• Journal of Power Electronics
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• v.10 no.3
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• pp.300-305
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• 2010

This paper presents a two Hall sensor method for rotor angle detection in permanent magnet synchronous motors (PMSM). To minimize the implementation complexity, the system is designed to measure the edge field of permanent magnet pieces. However, there are nonlinearities in the measured values of the edge field. In this work, an angle correction algorithm is proposed, and the improvements in accuracy are verified through experiments. Finally, a field orientation controller is constructed with the proposed angle detection algorithm.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.4B no.1
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• pp.20-23
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• 2004

BLDCMs are widely used in many industries. In certain specialized areas, they need to have high efficiency, high power rate and produce a low volume of noise, etc. In this study, a new type of slotless BLDCM is proposed that has no cogging torque, low iron loss and low volume as compared to commonly used BLDCMs. With a high performance magnet and coreless compact winding structure similar to those employed in linear synchronous motors, motor volume is reduced. The proposed motor has been put been through various experiments arid has demonstrated acceptable results for industry applications.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.1
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• pp.53-60
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• 2015

For high-accuracy position control of a linear motor, it has been proposed a nonlinear controller including a synchronization algorithm. Linear motors are easily affected by force ripple, friction, and parameter variations because there is no mechanical transmission to reduce the effects of model uncertainties and external disturbances. Synchronization error is also caused by skew motion, model uncertainties, and force disturbance on each axis. Nonlinear effects such as friction and ripple force are estimated and compensated for. The synchronization algorithm is used to reduce the synchronous error of the two side pillars. The performance of the controller is evaluated by computer simulations.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.4
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• pp.273-278
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• 2019

This study proposes a method for improving the overmodulation performance of a three-phase inverter to obtain an enhanced output torque for the AC motors. In the inverter-fed AC motor drives, the output torque of the motor can be enhanced by utilizing the overmodulation region as well as the linear modulation regions of the inverter. The overmodulation method is used for this overmodulation operation of the inverter. However, the voltage gain, the ratio of the output voltage of the inverter to the reference voltage achieved by the conventional overmodulation methods becomes nonlinearly smaller than unity. Therefore, the effect of improving the output torque of the AC motors is insignificant even when the overmodulation region is utilized. In this study, we propose a method that improves the overmodulation performance of the inverter by compensating the limited amount of the reference voltage in the overmodulation operation to enhance the output torque of the AC motors. The effectiveness of the proposed method is verified through the simulations and experiments with an 800 W permanent magnet synchronous motor.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.9-12
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• 2003

Brushless do motors have been replacing brush type motors in machine tool and robotics applications over the last number of years This Paper deals with the design and application of the slot-less permanent magnet synchronous motor (PMSM). The slot-less PMSM eliminates rotational cogging torque due to permanent magnet preferred positions decreases core loss and thus increases efficiency, provides excellent torque-to-volume and power-to-volume ratios, and has a linear current versus torque relation. The PMSM with slot-less stator is designed and manufactured, which will be used for high speed and high efficiency application such a medical instruments.

• International Journal of Control, Automation, and Systems
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• v.4 no.1
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• pp.1-9
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• 2006

This paper presents the modeling and multivariable feedback control of a novel high-precision multi-dimensional positioning stage. This integrated 6-degree-of-freedom. (DOF) motion stage is levitated by three aerostatic bearings and actuated by 3 three-phase synchronous permanent-magnet planar motors (SPMPMs). It can generate all 6-DOF motions with only a single moving part. With the DQ decomposition theory, this positioning stage is modeled as a multi-input multi-output (MIMO) electromechanical system with six inputs (currents) and six outputs (displacements). To achieve high-precision positioning capability, discrete-time integrator-augmented linear-quadratic-regulator (LQR) and reduced-order linearquadratic-Gaussian (LQG) control methodologies are applied. Digital multivariable controllers are designed and implemented on the positioning system, and experimental results are also presented in this paper to demonstrate the stage's dynamic performance.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.1
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• pp.89-97
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• 2008

Chaotic behavior in motor systems is undesired dynamics in real-time implementation since the speed is oscillated in a wide range and the torque is changed by a random manner. We present an adaptive control approach for time-varying permanent-magnet synchronous motors (PMSM) with chaotic phenomenon. We consider that its parameters are changed randomly within certain bounds. First, a nonlinear system model of a PMSM is transformed to derive a nominal linear control strategy. Then, an auxiliary control for compensating real-time control error occurred by system perturbation due to parameter change is designed by using Lyapunov stability theory. Numerical simulation is accomplished for evaluating its efficiency and reliability comparing with the traditional control method. Additionally, we test our control method in real-time motor experiment including a PSoC based drive system to demonstrate its practical applicability.

• Journal of Power Electronics
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• v.16 no.5
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• pp.1773-1780
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• 2016

This paper proposes a wide air-gap control method for the multi-module permanent magnet linear synchronous motor (MM-PMLSM) based on independent vector control. In particular, the MM-PMLSM consists of symmetrical multi-module and multi-phase structures, which are basically three-phase configurations without a neutral point, unlike conventional three-phase machines. In addition, there are no additional magnetic levitation windings to control the normal force of the air-gap between each stator and mover. Hence, in this paper, a dq-axis current control applying a d-q transformation and an independent vector control are proposed for the air-gap control between the two symmetric stators and mover of the MM-PMLSM. The characteristics and control performance of the MM-PMLSM are analyzed under the concept of vector control. As a result, the proposed method is easily implemented without additional windings to control the air-gap and the mover position. The effectiveness of the proposed independent vector control algorithm is verified through experimental results.

• Journal of Magnetics
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• v.18 no.3
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• pp.352-356
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• 2013

Recently, the stationary discontinuous armature, Permanent Magnet Linear Synchronous Motor (PM-LSM), was suggested as a driving source for long-distance transportation system. However, as these motors arrange armatures discontinuously, an edge occurs thereby leading to a cogging force. This works as a factor that hinders the acceleration and deceleration that takes place when movers enter into and eject from armatures. Therefore, in this study, the installation of auxiliary teeth on the edge of the armature of PM-LSM is suggested in order to reduce the cogging force caused by the edge when the armature is placed in a discontinuous arrangement. Auxiliary teeth are optimally designed by a 2-D numerical analysis using the finite element method was performed to generate the optimum design of the auxiliary teeth. The validity of the study was confirmed through the comparison of the cogging force induced at the edge in respect to the design parameter using the basic model.

• Journal of Electrical Engineering and Technology
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• v.8 no.6
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• pp.1439-1450
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• 2013

This paper investigates a robust neuro-fuzzy control (NFC) method which can accurately follow the speed reference of an interior permanent magnet synchronous motor (IPMSM) in the existence of nonlinearities and system uncertainties. A neuro-fuzzy control term is proposed to estimate these nonlinear and uncertain factors, therefore, this difficulty is completely solved. To make the global stability analysis simple and systematic, the time derivative of the quadratic Lyapunov function is selected as the cost function to be minimized. Moreover, the design procedure of the online self-tuning algorithm is comparatively simplified to reduce a computational burden of the NFC. Next, a rotor angular acceleration is obtained through the disturbance observer. The proposed observer-based NFC strategy can achieve better control performance (i.e., less steady-state error, less sensitivity) than the feedback linearization control method even when there exist some uncertainties in the electrical and mechanical parameters. Finally, the validity of the proposed neuro-fuzzy speed controller is confirmed through simulation and experimental studies on a prototype IPMSM drive system with a TMS320F28335 DSP.