Model-based synchronous machine control with compensation of model inaccuracies and instantaneous flux weakening capabilities

This paper proposes a model-based current/torque control strategy for synchronous machines, where the magnetic model mismatches are compensated in real time and the flux weakening operation is obtained without the need of an external voltage regulation loop. Starting from an initial (and potentially wrong) knowledge of the non-linear current-to-flux linkage relation in the form of a look-up-table, a combination of feedforward actions, compensating mechanisms and binary searches are used to achieve the target during real-time operation. The algorithm is implemented in a laboratory test bench and successfully verified with experiments on an 11-kW synchronous reluctance machine, proving the feasibility of the proposed approach.