A finite element method for transient analysis of power electronic motor drives including parasitic capacitive effect and external circuit

A two dimensional (2-D) finite element method (FEM) of transient electromagnetic field for modeling power electronic motor drives is presented. The proposed method takes into account the parasitic capacitive effect and can be coupled with arbitrarily connected circuits. The FEM formulation which includes the displacement current in the direction of the modelpsilas depth is deduced. The displacement current effect in the plane of the solution domain is represented by coupling the circuit of capacitances into the FEM equations. By introducing additional unknowns, the final set of the system equations has a symmetrical coefficient matrix. A method using electric charge as an excitation for the computation of the capacitance matrix is also proposed for reducing the computation time. The developed algorithm has been applied to simulate systems with power sources having high frequency and/or high dv/dt.