Automatic detection of early-stage electrical faults in motors is challenging because physical signals, such as temperature or vibrations, are often linked to regular machine operation. Inter-turn short-circuit (ITSC) faults in the stator winding are a leading cause of irreversible damage. Given industrial demands, there is an ongoing need for innovative approaches that reduce dimensionality and expedite feature extraction from three-phase current signals. This work presents an ITSC multi-fault classification algorithm by modeling the behavior of three-phase stator currents in a complex space. To achieve this, two geometric-based and two optimization-based approaches are employed to parameterize the shape of the complex signal. Rather than directly extracting features from the raw signals, these parameters capture the similarities among incipient failures. The algorithm is evaluated using machine learning classifiers trained on a dataset generated from an experimental test bench and a publicly available dataset. The proposed method achieved an accuracy of 95.30% across 13 categories, demonstrating its robustness and reliability and positioning it as a highly competitive alternative to state-of-the-art techniques.
In the transportation industry, the use of renewable energies has been implemented in conjunction with the development of higher-power electric motors and, consequently, the development of intelligent control systems for torque and speed control. Currently, the coupling between both systems is being developed through mechanical systems, affecting the efficient transmission of energy and the useful life of the components. On the other hand, new configurations of electric motors are being developed, such as axial flux motors (AFM), because these can be coupled directly without a mechanical coupling, given their characteristics of high torque at low speeds. In the present work, an innovative design of a multipole axial flux motor (MAFM) is introduced. General criteria for the design and construction are presented considering the geometry in axial flux and permanent magnets. The performance of the system is evaluated through finite element magnetic simulations (FEMM) and compared with experimental measurements of the developed prototype; confirming the effectiveness of the design, obtaining torques of up to 1.784 Nm without extra mechanical couplings and maximum speed regulation errors of 8.43%. The motor was controlled by a digital pole switching system whit six control mode, applied to a permanent magnet MFA for speed and torque control at constant speed. This control can be extended to conventional radial flux electric motor configurations and intelligent traction applications, based on torque demand.
The use of renewable energies in the transportation industry has prompted the development of higher power electric motors and intelligent electronic traction systems. However, the typical coupling between the two continues to be mechanical, which reduces its efficiency and useful life. On the other hand, permanent magnet axial flux motor configurations make it possible to dispense with mechanical couplings, due to their high torque at low speeds due to their direct application on the wheels of vehicles. In this work, the design of a digital pole commutation system is presented, applied to an axial flux motor with permanent magnets for speed and torque control at a constant speed. The performance of the system is evaluated with experimental measurements; proving the effectiveness of the design, obtaining torques of up to 1784 Nm without extra mechanical couplings and maximum speed regulation errors of 8.43%.
17 July 2018 in IEEE Transactions on Applied Superconductivity
Linear Electric Generators (LEGs) are attractive devices for new efficient and sustainable ways of developing power generating technologies. This research work contributes in determining the increase of energy potential of LEGs while using superconductor coils instead of stator and actuator made of heavy and high permeability materials, necessary when conventional conductive material such copper is used to generate electrical energy. The proposed work highlights the techno-economic aspects of using superconductive materials in the LEG coil. Moreover, the design features of the LEG using superconductors, the electromagnetic analysis performance with finite element simulations and the experimentation results are presented. The comparison of the power extracted using copper coil and superconducting material is established, three times more power is obtained with superconductor coil.
3 July 2015 in International Journal of Thermophysics