High frequency modeling of synchronous magnet machines, Application to the early detection of inter-turn fault and demagnetization fault

Powertrain electrification in the transportation field is currently a strong trend. Permanent magnet synchronous machines (PMSM) are commonly used in this type of application because of their compact design and their high energy efficiency. In this context, the proposed PhD thesis concerns the detection of defects in PMSM right from their first appearance phase in order to plan maintenance time, to reduce repair cost and to increase machine availability. The presence of defects also affects the machine productivity, thus early fault detection helps in reducing energy losses and increases the cycle efficiency of on-board energy conversion systems. Two of the most critical faults are the insulation breakdown between two turns of the stator winding and the rotor demagnetization fault. The proposed PhD thesis focuses on the early detection of these two defects based on the high frequency (HF) behavior of these machines against a HF excitation. The interest of this study is to take into account the imbalances introduced by the appearance of faults in order to detect their presence as soon as possible. To achieve these goals, this PhD thesis proposal requires several challenges. The first is to develop experimental HF stator/rotor models which are representative of the PMSM behavior following a HF excitation. The second is to develop diagnostic methods, associated with the developed models, capable of differentiating a fault state from a normal one depending on the operating conditions of the studied system. The third challenge is to experimentally validate the fault detection methods on a test bench using injections of high frequency signals.

Keywords: electric machine modeling, diagnosis, aging monitoring, fault detection, early faults, inter-turn faults, demagnetization fault, high frequency excitation.

• Academic supervisor    Professor, MEIBODY- TABAR Farid, Laboratoire d’Energie et de Mécanique Théorique et Appliquée (LEMTA)
• Doctoral School    Chimie - Mécanique - Matériaux - Physique (C2MP) http://doctorat.univ-lorraine.fr/fr/les-ecoles-doctorales/c2mp/presentation
• IFPEN supervisor    PhD Engineer, HAJE OBEID Najla, Control and Diagnostic R&D Engineer, electrified system department najla.haje-obeid@ifpen.fr
• PhD location    IFP Energies nouvelles, Rueil-Malmaison, France
• Duration and start date    3 years, starting not earlier than September 2021
• Employer    IFP Energies nouvelles, Rueil-Malmaison, France
• Academic requirements    University Master degree or Engineering degree in electrical engineering
• Language requirements    Fluency in French or English
• Other requirements   Strong knowledge in electromagnetics, modelling of electrical machines and in signal processing