Methods of detent force reduction in linear synchronous motors

Jeans, C.G.; Cruise, R.J.; Landy, C.F.

doi:10.1109/iemdc.1999.769139

Cited by 11 publications

(4 citation statements)

References 2 publications

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“…slotting effects, end effects or coil topology. They can be reduced by methods such as applying non-sinusoidal currents teJansen:EMD03, skewing (Jeans et al, 1999) or using quasi-Halbach topologies (Halbach, 1980;Meessen et al, 2008). Surface charge modeling enables very fast and accurate calculation of key properties such as inductance, EMF and flux leakage in slotless drives.…”

Section: Application To Skewed Linear Machinesmentioning

confidence: 99%

3D analytical field calculation using triangular magnet segments applied to a skewed linear permanent magnet actuator

Janssen

Paulides

Lomonova

2010

COMPEL - The International Journal for Computation and Mathematics in Electrical and Electronic Engineering

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Purpose -The purpose of this paper is to present novel analytical expressions which describe the 3D magnetic field of arbitrarily magnetized triangular-shaped charged surfaces. These versatile expressions model that the field of triangular-shaped permanent magnets (PMs) are very suitable to model skewed slotless machines. Design/methodology/approach -The analytical 3D surface charge method is normally used to provide field expressions for PMs in free space. In this paper, the analytical surface charge integrals are analytically solved for charged right-triangular surfaces. The resulting field is compared with that obtained by finite element modeling (FEM) and subsequently applied in two examples. Findings -The comparison with FEM shows that the 3D analytical expressions are very accurate and exhibit very low-numerical noise. These fast-solving versatile expressions are therefore considered suitable to model triangular-shaped or polyhedral-shaped PMs.Research limitations/implications -The surface charge method assumes that the relative permeability is equal to 1 and therefore soft-magnetic materials need to be modeled using the method of images. The PMs are assumed to be ideal in terms of homogeneity, magnetization vector, permeability, demagnetization, and geometrical tolerances. Practical implications -Many applications, such as the subclass of slotless synchronous linear actuators with a skewed PM structure and planar magnetic bearings, are very suitable to incorporate this modeling technique, since it enables the analysis of a variety of performance data. Originality/value -As an addition to the common 3D analytical field expressions for cuboidal or cylindrical PMs, this paper presents novel expressions for magnets having triangular surfaces.

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Section: Application To Skewed Linear Machinesmentioning

confidence: 99%

3D analytical field calculation using triangular magnet segments applied to a skewed linear permanent magnet actuator

Janssen

Paulides

Lomonova

2010

COMPEL - The International Journal for Computation and Mathematics in Electrical and Electronic Engineering

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show abstract

“…Contamination or small particles with different sizes and material properties in the contact surfaces also change the contact condition between two surfaces and induce more complicated forces . As for motors, the cogging force (which is also known as detent force ), is produced by interaction between coil and magnets. This periodic wave‐like force degrades tracking accuracy, and the speed ripple makes the steady state velocity difficult to achieve, especially in a low speed regime.…”

Section: Introductionmentioning

confidence: 99%

Linear Model‐based Feedforward Control for Improving Tracking‐performance of Linear Motors

Li¹,

Tien²

2014

Asian Journal of Control

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The main purpose of this article is to propose a linear model-based approach for improving the tracking performance of linear motors. In particular, P-and PI-controllers, augmented with a linear-model-based feedforward controller and disturbance observer (DOB), were utilized in this research. Experimental results show that the feedforward controller can substantially reduce the phase-delay problem resulting from the limitation of closed-loop bandwidth. In addition, the DOB can reject nonlinear behaviors to keep a motor-system close to our nominal linear model. Compared with the results of using P-and PI-controllers only, tracking errors were reduced from 4.44% to 0.67% of the desired trajectory. Therefore, the proposed method provides a solution for improving the tracking performance of linear motors.

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“…In the practical PMLSM control system, the classical PID control is still the main control method. However, as linear motor adopts direct drive, many kinds of external disturbances will effect on the linear motor directly, which depresses the accuracy of linear motor control seriously [2]- [5]. Increasingly, the shortcomings of the classical PID control become obvious: 1) The method of acquiring errors is unreasonable; 2) Calculation of the error differential signal tends to amplify noise; 3) The combination of proportional, integral, differential linear is not optimal.…”

Section: Introductionmentioning

confidence: 99%

A Nonlinear Controller for PMLSM Control System Based on Tracking Differentiator

Yan

Chen

2011

AMR

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This paper introduces tracking differentiator based on the classical PID control in order to arrange the transitional process according to the set point and control system parameters, solving the contradictions between speed and overshoot of the manipulated variable in the traditional PID control. At the same time, tracking differentiator provide an effective method of calculating differential with low noise amplification. Nonlinear PID controller adopts a nonlinear combination of error, error differential and error integral to calculate the controlled variable in a very effective way. Applying this kind of nonlinear PID controller to the permanent magnet linear synchronous motor control system , the experimental results show that PMLSM can follow the speed command quickly in no overshoot, and has strong robustness, good static and dynamic characteristics.

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Methods of detent force reduction in linear synchronous motors

Cited by 11 publications

References 2 publications

3D analytical field calculation using triangular magnet segments applied to a skewed linear permanent magnet actuator

3D analytical field calculation using triangular magnet segments applied to a skewed linear permanent magnet actuator

Linear Model‐based Feedforward Control for Improving Tracking‐performance of Linear Motors

A Nonlinear Controller for PMLSM Control System Based on Tracking Differentiator

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