This paper presents a new design to reduce torque ripple in Switched Reluctance Motors (SRMs). Although SRM possesses many advantages in terms of motor structure, it suffers from large torque ripple that causes problems such as vibration and acoustic noise. The paper describes new rotor and stator pole shapes with a non-uniform air gap profile to reduce torque ripple while retaining its average...

Higher productivity requires high-speed motion of machine tool axes. The iron core linear DC motor (LDM) is widely accepted as a viable candidate for high-speed machine tool feed unit. LDM, however, has two inherent disturbance force components, namely cogging and thrust force ripple. These disturbance forces directly affect the tracking accuracy of the feeding system and must be eliminated or ...

Since the magnetizing characteristics are highly non-linear in nature, the torque ripple is high in the Switched Reluctance Motor (SRM). The torque ripple can be minimized by using a novel control technique called Direct Torque Control (DTC). In DTC technique, torque is controlled directly through control of magnitude of the flux-linkage and change in speed of the stator flux vector. The flux a...

Although it is too early to evaluate the long-run socio-economic effects of economic liberalisation and privatisation, along with the overall globalisation process, on a dualistic economy like India's, the paper will first examine the often-raised concern that these economic changes have, in general, led to the erosion of living standards of the poor; increase in regional disparities in terms o...

This paper addresses torque-ripple reduction in current-fed switched reluctance motors (SRMs). Ripple-free torque production in SRMs requires an accurate model that is often too complex for practical implementation. The algorithm proposed here combines the use of a simplified model with adaptation. Explicitly, it includes dynamic estimation of low harmonics of the combined unknown load torque a...

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 generated torque ripple in switched reluctance motors (SRM) can be considered as one of the major disadvantages of the motor. It is mainly due to frequent switching of phases for rotation of the motor and changes of the air gap length between the rotor and stator teeth. It decreases the average developed torque, diminish the efficiency, causes noise and vibration in the motor. So, in order ...

Abstract: A method is proposed for reducing speed ripple of permanent magnet synchronous motors (PMSMs) controlled by space vector pulse width modulation (SVPWM). A flux graph and mathematics are used to analyze the speed ripple characteristics of the PMSM. Analysis indicates that the 6P (P refers to pole pairs of the PMSM) time harmonic of rotor mechanical speed is the main harmonic component ...

The number of internet web applications is rapidly increasing in a variety of fields and not much work has been done for ensuring their quality, especially after modification. Modifying any part of a web application may affect other parts. If the stability of a web application is poor, then the impact of modification will be costly in terms of maintenance and testing. Ripple effect is a measure...