A mitigation technique for torque ripple in a brushless DC motor by controlled switching of small DC link capacitor

Abstract

High performance applications are now days utilizing the brushless DC motor (BLDC) drives due to its ruggedness, compactness, high torque to weight ratio, high dynamic response etc. the feature of square-wave current excitation waveforms in BLDC motor drives allows some major system simplifications for trapezoidal BLDC motors. The developed torque is constant in ideal conditions in this motor when its back emf waveform is of trapezoidal type. Despite this, due to the physical construction of the motor and its settings, torque ripple exists in the output torque and is an undesired phenomenon in the BLDC motor drives and are also linked to the motor's control and driver sides. This paper provides a new way for reducing torque ripple and is simple, compact and cost effective. To prove the correctness of the compensation technique, circuit is modelled and simulations are carried to examine the theoretical performance of the BLDC motor drive. Experiments on a prototype drive were conducted to further validate the theoretical analysis as well as the utility of the proposed technique.

A novel technique for torque ripple suppression in BLDC motor drive using switched capacitor based SEPIC converter

“…Thus, the proposed converter which offers lower THD helps maintain high voltage gain with lower voltage stress across the switch and in turn helps to minimize torque ripple. The proposed drive offers better solution to torque ripple suppression as compared to the complicated modulation technique presented in [8] and complex circuit analysis presented in [26].…”

Speed control of brushless DCmotors using (conventional, heuristic, and intelligent) methods-based PID controllers

“…The BLDC motor has a permanent magnet rotor and three stator windings. Rotor-induced currents need not be taken into account, and no damper windings need to be modeled because of the high electrical conductivity of the stainless steel retaining sleeves and the magnet [14]- [19]. The mathematical model for the three-phase BLDC motor.…”

Diagnosis of fault brush winding stator induction motor using external sensor flux of three axes

“…When current flows through the stator, it induces a rotating magnetic field, which in turn generates flux and sets the rotor into motion [18]. Achieving equilibrium in the current passing through the stator will produce a balanced flux [19]. Nevertheless, if there is a disruption in the stator winding, like a short circuit, it will result in an uneven current distribution, leading to an asymmetrical flux, which in turn gives rise to stray flux emanating around the motor [20].…”