Three-level neutral-point-clamped (NPC) inverters are very appropriate for high-power adjustable-speed drive applications. Direct torque control is characterized by the merits of fast response, simple structure and strong robustness to motor parameters variations. This paper presents a 3-level inverter-fed direct torque controlled (DTC) induction motor (IM) drive based on optimized switching ta...

This paper proposes a new non‐magnetic motor with a rotor rotated by using the resonance en‐ ergy of a bimorph cantilever beam excited by electrostatic force. The use of flexible material en‐ ables conversion of translational vibration to rotary movement in one direction. Basic character‐ istics of a prototype motor with two bimorph cantilever beams, such as rotational speed, output torque, and...

This paper deals with a comprehensive study on reducing cogging torque generated in Brushless DC motor drives (BLDC). In such drives, cogging torque suppression techniques that are practically effective in low speed as well as high speed regions are scarcely found in literature. A well-known skewing technique is adapted in the stator slots to reduce the cogging torque using CAD package Magnet 6...

Random torque disturbances generated by magnetic bearings eccentric magnetic force have negative effects on the output torque precision of the magnetic suspended reaction flywheel(MSRFW). In order to eliminate the negative effects, dynamic models of flywheel system including motor and the buck DC-DC converter are established and a synergetic control approach for speed mode operation is presente...

Bone drilling is widely used in orthopaedics and surgery; it is a technically demanding surgical procedure. Recent technological improvements in this area are focused on efforts to reduce forces in bone drilling. This study focuses on forces and a torque required for conventional and ultrasonically-assisted tool penetration into fresh bovine cortical bone. Drilling tests were performed with two...

The paper deals with an adaptive speed controller design for a brushless DC motor drive. The controller structure include also a load-torque estimation approach in order to achieve a robust accurate path tracking. The design procedure is based on the fieldoriented control loop so as the controller itself will has two components: a two degree of freedom speed controller and a feed-forward load-t...

New downhole turbine generator can transmit the high speed rotation of the turbine to the rotor of the generator without contact by magnetic transmission mechanism to provide continuous power. Driving torque on magnetic transmission mechanism is a key parameter. This paper mainly studies the field on magnetic transmission mechanism of downhole turbine generator by using ANSYS software. The effe...

A variable-speed, constant-pitch wind turbine was investigated to evaluate the feasibility of constraining its rotor speed and power output without the benefit of active aerodynamic control devices. A strategy was postulated to control rotational speed by specifying the demanded generator torque. By controlling rotor speed in relation to wind speed, the aerodynamic power extracted by the blades...

This paper proposes a new electrically controlled magnetic variable-speed gearing (EC-MVSG) machine, which is capable of providing controllable gear ratios for hybrid electric vehicle (HEV) applications. The key design feature involves the adoption of a magnetic gearing structure and acceptance of the memory machine flux-mnemonic concept. Hence, the proposed machine can not only offer a gear-sh...

In this paper, a fault tolerant control for induction motors based on backstepping strategy is designed. The proposed approach permits to compensate both the rotor resistance variations and the load torque disturbance. Moreover, to avoid the use of speed and flux sensors, a second order sliding mode observer is used to estimate the flux and the speed. The used observer converges in a finite tim...