Nowadays, light electric vehicles are usually powered by drives with motors that use rare-earth permanent magnets. Nevertheless, due to the problems these materials present, light electric vehicle manufacturers are open to considering other alternative drives free of permanent magnets. This paper raises a comprehensive comparison between a surface permanent magnet synchronous motor and a segmented stator switched reluctance motor with aluminum windings for light electric traction, specifically for a motorcycle similar to the Super Soco TCmax. Key words. Light electric vehicles, Power-train, Permanent magnet synchronous drives, Switched reluctance motor drives.

The electric motorcycle is a focus of increasing interest in the electric vehicle market. Usually, electric motorcycles are propelled by powertrains using permanent magnet synchronous motor drives. This paper proposes a segmented stator-switched reluctance motor drive as an alternative. The main goal is to present a control system that ensures the powertrain's operation across all speeds. Additionally, it aims to reduce the size of the DC-link capacitor with a smooth torque with lower ripple, particularly at low speeds. The system will combine direct torque control in the lowspeed range and current chopping control or angle pulse control with variable turn-on and turn-off angles in the medium to high-speed range. Simulation results demonstrate the goodness of the proposal.

Outside-spin brushless D.C. motors are an alternative to conventional D.C. brush permanent magnet motors, especially in applications that require low power and costs and in which high inertia effects are advantageous.This paper presents a procedure for computing power losses in these kinds of machines.Expressions are derived for predicting copper losses, power interrupter losses, stator iron losses in the tooth and in the yoke, mechanical losses, friction and windage.Stray load losses are also considered and evaluated from previous measurements in outside-spin brushless D.C. motors.The results obtained from the approach proposed are compared to those measured on existing motors, showing a good agreement.

The light electric vehicle market requires better performance motors with less or even without permanent magnets. Switched reluctance motors (SRM) are among the best placed to meet this goal, despite they have lower power density, higher torque ripple, and are noisier than synchronous permanent magnet motors. Segmented stator switched reluctance motors (SSSRM) can reduce these drawbacks of conventional SRMs due to their modular construction and shorter flux paths. This paper presents a procedure for designing an SSSRM for a light electric vehicle. First, the output torque equation is derived from a simplified nonlinear energy conversion loop, and then guidelines for its design are given. Once the preliminary sizing of the SSSRM has been carried out, simulation using electromagnetic finite element analysis is performed. Then, the complete drive is simulated and validated using Matlab-Simulink and some results of the definitive finite element analysis (magnetization curves and static torque curves).

This paper considers the application of flux switching alternators for small wind generation.First, after a brief presentation of the small wind energy systems, a description and the fundamentals of flux switching machines is given, then the state of art of flux switching generators is presented.Finally a critical assessment is shown, considering the main advantages and drawbacks of this type of machines as alternator for use in small wind generation systems. .

This paper is about hybrid reluctance machines, in which the stator or fixed part has a combination of U-shaped electromagnets with permanents magnets placed between their arms while the moving part is simply a structure with salient poles.They can be designed to build different types of rotary or linear electric motors and generators with outstanding performances.In this paper, first, the principle of operation of these machines is explained.Then different types of hybrid reluctance machines using this particular structural configuration are described showing their potential based on simulations and experimental results.

In this paper, a novel in-wheel double rotor axial flux switched reluctance motor for electric traction is presented. The proposed double rotor axial-flux switched reluctance motor has a particular disposition of the stator and rotor poles that provides short flux path without flux reversal. The ferromagnetic pieces of the stator and the rotor are built using soft magnetic composites. Electromagnetic analysis is performed using three dimensional finite element analyses, 3D FEA. Matlab-Simulink simulation coupled with the results of finite element analysis proves that the proposed motor drive is suitable for the propulsion of a given E-scooter.

This paper describes an electronic device that enables AC contactors to ride through power quality disturbances. The proposed device is connected to the contactor coil and consists of a power conversion excitation and hold-in circuit, a control circuit, an immunity circuit and a shutdown circuit. It does not disturb contactor operation, is easy to use and can be built from cheap, commercially available components. Experimental tests have demonstrated the effectiveness of the proposed electronic device for improving the immunity of AC contactors during power quality disturbances, particularly voltage dips.

A current-controlled switched reluctance motor drive for variable speed applications with efficiency optimization is presented.Firing angles are computed online, the turnon is calculated by means of the rule of Bose, and the turn-off is calculated using the general theory of the optimal turn-off angle proposed by Gribble.In steady state operation, the initial selection of firing angles is fine-tuned by means of an algorithm that minimizes the input power of the drive.An efficiency and electrical energy consumption comparison with a commercial vector-controlled induction motor drive of the same size is also included.Experimental results show that the proposed switched reluctance motor drive is a good choice for applications that require slow varying loads and energy savings.

Nowadays, there is a renewed interest in switched reluctance machines and especially in axial-flux switched reluctance machines (AFSRM). This paper presents a comprehensive design procedure for modular AFSRM with an inner stator and two exterior rotors that have a new distribution of the stator and rotor poles, resulting in short magnetic paths with no flux reversal. After a description of the proposed machine, the output torque equation is derived from a simplified non-linear energy conversion loop and guidelines for its design are given. Once the preliminary sizing has been carried out the different modules of the AFSRM, the magnetically active parts made with SMC, are reshaped or refined using 3D printing and 3D electromagnetic finite element analysis until they reach their definitive shape and dimensions. Finally, an AFSRM has been built following the proposed design procedure and has been validated by experimental measurements.

Switched Reluctance Machines (SRM) are emerging as a possible alternative in terms of cost and supply stability to rare earth based electric vehicle traction systems. However, because of the huge amounts of energy stored and transferred back and forth between the DC source and the SRM, large DC-link capacitors must be used as buffers, which increases overall costs and size. This paper proposes a novel modulation technique which forces the exchange of energy between phases while decreasing the energy transfer between the DC bus and the SRM. This means lower DC bus currents (capacitor size and cost reduction) and lower Joule-effect conduction losses (better efficiency). The proposed modulation has been validated experimentally in a test bench and compared with the conventional torque-sharing function.

In this paper, a novel two-phase linear hybrid reluctance actuator with the double-sided segmented stator, made of laminated U cores, and an interior mover with permanent magnets is proposed. The permanent magnets are disposed of in a way that increases the thrust force of a double-sided linear switched reluctance actuator of the same size. To achieve this objective, each phase of the actuator is powered by a single H-bridge inverter. To reduce the detent force, the upper and the lower stator were shifted. Finite element analysis was used to demonstrate that the proposed actuator has a high force density with low detent force. In addition, a comparative study between the proposed linear hybrid reluctance actuator, linear switched reluctance, and linear permanent magnet actuators of the same size was performed. Finally, experimental tests carried out in a prototype confirmed the goals of the proposed actuator.

In a near future when Industry 4.0 is implanted, predictive maintenance will have a much more prominent role than that currently plays in traditional industry. Predictive maintenance is the organized monitoring with periodic or continuous measurement of variables of the state of the equipment to be maintained and its comparison with pre-established patterns for the determination of the instant in which the maintenance intervention should take place. Three-phase induction motor drives are one of the industrial equipment that has been given greater attention regarding predictive maintenance plans. In recent years, switched reluctance motor drives have begun to have some relevance in the industry. In this paper, after a brief review of the switched reluctance motors and their control, an analysis of the different types of faults and a description of the most usual diagnostic techniques in electric drives, a predictive maintenance plan for switched reluctance motor drives is proposed. This predictive maintenance plan considers different control strategies (hysteresis and single pulse), and is based on diagnostic techniques such as analysis of currents and spectral analysis of vibrations. Exhaustive experimental tests have been carried out in order to validate the proposed plan.

This paper investigated the influence of manufacturing and assembly defects and the quality of materials on the performance of an axial-flux switched reluctance machine (AFSRM). An AFSRM drive was designed and built for the in-wheel propulsion of an electric scooter. The motor was tested according to the standard IEC 60349-Part 1, but the obtained results were below the expected result. The causes of the discrepancy between the simulated and experimental results were analyzed. After an exhaustive study, manufacturing and assembly deficiencies and the quality of materials were identified as the main causes of the mentioned discrepancies. Static torque was used to assess the impact of the different causes in these discrepancies. Finally, some recommendations are proposed to improve the construction of this kind of machine.

For many designers of electrical machines, the term “soft magnetic materials” automatically means laminated electrical sheet. This is unfortunate, since for many applications, particularly at low frequencies, laminated sheet is rarely the best material choice. Soft magnetic powder materials are available to satisfy the needs of virtually any application imaginable, from plain iron, giving good induction for DC applications, to ultrahigh permeability nickel irons. The use of these materials brings with it all the attendant advantages of powder metallurgical (PM) production: low cost, tight tolerances, complicated forms, and minimal material waste. For high frequency applications, a range of soft magnetic composite materials or SMCs are available which can provide magnetic performance comparable to or surpassing that of laminated sheets, while at the same time allowing much greater freedom to the designer due to their isotropic nature, which permits the implementation of complicated 3D flux paths. This paper presents a review of the available powder-based soft magnetic materials, together with typical applications and a consideration of some of the factors which must be taken into account when producing powder-based components for magnetic applications. Keywords—soft magnetic materials, powder metallurgy, sinter, SMC, dielectromagnetic

Nowadays, switched reluctance motor drives are one of the most promising alternatives for the elimination of permanent magnets in the electric traction systems, due to their well-known advantages such as simple and rugged construction, high efficiency, speed torque characteristic well adapted to traction needs and despite their drawbacks high torque ripple and high acoustic noise. Unfortunately, nowadays, the lack of commercial controllers intended for switched reluctance motors slows down its use as power traction unit. This paper tries to overcome this barrier proposing a specific controller, understood as the assembly of electronic power converter and control unit, for electric light vehicles. First, the specifications of the controller will be exposed then a comprehensive description of the architecture of the controller and details about the choice of its components will be given. Finally, experimental results will be shown in order to demonstrate its suitability as a SRM controller for light electric vehicles.

The objective of this paper is to present an original study for optimizing the size of the longitudinal-flux double-sided linear switched reluctance motor (LSRM) under thermal and weight constraints. The performance is evaluated taken into account duty cycle operating conditions and thermal restrictions. The proposed approach couples finite element analysis for magnetic propulsion force computation and lumped-parameter thermal network for thermal transient analysis. The LSRMs design parameters are characterized by the number of phases and by their size denoted by the pole stroke. The operating conditions are the current density, the duty cycle and the admissible temperature rise of the insulation system. The grid search algorithm is used for solving the optimization problem. From the results, with the help of a novel multivariable optimization chart, a set of optimal configurations regarding to miniaturizations and downsizing of LSRMs is provided.

Electrification of road vehicles is one of the most consistent initiatives to achieve a clean, environmentally friendly and efficient transport system. The choice of the electric machine for the powertrain is an important consideration, nowadays tilted towards permanent magnet synchronous machines. However, rare earth permanent magnet supply drawbacks open up new prospects for other types of machines, such as switched reluctance machines (SRM). This Workshop, Switched reluctance motor drives an alternative for E-traction, aims to deepen into the potential of SRM for electric traction, to be a meeting point for groups that are currently working on the development of SRM drives and an opportunity to establish future collaborations. The Workshop consists of two parts. In the first part, participants will present papers about issues related with switched reluctance machines for electric traction applications. In the second part, they will discuss what aspects slow down the application of SRM drives for electric traction and their possible solutions.

In this paper a novel axial-flux segmented rotor switched reluctance motor (AFSSRM) with a stator sandwiched by two rotors with a particular form of the segments is presented. The machine has magnetic short paths with no flux reversal and the active magnetic parts are made of soft magnetic composites. An in-wheel AFSSRM, specially intended for direct drive of light motorcycles, is designed. Electromagnetic analysis of the AFSSRM is carried out using 3D finite element. Matlab-Simulink simulations of the whole in-wheel AFSSRM drive are used to verify its behavior.

The teaching of electrical machines and drives requires a new approach to make them more attractive to students, to address and overcome the limitations of time and resources that are usual in electrical engineering programs. The target of this new approach is that after following the course students should have a consistent knowledge and skills on electric machines and drives that gives them the ability to deal, with solvency, any problem related with them. In this paper, following these assumptions, reluctance motors are introduced considering that the different types of reluctances motors are derived from a common origin that is the singly-excited electromechanical converter. Then the fundamentals of switched reluctance motors, steeping variable-reluctance motors and synchronous reluctance motors are presented. The proposed approach requires only some basic knowledge that is usually taught in the courses of electric machines and drives and allows students to learn and understand the basis of the reluctance motors very quickly.