Abstract The main objective of this two parts state of the art paper called 'Recent Advances in the Design, Modeling and Control of Multiphase Machines' is to present latest contributions in the multiphase machines' field. The first part of the work focuses on the recent progress in the design, modelling and control while the drive is in healthy operation. This second part presents relevant contributions in two not analyzed fields. The first is in relation with the use of the additional degrees of freedom of multiphase machines and the exploitation of their fault-tolerant capabilities without adding extra hardware. The second one analyzes multiphase generation, especially in grid-connected wind energy conversion systems and stand-alone applications. Recent progresses are shown and open challenges and future research directions are discussed.Index Terms Multiphase machines, motor drive control in faulty operation modes, generation systems. Manuscript

Abstract Multiphase machines are well recognized as an attractive alternative to conventional three-phase ones in a number of applications where high overall system reliability and reduction in the total power per phase are required. The pace of developments in the field has accelerated in the last few years, and substantial knowledge has been recently generated. The main objective of the two parts' survey named 'Recent Advances in the Design, Modeling and Control of Multiphase Machines' is to present relevant contributions to encourage and guide new advances and developments in the field. More specifically, the part 1 of the work analyzes the recent progress in the design, modelling and control, including healthy operation of multiphase motor drives, and discusses open challenges and future research directions in the area.Index Terms Multiphase machines, design, modeling, parameter estimation, motor drive control in normal operation mode. Manuscript

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The fault tolerance of electric drives is highly appreciated at industry for security and economic reasons, and the inherent redundancy of six-phase machines provides the desired fault-tolerant capability with no extra hardware. For this reason some recent research efforts have been focused on the fault-tolerant design, modelling and control of six-phase machines. Nevertheless, a unified and conclusive analysis of the post-fault capability of six-phase machine is still missing. This work provides a full picture of the post-fault derating in generic six-phase machines and a specific analysis of the faulttolerant capability of the three mainstream six-phase induction machines (asymmetrical, symmetrical and dual three-phase). Experimental results confirm the theoretical post-fault current limits and allow concluding which is the best six-phase machine for each fault scenario and neutral arrangement.Index Terms Six-phase drives, fault-tolerance, field oriented control.

Abstract One of the most attractive features of multiphase machines is the fault-tolerant capability due to the higher number of phases. Different post-fault control strategies based on hysteresis, PI-resonant and predictive techniques have been recently proposed. They all proved their capabilities to withstand fault situations and to preserve the fundamental component of the air-gap field, while achieving minimum losses, maximum torque per-ampere and reducing torque vibrations. Nonetheless, due to their recent introduction, no thorough study has yet appeared comparing the performance of these controllers. In this paper two open-phase fault-tolerant control schemes are experimentally compared in a real five-phase induction machine. The controllers being compared are based on PI-resonant and predictive control techniques, respectively. The experiments include pre-and postfault situations. Obtained results show that both control methods offer nearly the same performance. When compared, predictive control provides faster control response and superior performance at low speed operation but is found to be less resilient to fault detection delays and to have higher current ripple. Regarding the controller implementation, it is shown that the transition from preto post-fault operation involves modelling the non-linear effects observed when an open-phase fault occurs for the predictive controller, and the proper retuning of the PI trackers for the PIresonant controller, in order to ensure post-fault operation.