Multi-phase Induction Machine Speed Estimation Method Using Rotor Slot Harmonics

Multi-phase machines are becoming more popular due to their good performances and are progressively suppressing classical three-phase machines in some applications. Additionally, sensorless control of electrical machines has been thoroughly investigated in the last decades in order to lower the costs associated with the speed sensors used in electrical drives and increase the reliability of the drive. In the literature, rotor slot harmonics were intensively inspected to obtain information about rotor speed and position. In this paper, a speed estimation technique based on rotor slot harmonics in a multi-phase induction machine was proposed, based on the familiar approaches. It relies on the spectral analysis of the stator current. The most important benefit of the method introduced in the paper is lack of any type of the filter for extracting the specific rotor slot harmonics from the current spectrum. Simulation results that verify the effectiveness of the method proposed were obtained using MATLAB/Simulink.