Phase-Domain Model

For the simulation of electrical machines and drive systems,  the abc-model brings benefits in terms of accuracy, efficiency and flexibility. In particular, it allows one to naturally include both geometry- and saturation-induced space harmonics. We propose here a novel nonlinear abc-model using current-flux linkage and electromagnetic torque N-D lookup tables. The current-flux linkage lookup tables are built from the flux linkage-current lookup tables using inversion and N-D interpolation. The abc-model is validated by comparison with the circuit-coupled finite  element  model, in both steady and transient state, for balanced and unbalanced operation. It gives the same results as the finite element model with a speedup factor of about two orders of magnitude.

For the dynamic simulation of rotating electrical machines, the phase-domain model brings many advantages in terms of accuracy, efficiency and flexibility. In particular, it allows one to naturally take into account space harmonics and saturation. We discuss here the implementation of the phase-domain model with lookup tables for both the linear and nonlinear cases. First, we compare various implementations of the linear phase-domain model with the classical dq-model. In addition, we examine the execution time and the error introduced by the lookup tables. Then, we propose a simple implementation of the nonlinear phase-domain model using a N-dimensional lookup table representing the winding currents as functions of the rotor angle and the winding flux linkages. We show how to obtain this table from the flux linkage-current relationship. Finally, we compare the nonlinear phase-domain results with the finite element model.