulation and experiment. Firstly, the 3D virtual models of the electromagnetic operating mechanisms are established with material,mechanical and electromagnetic properties in the software, and the models are applied with constraints and controlling equations to form a complete virtual prototype. The dynamic characteristics and 3D distribution plots of different variables in the model are predicted by calculation.Secondly, the experimental platforms are designed and established to measure the dynamic characteristics of the physical prototypes, including the measurement of the motion and stress of the circuit breaker, and the measurement of the motion and electromagnetic characteristics of the contactor. In this thesis, a non-contact measurement method is designed to measure the displacement and velocity of the mechanisms with no negative influence to the operation of the prototypes.Finally, the simulation results are compared with the experimental results, and the correctness and reliability of the simulation method are verified by analyzing the similarity of the simulation and experimental results. Physical measurements show that the dynamic process of the prototypes can be captured by the the models with good precision. The proposed methods provides a new guidance to improve the mechanical reliability and the design level of circuit breakers and contactors.