Switched Reluctance Motors (SRM) have inherent advantages such as simple structure with non winding construction in rotor side, fail safe because of its characteristic which has a high tolerances, robustness, low cost with no permanent magnet in the structure, and possible operation in high temperatures or in intense temperature variations. The torque production in switched reluctance motor com...

In classical control of brushless dc motors, flux distribution is assumed trapezoidal and fed current is controlled rectangular to obtain a desired constant torque. However, in reality this assumption may not be correct due to nonuniformity of magnetic materials and design trade-offs. These factors together with current controller limitation, can lead to an undesirable torqueripple. Hence torqu...

This paper presents the modelling of asymmetries of phase parameters (inductances) of permanent magnet (PM) synchronous motor and the analysis of the impact of these asymmetries on the instantaneous torque. The torque ripple created by phase asymmetries is simulated for three operating conditions – current-fed, voltage-fed and vector control operation, using specifically developed mathematical ...

After much research and developments in the fields of magnetic materials their application to electric motor drives has increased to a significant extent. AC motors with permanent magnet rotors are available as brushless DC motors (BLDCM) for both domestic and industrial applications. With the advancements in power electronics, the control of Brushless DC machine has become more flexible for va...

Received Feb 14, 2017 Revised Apr 14, 2017 Accepted Apr 29, 2017 Brushless DC (BLDC) motors are becoming an increasingly popular motor of choice for its unique characteristics. The BLDC motor drive is assumed to have trapezoidal back-electromotive force (EMF), rectangular phase currents and together produces the desired torque. However, practical back-EMF waveform might not be exactly trapezoid...

The Direct Torque Control (DTC) of induction machine has received wide acceptance in many Variable Speed Drive (VSD) applications due to its simple control structure and excellent torque dynamic control performances. However, the conventional DTC which employs a two-level inverter and hysteresis controllers produces two major drawbacks, namely, larger torque ripple and variable switching freque...

The matrix converter system is competitive solution to replace the conventional two stage ac to ac converter. In this paper, a matrix converter driving a speed-controlled induction machine is examined under open-switch fault. First, a-predictive direct torque method is proposed using only the motor torque and current. Second, a motor speed control is presented. The proposed techniques do not re...

DTC is strategy of selecting proper stator voltage vectors to reduce torque error and flux error. DTC uses hysteresis band controller whose control action has no difference between large torque error and small one. This results in high torque ripple. In order to reduce the torque ripple and to improve the performance of DTC, DTC based on Fuzzy Logic is proposed in this paper. The simulations ar...

Abstract – In direct torque control, the selection of an applied voltage vector is based on the measured parameters at the beginning of the sampling period. The delay between the measurement and the application of the voltage vector is the origin of an extra torque ripple. In this paper, a new predictive controller is proposed for compensating this delay and reducing the torque ripple. The stat...

The basic concept of direct torque control of induction machines is investigated in order to emphasize the effects produced by a given voltage vector on stator flux and torque variations. The low number of voltage vectors which can be applied to the machine using the basic DTC scheme may cause undesired torque and current ripple. An improvement DTC schemes proposed in the research literature is...