An Efficient Field-Circuit Coupling Based on a Temporary Linearization of FE Electrical Machine Models

A field-circuit coupling method is presented, whose basic idea is to extract from the finite-element (FE) model a linearized lumped parameter representation of the electrical machines, to be used in the circuit simulator model of the power electronic supply. The dynamic coupled model of the complete drive obtained this way can be iterated over a limited period of time, with a time step adapted to the high frequency of electronic commutations. When the temporary representation of the machine has come, or is expected to have come under a given accuracy threshold, a new FE simulation is performed, a new set of lumped is generated and the process is repeated. This method allows decoupling the time constants of the field problem from that of the circuit problem, which is typically one or two orders of magnitude smaller. This yields a considerable saving of computation time with a controllable, at least a posteriori, loss of accuracy.