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This paper investigates a real-time fault diagnostic of a transportation system which needs two drives with fault-tolerance capabilities. Because of constraints on the mass of the system and on the cost of the Voltage Source Inverter (VSI), a drive with two Six-Phase Permanent Magnet Synchronous Machines (PMSM) in series-connection supplied by two six-leg inverters is chosen. Despite the serial -connection, independent control of the two machines and fault –tolerance to open-switch fault is ensured. Nevertheless, a Fault Detection Identification (FDI) process is required for analysis and/or control reconfiguration. The proposed FDI is based on the combination of different criteria obtained from the two zero-sequence currents and from the normalized currents mapped into two frames defined by the Concordia Transformation. Results obtained from simulation and experimental tests show the effectiveness of the proposal.

This paper studies the electromagnetic noise behaviour of a 5 phase Interior Permanent Magnet Machine with fractional slot concentrated winding designed. A numerical model is used for analysing the torque characteristics and electromagnetic forces. The vibro-acoustics and mechanical resonance of the model are then investigated analytically. The purpose of both analyses is to identify the source of electromagnetic noise within the machine. A sonogram is also carried out on the existing prototype to correlate it with the numerical results. Finally, the choice of the appropriate method to attenuate noise for this case study is elaborated.

In the context of future Permanent Magnet Synchronous Machines (PMSMs) with a high number of phases (>7) in integrated drives, this paper proposes several control strategies when multiphase PMSMs with non-sinusoidal back electromotive forces (back-EMFs) operate in healthy and open-circuit faults. In all operation modes, the considered constraint on current is related to the maximum root mean square (RMS) current allowable in one phase of the machine. The constraint on voltage limits the maximum peak value of the phase voltage determined by the DC-bus voltage of the converter. When one or two phases are open-circuited, to maximize torque and respect the constraints, new current references obtained by several proposed methods in rotating and natural frames are imposed to the machine. Due to the non-sinusoidal waveform of back-EMFs and the considered constraints, numerical computations based on analytical formulations are required to obtain maximal torque-speed characteristics, including the flux-weakening operation. The usefulness of the proposed strategies is verified by numerical and experimental results.

This paper proposes several easy-to-implement control strategies when seven-phase axial flux brushless DC machines with trapezoidal back electromotive forces operate in normal and faulty modes by taking into account constraints on voltage and current. The constraints are related to the converter and machine design in terms of maximum values of current and voltage. The considered faults are cases in which one or two phases of the machine are open-circuited. Numerical computations based on analytical formulations are applied to obtain torque-speed characteristics, including the flux-weakening operation. The methods determine current references to ensure the torque optimizations while currents and voltages are within their limits. The usefulness of the methods is verified by numerical results.

High cost, no-ideal driving range and charge time limit electric vehicle market share. Facing these challenges, an integrated motor drive/battery charger system has been proposed by Valeo. A further advancement, based on this system, is present in this paper; for the first time, the integration of traction, charging and air-compressor supply modes is proposed and tested by real-time experimentation. This integrated system is expected to increase the vehicle component compactness and power, therefore potentially reduce the cost and battery charging time. An overall and unique control scheme is detailed to achieve the three main operating modes: traction, charging and air-compressor supply modes. The real-time experimentation results show the system feasibility.

This paper presents an extension of previous methods in order to find electrical series-connections between multiphase machines allowing the independent control of each one of them. These new electrical series-connections explore the symmetrical disposition of the phases of even-multiphase machines, allowing the inversed connection of some of the phases, different from the direct connections as it was previously done. Therefore, electrical series-connections of two symmetrical 6-phase or of four symmetrical 10-phase machines are now possible. Besides that, this new solution ensures a natural independent control of permanent magnet synchronous machines even if the back-electromotive forces generated by the rotor are not sinusoidal, without need of special machine conception or supplementary control strategy. This control independency is mathematically proved using the decomposition of multiphase machines in fictitious diphase and homopolar machines. Experimental results are presented to show the functioning and the advantages of this new coupling for two symmetrical 6-phase permanent magnet synchronous machines.

This paper analyzes two fault-tolerant dual-multiphase motor drives, a series connected topology and a standard H-bridge topology. Previous studies have shown that the series connected topology is appropriate to an aerospace application and has lower peak current in degraded mode in comparison with the H-bridge topology, which may consequently diminish the system’s weight and cost. This paper extends the study to compare different control strategies of these structures under two fault conditions: short-circuit of an inverter’s switch and an open-phase of the machine. The control strategies analyzed in this paper do not impact the fundamental current or the torque generation, but the amplitudes of some harmonics in degraded mode are expected to be narrowed down in order to reduce the inverter’s size. Some analyses of maximum voltage and peak current in degraded mode have been used for inverter dimensioning. Experimental results are shown and compared to the simulated ones to confirm the validity of this study.

Torque density is usually improved by injecting the third current harmonic for five-phase permanent magnet synchronous machine (PMSM). It increases the degrees of freedom of a multiphase drive. However, it also separates the current limitations of the motor and the transistors, respectively related to the RMS and peak values of the currents. These two constraints are represented by Maximum Torque Per Ampere (MTPA) strategy and Maximum Torque Per Peak Current (MTPPC) strategy. In this paper, these two strategies are studied and analyzed in order to optimize the generated torque with injection of the third current harmonic. Torque improvement principal and the optimizing algorithm considering two constraints are illustrated. Then, the analytical results of these two strategies are compared and discussed. It is shown that injecting the third current harmonic can improve the torque especially at flux-weakening region. Besides, compared with MTPA, MTPPC could produce higher torque for the same inverter current limit.

This paper presents new fault-tolerant control strategies for field-oriented control of 7-phase non-sinusoidal permanent magnet (PM) machines supplied by voltage source inverters (VSI). Single phase open-circuit fault is considered. The proposed strategies aim at finding waveforms of current references in natural frame in the way that post-fault currents create the same rotational magnetomotive force (MMF) as in healthy mode. Therefore, in the faulty mode, average torque can be maintained if no current limits are set. The proposed strategies are validated and compared to a previous strategy by numerical results in terms of joule losses, maximum RMS and peak phase currents, maximum phase voltage as well as their controllability with PI controllers.

For an open-end windings integrated Permanent Magnet Synchronous Machine, the demagnetization of the permanent magnets is analyzed when a transistor is shortcircuited and no specific control strategy is adopted. Depending on the temperature, the high currents due to the inverter fault may locally demagnetized the permanent magnets leading to an accelerated aging of the machine and torque loss. A cosimulation, using a Finite Element software for the machine coupled with an average modeling of the transistor, gives interesting local prediction of the machine behavior in healthy and degraded mode.

Compared to sinusoidal machines, a bi-harmonic machine (with only two harmonics of similar value in the electromotive force spectrum) can develop torque of comparable values under three kinds of supply: with only first or both first and third sinusoidal currents. Therefore, more degrees of freedom for the control of the machine can be achieved. In this paper, the specificities of 7-phase bi-harmonic permanent magnet synchronous machine (PMSM) are investigated under different control strategies, such as maximum torque per ampere (MTPA) at low speed and fluxweakening strategies at high speed, both in healthy and faulty operation modes. The fault with one open-circuited phase are taken into account. The current references are calculated in order to maximize the output torque under the constraint on both voltage and current. The performances of the considered machine is validated by numerical results.

This paper studies the electromagnetic noise behaviour of a 5 phase Interior Permanent Magnet Machine with fractional slot concentrated winding designed. A numerical model is used for analysing the torque characteristics and electromagnetic forces. The vibro-acoustics and mechanical resonance of the model are then investigated analytically. The purpose of both analyses is to identify the source of electromagnetic noise within the machine. A sonogram is also carried out on the existing prototype to correlate it with the numerical results. Finally, the choice of the appropriate method to attenuate noise for this case study is elaborated.

This paper analyses the copper losses due to the homopolar current of a five-phase open-end winding machine supplied by a 10-leg inverter and a single DC voltage source. This topology can have non-null high frequency homopolar current components that can increase the machine’s copper losses and result in overheating of the motor phase windings, a special concern for integrated drives. Accordingly, different modulation strategies are compared with the goal of reducing the homopolar current and, consequently the relative copper losses. The comparison study is achieved using Matlab/Simulink and a finite elements model in order to evaluate these losses.

This paper deals with the fault effects analysis and diagnosis in 6-Φ PMSM designed for aerospace applications. The addressed work aims to analyze the features offered by the space vector theory applied to these systems for fault detection and identification purposes. The paper starts with a presentation of the overall electric drive system structure and its control. Then, fault effects analysis under faulty operation mode of the 6-leg voltage source inverter is presented considering the space vector theory. Based on such analysis, an accurate FDI process is designed for these applications. All results are verified analytically and through simulation software using Matlab/Simulink

This paper analyzes two dual-motor fault-tolerant topologies. The first one supplies independently both machines while the second one connects them in series for reducing the number of transistors. For a given DC-link voltage, the converter component sizing is based on the peak current obtained in the normal and degraded modes.

This paper analyzes two dual-motor fault-tolerant topologies for aerospace thruster application.The first structure supplies independently both machines whilethe second one connects them in seriesfor reducing the number of transistors and offering a capability of energy management between the sources. Inverter short-circuit fault isconsidered.Based on the peak-currents obtained in simulation in degraded mode without reconfiguration and with two different reconfiguration strategies, the two proposed topologies can be compared in economic and technical aspects.

Dans le cadre d’une commande en mode dégradé d’un drive comprenant deux machines polyphasées connectées en série et pilotées de façon indépendantes, l’article s’intéresse à analyser la performance du drive dans le cas d’une reconfiguration complète, c’est-à-dire, une modification de l’algorithme de commande lors d’un défaut en mode dégradé

Dans les avions et lanceurs, des systèmes entraînés par l’énergie hydraulique, mécanique ou pneumatique sont progressivement remplacés par des systèmes électriques pour des raisons techniques et industrielles. Cependant, ces nouveaux systèmes doivent répondre aux contraintes économiques et de poids concernant ces domaines tout en garantissant une certaine fiabilité. Dans ce contexte industriel, des topologies innovantes multi-machines multi-convertisseurs à haut niveau de fiabilité sont comparées ici à des structures plus standards toujours tolérantes aux défaillances. Ainsi, des topologies avec des machines polyphasées couplées électriquement en série ont été choisies pour ce travail de thèse. La mise en série permet la mutualisation des bras d’onduleurs, réduisant ainsi leur nombre, et augmente la résistance totale du système. La valeur crête du courant est alors réduite lors de l’apparition de certains défauts avec, comme contrepartie, une augmentation inéluctable des pertes Joule globales. Pour que le contrôle de ces machines couplées électriquement en série soit indépendant, il est mis en évidence pourquoi le nombre de phase de ces machines doit être supérieur à 3 et avec de plus une connexion électrique spéciale permutant les phases. Une nouvelle topologie brevetée est tout particulièrement étudiée et testée expérimentalement. Apres validation du concept, des stratégies de contrôle plus complexes et des reconfigurations de la commande après le défaut sont appliquées afin de juger des potentialités d’amélioration du système. Pour les comparaisons, des simulations et des essais expérimentaux ont été réalisés. Les critères choisis pour cette comparaison ont été la puissance de dimensionnement de l’onduleur, servant d’image de son coût et de son poids, les pertes Joule et le couple pulsatoire, tous les trois pour un fonctionnement en mode dégradé.