Sensorless Field-Oriented Control of a Low-Speed Six-Phase Induction Generator

This paper presents a sensorless control strategy for a six-phase induction generator (6PIG) operating at low speed (125 rpm). The proposed approach is based on the Model Reference Adaptive System (MRAS), with an initial estimation scheme developed using the reference model as the rotor flux. Simulation studies were conducted in MATLAB/Simulink 24.2.0.2740171 (R2024b) Update 1 and experimentally validated on a 24 kW–125 rpm 6PIG, to demonstrate the feasibility and performance of this method. A reactive power-based MRAS variant was also proposed to overcome the observed limitations. Comparative analysis showed a significant improvement in estimation accuracy and dynamic response compared with the flux-based MRAS. Robustness tests under fault conditions, such as opening phases, confirmed that the reactive power-based MRAS maintains a stable and accurate rotor speed estimation. These findings demonstrate the potential of reactive-power-based MRAS for the sensorless control of six-phase induction generators (6PIGs) in renewable energy systems.