Dynamic Simulation of Mini circuit breaker

Because the breaking characteristics of contacts decide the reliability of miniature breaker, it is necessary to study it. In this paper, the mathematic theory is firstly elaborate. And the 3D model of contacts is built after that. Based on virtual prototyping technology, the breaking characteristic in different short circuit current is obtained by use of ADAMS. Overview Miniature circuit breaker is a key component in low voltage distribution network. It could break the fault current based on the work performance of devices. It could protect the grid and prevent the fault expanding . With economic development, increasing demand for power generation capacity, distribution system reliability has become even more important, so that further action features and protection MCB put forward higher requirements. As a molded case circuit breaker, although small, but its structure and working principle is not simple, especially short-circuit breaking MCB process is extremely complex. Therefore, this paper uses software to explore the contact performance in short-circuit breaking. Math Model The internal structure of miniature circuit breaker is complex, and the inner force on the structure is changing with the short circuit current. Hence, the general method is difficult to study the dynamics . This paper uses the current design and manufacturing areas of new technology virtual prototyping technology to multi-body dynamics simulation software ADAMS as a platform for small circuit breaker contacts dynamics simulation. Generalized coordinates are Cartesian coordinates of the centroid and the reaction rigid rigid orientation Euler angles i ADAMS software in the composition, i.e., qi=[x,y,z,Ψ,θ,Φ]i,q=[q1...qn]. Lagrange multiplier method to establish the system equations of motion: T T T T q q d T T f g Q dt q q ρ μ     ∂ ∂ − + + =     ∂ ∂     