M. Asgar, E. Afjei,
Volume 5, Issue 4 (December 2009)
Abstract
Switched reluctance motor (SRM) drive has a remarkable characteristic, high efficiency, and good controllability, which makes it attractive for high-speed applications. In this paper, the basic control strategy for a switched reluctance motor drive circuit is explained and then three different resonant discharge topologies for SRM drive circuit are proposed. Due to resonantly discharging of excess energy, these topologies provide faster rate of fall for the phase current, which permits the motor to operate at higher speeds. In the new circuits a capacitor is charged resonantly by the use of motor phase windings during the phase turn off periods and then discharged via an inductor and a diode during the next working strokes. Three different drive circuits utilizing this process are proposed. A detailed explanation and demonstration of the converter circuits have been presented.
E. Afjei,
Volume 8, Issue 2 (June 2012)
Abstract
The switched reluctance motor is a singly excited, doubly salient machine which
can be used in generation mode by selecting the proper firing angles of the phases. Due to
its robustness, it has the potential and the ability to become one the generators to be used in
harsh environment. This paper presents an energy conversion by a Switched Reluctance
Generator (SRG) when bifilar converter circuit and discrete position sensors are employed.
As the generator’s speed increases by a prime mover the shape of current waveform
changes in such a way that limits the production of generating voltage. At high speeds, it is
possible for the phase current never reaches the desired value to produce enough back-emf
for sufficient voltage generation, therefore, the output power falls off. In order to remedy
this problem, the phase turn on angle is advanced in a way that the phase commutation
begins sooner. Since one of the advantages of this type of generator is its variable speed
then, the amount of advancing for the turn on angle should be accomplished automatically
to obtain the desired output voltage according to the speed of the generator, meaning, as the
generator speed increases so should the turn on angle and vice versa. In this respect, this
paper introduces an electronic circuit in conjunction with the position sensors and the drive
converter to achieve this task for a desired output voltage when a SRG feeding a resistive
load. To evaluate the generator performance, two types of analysis, namely numerical
technique and experimental studies have been utilized on a 6 by 4, 30 V, SRG. In the
numerical analysis, due to highly non-linear nature of the motor, a three dimensional finite
element analysis is employed, whereas in the experimental study, a proto-type generator
and its circuitries have been built and tested using bifilar converter. A linear analysis of the
current waveform for the generator under different advancements of the turn on angle has
been performed numerically and experimentally and the results are presented.
P. Vahedi, B. Ganji, E. Afjei,
Volume 16, Issue 4 (December 2020)
Abstract
Using ANSYS finite element (FE) package, a multi-physics simulation model based on finite element method (FEM) is introduced for the multi-layer switched reluctance motor (SRM) in the present paper. The simulation model is created totally in ANSYS parametric design language (APDL) as a parametric model usable for various conventional types of this motor and it is included electromagnetic, thermal, and structural analyses. The static characteristic of flux-linkage with a phase, phase current waveform, instantaneous torque, and electromagnetic losses are predicted using the developed electromagnetic model. Carrying out 3D FE thermal analysis, the temperature rise due to the calculated core and copper losses is predicted in the developed thermal model. The transient, modal and harmonic analyses are done in the introduced structural model to determine the mode shapes, natural frequencies, displacement, and sound pressure level (SPL) in both time and frequency domains. In order to evaluate the developed simulation model, it is applied to a typical multi-layer SRM, and simulation results related to all the above-mentioned analyses are presented.
