• Journal of Electrical Engineering and Technology
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• v.7 no.1
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• pp.34-45
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• 2012

In the present paper, the mover speed control of a linear induction motor (LIM) using a sliding mode control design is proposed, considering the end effects. First, the indirect field-oriented control LIM is derived, considering the end effects. The sliding mode control design is then investigated to achieve speed- and flux-tracking under load thrust force disturbance. The numerical simulation results of the proposed scheme present good performances in comparison to that of the classical sliding mode control.

• Proceedings of the KIPE Conference
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• 2002.11a
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• pp.7-11
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• 2002

This paper proposes an APF(Active Power Filter) with WRIM(Wounded Rotor Induction Motor) controlled by sliding mode which can compensate harmonic currents generated in a power system. As non-linear loads increase gradually in industry fields, harmonic current generated In the electric power network system also increases. Harmonic current makes a power network current distorted and generates heat, vibration and noise In the power machinery, Many approaches have been applied to compensate harmonic currents generated in the power system. Among various control strategy, in this paper, a sliding mode controlled systems is designed and evaluated. This is a flywheel compensator based on secondary excitation of WRIM(wounded rotor induction motor) with SMC(sliding mode controller). The proposed system uses a flywheel as an energy storage device. The designed control scheme is verified through simulation.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.29-32
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• 1989

This paper proposes new position control method for DC servo motor by PI controller adopting sliding mode control. By adding sliding mode controller to conventional PI controller good robustness is obtained with good transient response and no steady state error which are merits in PI controller. In order to use microprocessor for digital control the principles of sliding mode control conventionally explained in continous-time system are extended to discrete-time system.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.1
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• pp.39-46
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• 1991

In the VSS control, the trajectories with a conventional sliding surface have a reaching phase which is an interval from the initial state to the first touching of the sliding surface. Since the sliding mode control can not be realized in a reaching phase, the trajectories may be sensitive to the disturbances and parameter variations. A simple nonlinear sliding surface is proposed to improve the robustness in a reaching phase. The position control of a PM DC servo motor using a new sliding surface is carried out and is compared to the one using the conventional surface. The sliding mode occurs in entire trajectories with the proposed new sliding surface and the improved robustness is obtained.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1679-1680
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• 2008

DC motor has been widely used in industrial applications, because the performance is excellent on the speed and position system. However, when a system has parameter uncertainty, it is very difficult to guarantee its performance. Sliding mode control is robust for parameter uncertainty. However conventional sliding mode control can not have the properties of PID controller because its sliding surface has lower order dynamics than the original system. In this paper the sliding surface design method is proposed by using virtual state for DC motor speed control. Its design is based on the augmented system whose dynamics have one higher order than that of the original system. As a result, in spite of the parameter uncertainty, the proposed sliding surface can have the same dynamic of nominal system controlled by PID controller. And the reaching phase is removed by setting an initial state which makes the initial sliding surface equal to zero.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.571-575
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• 1989

A position control system of D.C. Servo motor based on discrete variable structure system with sliding mode is presented. The sliding mode has been designed for a continuous system, but it is often realized in digital fashion because the complex switching logic can be easily carried out. In digital control system, the ideal sliding mode does not occur since the structure can't be switched during sampling interval. However, there can be exist a motion which is confined to a regoin including the sliding surface and proceeds to the origin along the surface. This notion is called quasisliding mode. In this paper, we introduce this control scheme to the D.C. Servo motor position control in order to reduce the chattering phenonenon.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.10
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• pp.587-594
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• 2005

An adaptive observer for rotor resistance is designed to estimate rotor flux for the a-b model of an induction motor assuming that rotor speed and stator currents are measurable. A singularly perturbed model of the motor is used to design an Adaptive sliding mode observer which drives the estimated stator currents to their true values in the fast time scale. The adaptive observer on the sliding surface is based on the equivalent switching vector and both the estimated fluxes and the estimated rotor resistance converge to their true values. A speed controller considering the effects of parameter variations and external disturbance is proposed in this paper. First, induction motor dynamic model at nominal case is estimated. based on the estimated model, speed controller is designed to match the prescribed speed tracking specifications. Then a dead-time compensator and a robust controller are designed to reduce the effects of parameter variations and external disturbances. the desired speed tracking control performance can be preserved under wide operating range, and good speed load regulating performance. Some simulated results are provided to demonstrate the effectiveness of the Proposed controller.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.74-76
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• 2009

In this paper, search method and sliding mode observer are developed for efficiency optimization of induction motor. The proposed control scheme consists of efficiency controller and adaptive backstepping controller. A search controller for which information of input of fuzzy controller is included in efficiency controller that uses a direct vector controlled induction motor. The search controller is based on the "Rosenbrock" method and finds the flux level at the minimum input power of induction motor. Once this optimal flux level has been determined, this information is utilized to update the rule base of a fuzzy controller A sliding mode observer is designed to estimate rotor flux and an adaptive backstepping controller is also used to compensate for mechanical uncertainties in the speed control of induction motor. Simulation results are presented to validate the proposed controller.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.4
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• pp.402-410
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• 2019

This paper deals with the disturbance observer (DOB) based sliding mode control (SMC) for a DC motor to control motor rotating speed precisely and to ensure strong robustness against disturbance including load torque and parameter variation. The reason of steady state error in speed on conventional SMC without DOB is analyzed in detail. Especially, the suggested DOB is designed to prevent measuring noise and harmonics caused by derivative operation on rotating speed. The control performance of the DOB based SMC is evaluated by the various simulations. The simulation results showed that the DOB based SMC had more robust performance than the SMC system without DOB. Especially, precise speed control was possible even though motor parameter variation and load torque was added to the system.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.3
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• pp.249-255
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• 2010

The paper proposes a new type of robust speed control strategy for permanent magnet synchronous motor by using PD-sliding mode hybrid control. The PD control has a good performance in the transient region while the sliding mode controller provides the robustness against system uncertainties. Taking advantages of the two control strategies, the proposed control method utilizes the PD control in the approaching region to the sliding surface and the sliding mode control near at the sliding surfaces. The chattering problem of the sliding mode controller is eliminated by applying the saturation function for the switching function of the sliding mode control. The stability of the sliding mode control is verified by using Lyapunov function with the proper selection of variable gains. It is shown that with this simple switching algorithm, stability of the overall hybrid control system is ensured. Through the simulations, the PD-sliding mode algorithm is shown to have a good performance in the transient response as well as being robust against disturbances. The robustness of the PD-sliding mode algorithm is further demonstrated against various external disturbances in the real experiments of SPMSM motor control.