A robust sensor-less field-oriented control of six-phase induction motor drive with reduced common mode voltage

This article narrates a robust sensor-less indirect rotor field-oriented control (IRFOC) of a six-phase asymmetrical induction motor (SPAIM) drive with an online estimation of parameters and reduction of common mode voltage (CMV). In comparison to the conventional IRFOC technique, the proposed IRFOC provides the least CMV using modified space vector modulation (SVM). To guarantee proper operation of IRFOC, accurate estimation of rotor time constant is mandatory; any mismatch in the actual and tuned value may lead to poor performance of the IRFOC algorithm. This problem will be further accelerated with encoder-less control using model-based estimators. In this manuscript, the problem of simultaneous estimation of speed and machine parameters is investigated, and a model reference adaptive system (MRAS) based speed estimator accompanied by online estimation of parameters is proposed to improve sturdiness against variation of parameters. A Simulink model of the proposed method is developed and a simulation study is carried out. To validate the simulation results, a scaled prototype model of The SPAIM rated for 2 HP, 200 V is developed and encoder-less IRFOC for the SPAIM drives is implemented using an STM32F407VG controller board. The performance of the proposed observers is tested and verified for all the possible operating conditions and results are presented. This article describes the robust encoder-less field-oriented control (FOC) of a six-phase asymmetrical induction motor (SPAIM) drive with reduced common mode voltage. The sensor-less control of the SPAIM drive is achieved using rotor flux-based MRAS (RF-MRAS). The operation of FOC and RF-MRAS is affected by the variations in the parameters of the induction motor drive such as the time constant of the rotor and stator resistance. Therefore, the online estimation of rotor time constant and stator resistance is also included to improve the robustness of the drive system. Further, a reduction in the common mode voltage is achieved using a modified switching vector-based space vector modulation technique. image