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...

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...

The conventional direct torque control (CDTC) is known to produce quick and robust response in induction motor drives. However, during steady state, torque, flux and current occur, which results in acoustical noise and incorrect speed estimations. The main objective of this paper is to present different hybrid space vector PWM (HSVPWM) methods for direct torque controlled induction motor for re...

This paper proposes a regulation method of back-toback connected three-level converters in order to reduce the torque ripple in induction motor. First part is dedicated to the presentation of the feedback control of three-level PWM rectifier. In the second part, three-level NPC voltage source inverter balancing DC bus algorithm is presented. A theoretical analysis with a complete simulation of ...

Two different external-rotor-internal-stator TORUS type axial flux PM machines can be derived based on the direction of the flux. In the first type of the TORUS machine, magnet driven flux enters stator and travels circumferentially along the stator core while in the second type the flux enters the stator and travels axially along the machine axis of rotation. The major differences between the ...

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...

In the current paper, the optimization shape of a polysilicon variable-capacitance micromotor (VCM) was determined using the seeker optimization algorithm (SOA). The optimum goal of the algorithm was to find the maximum torque value and minimum ripple torque by varying the geometrical parameters. The optimization process was performed using a combination of SOA and the finite-element method (FE...

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...