Showing 5 results for Torque Ripple
A. Halvaei-Niasar, A. Vahedi, H. Moghbelli,
Volume 3, Issue 3 (7-2007)
Abstract
This paper presents an original study on the generated torque ripples of phase
commutation in the Four-Switch, Three-Phase Inverter (FSTPI) Brushless DC (BLDC)
motor drive which is suitable for low cost applications. Analytic values of torque ripple and
commutation duration are obtained for different operation conditions. Moreover, limitation
on the speed range operation caused from splitting of the DC-link voltage is shown exactly.
Then a novel current control technique is developed to minimize the commutation torque
ripple for a wide speed range. The technique proposed here is based on a strategy that the
current slopes of the rising and the decaying phases during the commutation intervals can
be equalized by proper duty-ratios at commutations. Finally, the validity of the proposed
analysis and developed torque ripple reduction technique are verified via simulation.
M. R. Feyzi, Y. Ebrahimi,
Volume 5, Issue 3 (9-2009)
Abstract
A switched Reluctance motor (SRM) has several desirable features, including
simple construction, high reliability and low cost. However, it suffers from large torque
ripple, highly non-uniform torque output and magnetization characteristics and large noise.
Several studies have succeeded in torque ripple reduction for SRM using Direct Torque
Control (DTC) technique. DTC method has many advantages over conventional voltage
control and current chopping mode control such as simple algorithm, less torque ripple and
instantaneous response to the torque command. In this paper, DTC method is proposed for
a 5-phase 10/8 SRM. The performance of the motor is demonstrated through the computer
simulation in Mtalab/Simulink. Then, the obtained results are verified by comparison with
the corresponding results of a 3-phase 6/4 motor performance.
S. R. Mousavi-Aghdam, M. R. Feyzi, Y. Ebrahimi,
Volume 8, Issue 1 (3-2012)
Abstract
This paper presents a new design to reduce torque ripple in Switched Reluctance Motors (SRM). 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 value. An optimization using fuzzy strategy is successfully performed after sensitivity analysis. The two dimensional (2-D) finite element method (FEM) results, have demonstrated validity of the proposed new design.
M. M. Namazi Isfahani, A. Rashidi, S. M. Saghaiannejad,
Volume 8, Issue 1 (3-2012)
Abstract
Torque ripple minimization of switched reluctance motor drives is a major subject based on these drives’ extensive use in the industry. In this paper, by using a well-known cascaded torque control structure and taking the machine physical structure characteristics into account, the proposed energy-based (passivity-based) adaptive sliding algorithm derived from the view point of energy dissipation, control stability and algorithm robustness. First, a nonlinear dynamic model is developed and decomposed into separate slow and fast passive subsystems which are interconnected by negative feedbacks. Then, an outer loop speed control is employed by adaptive sliding controller to determine the appropriate torque command. Finally, to reduce torque ripple in switched reluctance motor a high-performance passivity-based current controller is proposed. It can overcome the inherent nonlinear characteristics of the system and make the whole system robust to uncertainties and bounded disturbances. The performance of the proposed controller algorithm has been demonstrated in simulation, and experimental using a 4KW, four-phase, 8/6 pole SRM DSP-based drive system.
H. Davari, Y. Alinejad-Beromi,
Volume 16, Issue 1 (3-2020)
Abstract
In this paper, at first, a 24/16 three-phase switched reluctance motor is designed, then the rotor poles shape tips corrected for reduction ripple of single-phase torque waveform. By doing this, the single-phase torque waveform has a flat surface and consequently, the single-phase torque ripple is reduced. Also, due to the commutation between the machine phases, the torque drops during this time, which are known as torque pits. To reduce the ripple torque at these points, which requires overlap between the two successive phases of the machine, the pulse width of the excitation of the machine phases is adjusted. Comparisons have been made between two types of direct current excitation and chopped current (with different pulse widths). The results show that for constant pulse width under chopped current, applying the arc and modifying the shape of the rotor poles can reduce the torque ripple by 3.4%. Also, by applying chopped current control, the torque ripple was reduced by 46.7% compared to its conventional design structure.
