This paper presents an improved Direct Torque Control (DTC) based on fuzzy logic technique. The major problem that is usually associated with DTC drive is the high torque ripple. To overcome this problem a torque hysteresis band with variable amplitude is proposed based on fuzzy logic. The fuzzy proposed controller is shown to be able to reducing the torque and flux ripples and to improve perfo...

This paper places of interest Direct Torque control (DTC) strategy for induction motor based on fuzzy logic control. Many methods of controlling the performance of induction motors exist. The direct torque control deserves special attention because of high performance vector control based on decoupling the stator flux and electromagnetic torque. In conventional method normal DTC is used to cont...

Simple power electronic drive circuit and fault tolerance of converter are specific advantages of SRM drives, but excessive torque ripple has limited their use to special applications. It is well known that controlling the current shape adequately can minimize the torque ripple. This paper presents a new method for shaping the motor currents to minimize the torque ripple, using a neuro-fuzzy co...

Permanent Magnet Machines (PMM) with a phase number (m) higher than three allow redundancy and lower torque ripple compared to their three phase counterparts. In this paper, a six phase permanent magnet machine with surface rotor magnets, designed with fractional slot tooth winding is proposed. A stator design with fractional slot tooth winding allows the design of a compact machine through sho...

This paper presents a method to reduce the commutation torque ripple in a position sensorless brushless DC motor drive. To compensate the commutation torque ripple considerably, the duration of commutation must be known. The proposed method measures the duration of commutation from the terminal voltage of the motor, calculates a PWM duty ratio using the measured commutation interval to suppress...

This paper presents the method of reducing torque ripple of brushless DC (BLDC) motor. The commutation torque ripple is reduced by control of the DC link voltage during the commutation time. The magnitude of voltage and commutation time is estimated by a neural network and optimized with an optimization method named particle swarm optimization (PSO) algorithm analysis. The goal of optimization ...

In a conventional three phase Brushless DC machine with 120° electrical conduction, Harmonics and commutation torque ripple occurs because of changeover of load current from one phase to another at every 60 electrical degrees. This paper presents techniques for diminishing the harmonics and torque ripples in sensor Brushless DC motor. This torque ripple reduction techniques based on voltage con...

The multi-degrees of freedom surface permanent-magnet motor (Multi-D.O.F. SPM) has several degrees of freedom operations that are defined as the “roll”, “yaw”, and “pitch”. Normally, the torque that is generated to rotate a rotor includes ripples. The analysis of the torque ripples is important for improving motor performance. In terms of the electric analysis, torque ripple occurs as a result ...

Due to the small inductance, modulation of three phase inverter induces serious torque ripple. In addition, the increase in modulation frequency is limited by the processor speed. Therefore, the traditional torque control approaches are not suitable. In order to solve the aforementioned problems, a new instantaneous torque control method for small inductance brushless dc motor is proposed by im...

Based on the analysis of the principle of torque ripple with commutation time for brushless DC motor, this paper proposes a method to restrain commutation torque ripple. This method is an improved predictive current control. First, an expression is built about the torque ripple during commutation time. After analysis, the non-commutation phase current is related to torque ripple. Then, a kind o...