Sensorless Control of a Stand-Alone Five-phase Doubly Fed Induction Generator

This paper proposes a sensorless control system for a multiphase doubly-fed induction generator MDFIG. The simplified adaptive observer was proposed to reconstruct the speed and rotor position. The control system is based on a classical mathematical model and the stator field-oriented control method. Compared to the traditional double-fed induction generator, the MDFIG has increased reliability, reduced current level per phase, and low rotor harmonic currents. For the wind turbine system, the control system has been extended for dedicated 5-phase operation, and additional scenarios have been added. The dynamic states of the generator operation under normal operating conditions with voltage variation and load were simulated and compared with laboratory tests. The fault-tolerance results of rotor phase failures with different states and loads were presented. This performance is validated in the laboratory with a 2 kW prototype five-phase DFIG system.