Strategie avanzate di diagnostica e controllo per azionamenti elettrici trifase e multifase

The increasing demand for variable speed motors that offer high-performance and high-power has led to a significant increase in the research on multiphase machines over the past two decades. Indeed, one of the primary benefits of multiphase technology is the possibility to split the power among a greater number of lower-rated power electronic components. Furthermore, a greater number of phases corresponds to an higher number of degrees of freedom, which can be utilized for purposes such as fault diagnosis and to increase the machine torque density. A great part of the thesis work focuses on modeling faulty three-phase and multiphase electrical machines along with the utilization of Artificial Intelligence (AI) techniques for accurately identify and distinguish various types of failures. The failures studied comprises manufacturing defects, high-resistance connections, and inter-turn short circuits. The approaches presented in the thesis exhibit extensive applicability for surface-mounted permanent magnet synchronous motors but can be extended to different electrical machines types. An investigation was conducted on the control of two-level multiphase voltage source inverters. A control strategy was developed for reducing the root mean square of the output current ripple produced by multiphase inverters with an odd number of phases. Furthermore, the frequency of commutations of the power electronic components is reduced. All the investigations have been assessed through simulations and experimental tests employing prototypes of three-phase and multiphase electric drives.