IRFO-Based Ride-Through Control of a Dual-Stator Induction Motor (MACU) under Voltage Unbalance: Modeling and Experimental Validation

Voltage unbalance and phase loss are common disturbances in weakly interconnected power systems and significantly degrade the performance of induction motor drives. This paper proposes a fault-tolerant solution based on a Universal Cage Induction Motor (MACU) featuring a dual-stator architecture composed of a main three-phase winding and an auxiliary single-phase winding. This configuration introduces magnetic redundancy, enabling the preservation of rotor flux under severe unbalanced supply conditions. A comprehensive electromagnetic model of the MACU is developed in the rotating $\left(dq\right)$ reference frame, accounting for stator coupling, capacitor effects, and symmetrical component interactions under unbalance. An IRFO (Indirect Rotor Field Orientation)-based control strategy is implemented to regulate flux and torque, including an automatic ride-through mechanism enabling transition from three-phase to single-phase operation. Simulation and experimental validation on a dedicated test bench show that the proposed system maintains operation under high unbalance levels (up to $k_U\approx 80\text{\%}$ ), with rotor flux deviation below 3% and mechanical speed variation below 2.7% during transitions. The comparison between simulation and measurements indicates deviations below 3% for key variables. These results indicate that the MACU combined with IRFO control provides a fault-tolerant drive solution with reduced structural complexity compared to multiphase architectures, while maintaining stable operation under severe grid disturbances.