Rolling bearing faults are generally slowly progressive; therefore, the development of an effective diagnostic technique could be worth detecting such faults in their incipient phase and preventing complete failure of the motor. The methods proposed in the literature for this purpose are mainly based on measuring and analyzing vibration and current. Here, a novel technique based on the stray flux measurement in different positions around the electrical machine is proposed. The main advantages of this method are due to the simplicity and the flexibility of the custom flux probe with its amplification and filtering stage. The flux probe can be easily positioned on the machines and adapted to a wide range of power levels. This paper also reports an extensive survey on the stray-flux-based fault detection methods for induction motors, prior to introducing a novel sensor/diagnostic scheme.

In safety-critical systems, faults can cause life losses, environmental degradation, or significant financial losses. In this paper, a segmental stator switched reluctance machine is proposed for such applications. A short overview of its design is given. Its fault tolerance is investigated by dynamic simulations and laboratory tests. It is demonstrated via both methods that the proposed machine is able to have a continuous operation despite five severe winding fault conditions.

A modular stator switched reluctance motor (SRM) for fault tolerant drive systems is proposed. Owing to the particular construction of the stator there is no mutual coupling between adjacent phases. Hence, the motor can work also when a part of the coils is faulted and the faulted modules can be replaced without uncoupling the machine from the load or gearbox. The sizing particularities are presented and the mathematical model of the motor is developed. The results obtained via finite element analysis are compared with the analytical ones, and with that resulting after testing the constructed laboratory model. All these prove that the proposed SRM can be used in safety–critical drives.

There is a strong general demand for the permanent improvement of electrical machines. Nowadays, these are at their near maximum potential, and even small further improvements can only be achieved with great effort and high cost. The single solution should be a paradigm shift in their development, by using radically new approaches to topology, materials, and fabrication. Therefore, the application of diverse 3D printing techniques for advanced fabrication in this field is inevitable. Therefore, these new approaches are receiving a great deal of attention among electrical machines designers. In the paper, the possible applications of these new fabrication technologies in the field of electrical machines are surveyed. The focus is set on emphasizing the advancement over the traditional manufacturing approaches.

The energy received on Earth from the Sun is plentiful and totally renewable. Basically, the sun enabled life on our planet, and our life cannot be imagined without it. The sun is directly or indirectly at the origin for nearly all the energy resources on Earth, as fossil fuels (coal, natural gas and oil), hydro (global water circulation is due to the sun), wind, waves, biomass, etc. The sunlight was used as an energy resource already by ancient civilizations. Since than a lot of innovative technologies and advancements were performed in this field. The paper presents the main milestones of the developments performed in this important field of energy conversion.

This paper deals with the proposition of a permanent-magnet (PM) machine used to motorize an electric scooter. Several electrical machine configurations are discussed, and the best solution is chosen. The power density and the energetic performances of the chosen machine (with a fractional-slot configuration) are improved using a hybrid optimization algorithm, which combines simulated annealing (SA) and particle swarm optimization (PSO) techniques. The obtained results are numerically and experimentally validated to prove that the proposed solution suites the scooter application.