J.I. Perat

Improving efficiency in switched reluctance motor drives with online control of turn-on and turn-off angles

A current controlled switched reluctance motor drive for variable speed applications with efficiency optimisation is presented. Firing angles are computed online, the turn-on 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. A 6/4 switched reluctance motor drive prototype was tested and the experimental results show an improvement in online efficiency, a good steady-state performance and no deterioration in the dynamic response. An efficiency comparison with a commercial vector-controlled induction motor drive of the same size is also included

Environmental and life cycle cost analysis of a switched reluctance motor

This paper presents an analysis of the environmental and life cycle costs of a switched reluctance motor (SRM) drive. The analysis was carried out according to the Energy-Using Product Directive (EuP 2005/32/EC) and following the Methodology for the Eco-Design of Energy-Using Products (MEEUP methodology). The base case model adopted is an 8/6 SRM with 1.5 kW of output power that can be considered representative of the small power range. The analysis shows that SRMs could generate large savings comparable to or even better than those of Eff1 three-phase induction motors in the use phase.

A new power supply system for AC contactor ride-through

This paper describes a new power supply system that enables an AC contactor to ride through power grid disturbances. The proposed system is implemented in an electronic device that is connected to the contactor coil. The electronic device consists of a power conversion and excitation circuit, a control circuit, an immunity circuit and a shutdown circuit. It does not disturb the contactor operation and can be adapted to almost all types of electrical contactor. Experimental tests have demonstrated the effectiveness of the proposed electronic device.

Post-fault performance of a fault-tolerant switched reluctance motor drive

Switched reluctance motor (SRM) drives are well suited for use as fault tolerant drives. After identifying and isolating a fault that may occur, these drives can continue to operate and maintain the rated output without the faulted phase, although they do exhibit some performance disturbances. This paper presents an SRM drive with fault tolerant capabilities and analyses its post-fault performance. This analysis, based on experimental study using a prototype SRM drive, emphasizes certain magnitudes that exhibit external effects such as vibration, noise and temperature

New linear hybrid reluctance actuator

In this paper a new type of hybrid reluctance actuator is presented. This linear hybrid reluctance actuator is a two phase double sided actuator in which the stator is composed by four normalized U cores, each with a coil wrapped around the yoke connecting the two arms of the core or with two coils wound on each of the arms and a permanent magnet placed near the air gap between and in contact with both arms. The mover is comprised of rectangular poles without connecting iron pieces between them but mechanically joined by non-magnetic mounting parts. The magnets are arranged so that their flux is in parallel to the flux created when the coils are energized, both fluxes are added and the total reinforced flux links the stator and the mover. But when no currents flow through the coils no flux crosses the air gap, and the flux of the magnets is closed through the back iron that supports them. An analysis and simulation of the motor using 2 D finite element and MATLAB Simulink is carried out. Finally, a comparison of this type of actuator with respect a linear reluctance stepper motor of the same size is shown.

Experimental determination of magnetic characteristics of electrical machines

A test equipment for determination of magnetic characteristics of different kinds of electrical machines is presented. Experimental determination of magnetic characteristics of electrical machines should be understood, according to the machine studied, as determination of their corresponding inductances or as determination of their magnetization curves (flux-linkage versus current for different rotor positions). The test equipment is based on a method of measurement of inductance by means of DC current, proposed by C.V. Jones, in which a bridge arrangement is used in order to eliminate the resistance effects. This equipment is able to obtain armature inductance in DCM (direct current motor), d-axis and q-axis inductance in SPSM (salient-pole synchronous machine) or SYNCREL (synchronous reluctance motor) and magnetization curves of SRM with a good accuracy and in an automatic way. The main advantage of this setup is that it is an automatic system controlled by PC, that allows magnetic characteristics of almost any electrical machine to be obtained, reducing measurement time and manual errors and providing easy and user friendly presentation of the test results. Several examples of experimental determination of magnetic characteristics using the proposed equipment are shown proving their test capabilities.

New axial-flux switched reluctance motor for e-scooter

The world market of e-scooter is expected to experiment an increase of 15% in Western Europe between 2015 and 2025. In order to push this growth it is needed to develop new low-cost more efficient and reliable drives with high torque to weight ratio. In this paper a new axial-flux switched reluctance motor is proposed in order to accomplish this goal. The motor is constituted by a stator sandwiched by two rotors in which the ferromagnetic parts are made of soft magnetic composites. It has a new disposition of the stator and the rotor poles and shorter flux paths Simulations have demonstrated that the proposed axial-flux switched reluctance motor drive is able to meet the requirements of an e-scooter.