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This paper deals with the investigation of a linear generator used in an internal combustion engine. The introduction reviews the state of the art of free-piston linear generators. Then, the mechanical structure of this generator is presented. The main part treats a finite-element-analysis (FEA) of the generator comparing different armature magnetizations with the numeric simulation program FLUX....
Due to its novelty in structure, the appealing force between rotor and stator disks, axial flux (AF) permanent magnet (PM) machine are easily affected by air-gap asymmetries. In the inner-rotor double-stator AF machine, the rotor disk is assembled between two outer stators. It is usually assumed that the air-gap clearance is ideal condition in electromagnetic analysis. However, manufacturing imperfections...
A fault-tolerant machine used for safety-critical tasks must a) guarantee at least a reduced-performance operation in case of partial machine fault and b) guarantee avoidance of drive mechanical jam/stall in case of total machine fault, to allow for the intervention of the back-up systems. Classical hydrostatic transmissions used on board ships for critical tasks such as rudder and stabilizing fin...
The switched reluctance motor is a good candidate for electrical traction and more specifically in automotive applications. The conventional switched reluctance motor presents two major drawbacks which are torque ripple and stator vibrations. In this work, a solution to limit these problems is proposed: a switched reluctance motor with magnetic slot wedges is used to reduce the impact of vibrations...
In this paper a new type of hybrid reluctance actuator is presented. This linear hybrid reluctance actuator is a two phase double sided actuator in which the stator is composed by four normalized U cores, each with a coil wrapped around the yoke connecting the two arms of the core or with two coils wound on each of the arms and a permanent magnet placed near the air gap between and in contact with...
The bearingless flux switching slice drive is a recently introduced motor topology in the field of bearingless drives. It combines the magnetic rotor suspension of bearingless slice drives with the torque generation of flux-switching motors. Due to lack of magnets embedded in the rotor, the topology offers advantages in applications with high temperature working conditions. This paper describes the...
Unbalanced magnetic pull in cylindrical electrical machines has been studied by several authors but it can be hard to quantify and measure. This paper reviews some of the work related to UMP calculation and measurement and develops the concept of a UMP index in order to allow comparative studies. This is because the UMP can vary greatly in terms of magnitude depending on the type and topology of the...
A novel combined sliding mode adaptive observer for flux and speed estimation of direct thrust controlled surface mounted Linear Permanent Magnet Synchronous Motor (LPMSM) without using position sensors is proposed. The observer comprises a linear state observer combined with a novel nonlinear sliding mode component. The sliding mode component is improved by using two boundary layers which reduce...
This paper deeply discusses the effect of eccentricity, including static, dynamic and mixed eccentricity on the performance of FSCW SPM servo motor analytically and using finite element analysis (FEA) to validation. The effect of different kinds of eccentricity on magnetic field including magnet field and armature reaction field is described with three factor called modulation factor. The frequency...
This paper describes the general design considerations and analysis for an industrial size electro-static (ES) motor/generator. The operation fundamentals, combined with FE (Finite Element) analysis are discussed with the target operation in the outer space or vacuumed environment. The torque production and limitations with high voltage electric field are analyzed and compared with conventional frame...
Long stator linear synchronous motor is the main drive unit of a magnetic levitation train. While a train runs, the electromagnetic fields produced by the armature current will result in the changes of the magnetic fields produced by the excitation current, and it will lead to a fluctuation of the levitation force, thus the train-running safety and stability of the train will be weakened. So, obtaining...
For one-dimensional platform driven by butterfly-shaped linear ultrasonic motor, the Takagi-Sugeno (T-S) models are approached through sector nonlinearity. Based on the T-S models the system augmented method is used for design of servo positioning control algorithm without steady-state error. By considering the robust H∞, a disturbance rejection controller design for the T-S fuzzy models is presented...
This paper deals with the design optimization of iron-cored linear motor with trapezoidal permanent magnets (PMs) configurations. Such motor is a short-stroke, single-phase tubular linear permanent magnet motor (TLPMM). The motor equipped with a quasi-Halbach magnetized moving-magnet armature and stator with a single slot and a single coil. The predicted magnetic field distribution in the airgap,...
This paper proposes a unified active locomotion mechanism for a capsule-shaped laparoscopic surgical camera system. The proposed design integrates the camera's fixation and manipulation together by adjusting a 3D rotational magnetic field from a stator outside a patient's body. The stator generates both torque to rotate the inside rotor dome in all three dimensions, and force to serve as an anchoring...
This paper reviews recent technical trends in variable flux motors. Permanent magnet motor is a major component to realize high torque density with keeping high efficiency. However, when high speed revolution is required for further miniaturization, as well as the large torque in the low speed region, the flux yielded by the permanent magnet encounters a serious trade-off, i.e. the former needs less...
Today many medical interventions are performed minimally-invasive, with great benefits for the patient. The image is taken with an endoscope and displayed on a screen. Present Chip-on-the-Tip Endoscopes do not offer an autofocus or an optical zoom, which improves image quality as well as flexibility whereas these are standard techniques in most other applications, for example consumer cameras. Electromagnetic...
This paper presents operation and control of a Squirrel Cage Induction Generator (SCIG) to generate power from an oscillating point absorber based wave energy conversion (WEC) system. The oscillating point absorber buoy is assumed to be connected with the SCIG through a rack and pinion gear arrangement, thus converting the linear motion of the buoy to rotary motion of the generator. Proper gear ratio...
In this paper, a novel 12/14 bearingless switched reluctance motor (BLSRM) is investigated. For the conventional 12/14 BLSRM, there is only a small conduction range for positive torque generation. In order to solve this problem, shifting stator pole technology is applied in the proposed structure. It is good for increasing the output torque and simplifying the control circuit. However, the proposed...
Linear Switched Reluctance Motor (LSRM) is a potential candidate of traditional rotary-linear motors on many industrial applications. In this paper, a LSRM design procedure is presented to obtain the main dimensions of a LSRM. By adjusting some dimensions detailed, performance of a LSRM can be improved based on the main dimensions from the design procedure. The generated force is improved by using...
According to the study of traditional cylindrical PM motor, it is generally acknowledged that the electromagnetic radial force is the root cause of electromagnetic vibration and noise, However, for round square PM motor, the tangential force is the main cause of electromagnetic vibration and noise besides radial force, for its geometry structure and electromagnetic characteristic. This paper deduces...
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