A sensorless hybrid control strategy for induction motors in aerospace applications

In aerospace applications, electric pumps and steering motors operate within highly congested electromagnetic environments. Cross-interference among densely packed electronic equipment induces erroneous readings in position sensors. Consequently, sensorless control schemes have gained substantial prominence for their inherent robustness. However the pivotal procedure of control strategy—flux observer exhibits severe degradation in estimation accuracy when subjected to electromagnetic interference (EMI) and low-speed operation，which may destabilize the control system.Conventional solutions often require complex speed compensation strategies whose performance heavily depends on specific motor parameters, resulting in limited versatility . This paper proposes a novel composite control strategy based on the improved I/F control start-up and then smoothing the transition to sensorless vector control. The method achieves stable operation during the entire speed range without requiring speed information, combining algorithmic simplicity with strong versatility. Theoretical analysis of the I/F control’s low-speed stability is first analysed. Subsequently, the stator-current-based MRAS method is introduced, and transition strategy is designed .Finally the strategy’s effectiveness is verified by simulations and experiments on an induct ion motor.