Circuit coupled simulation of a claw-pole alternator by a temporary linearization of the 3D-FE model

During the final stage in the design of electrical machines adequate models are required to predict the behavior at given points of operation. Due to its irreducible 3D flux path structure and the connected bridge rectifier, the claw pole generator is a challenging field-circuit coupled system. It can be solved either by permeance models, state space models or numerically strong coupled formulations within a Finite Element Analysis (FEA). Alternatively, a numerically weakly coupled method is presented in this paper. A temporary lumped parameter representation of the alternator seen from stator terminals is extracted from the Jacobian matrix of the linearized FE model. This lumped parameter representation of the machine is then incorporated into a circuit simulator based on the modified nodal analysis (MNA).