A Robust Simplified Dynamic Observer-Based Backstepping Control of Six-Phase Induction Motor for Marine Vessels Applications

This paper presents a robust simplified dynamic observer-based backstepping control (RSDO-BSC) of a six-phase induction motor (6PIM) for marine vessels applications. First, both the flux and the torque are decoupled using Lyapunov's theory on a 6PIM 2-axis mathematical model represented in the stationary reference frame. The 6PIM actual stator voltages are acquired from the DC-link voltage via the space vector pulsewidth modulated (SVPWM) inverter. Subsequently, when the 6PIM is loaded under the rated rotor speed, a rapid search approach is used to maximize the efficiency of the 6PIM. In this approach, the rotor flux command is reduced gradually until the mean of real input power to the 6PIM converges to a minimal value. Furthermore, the proposed RSDO-BSC design is used to estimate the 6PIM rotor angular speed online. A 750-W 6PIM drive test setup employs a dSPACE 1104 for real-time implementation. The performance of the proposed RSDO-BSC is experimentally investigated during load disturbance, different reference speed, low speed command and low load torque conditions.