• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.488-492
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• 2004

In this paper, the design of a speed sensorless vector control system for induction motor is performed by using a new sliding mode technique based on current model flux observer. A current and flux observer based on the current estimation error is constructed. The proposed current observer includes a sliding mode function, which is derivative of the flux. That is, sliding mode observer which allows the estimation of both the rotor speed and flux based on the measurement of motor terminal quantities, would be proposed. And, a synergetic speed controller using the estimated speed signal is designed to stabilize the speed loop. Simulation results are presented to confirm the theoretical analysis, and to show the system performance with different observer gains and the influence of the motor parameter.

• Journal of Advanced Marine Engineering and Technology
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• v.23 no.3
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• pp.369-378
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• 1999

This paper presents position control of an electro-hydraulic servo system whoch is operated by four 2-2way high speed on-off valves with either PWM PID control method or sliding mode control method, The advantages of using high speed on-off valves instead of electo-hydraulic servo valves or electro-hydraulic proportional valves are low price robustness for oil contamination and direct control without a D/A converter. The system consists of load cylinder inertia car potentiometer and external load cylinder. The experiments were carried out under several conditions and the results were compared. As a result the sliding mode method has shown good control performance and the robust and stable positioning of the elector-hydraulic servo system can be achieved accurately.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.1
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• pp.34-39
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• 2013

This paper proposes the implementation of robust fuzzy controller for designing intelligent wind farm and mitiagating the fluctuation of wind power generator. The existing researches are limited to individual wind turbine with variable speed so that it is necessary to study the multi-agent wind turbine power system. The scopes of these studies include from the arrangements of each power turbine to the control algorithms for the wind farm. For solving these problems, we introduce the composition of intelligent wind farm and use the T-S (Takagi-Sugeno) fuzzy model which is suitable for designing fuzzy controller. The control object in wind farm enables the minimizing the fluctuation of wind power generator. Simulation results for wind fram which is modelled as mathematically are demonstrated to visualize the feasibility of the proposed method.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.374-379
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• 2001

In this paper, a novel design algorithm of speed controller for an Induction motor with the inertia variation is proposed. The main contribution of our work is a very robust, reliable and stable procedure for setting of the PI gains against the specified range of the inertia variation of an induction motor using Kharitonovs robust control theory. Therefore, the basic segment of controller design, the variation of induction motor inertia is estimated by the RLS (Recursive least square) method. PI based speed controller is widely used in industrial application for its simple structure and reliable performance. In addition the Kharitonov robust control theory is used for verification stability of closed-loop transfer function. The performance of this proposed design method is proved by digital simulation and experimentation with high performance DSP based induction motor driving system.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.4
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• pp.435-440
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• 2000

The speed control system of diesel engine is considerably nonlinear. Therefore, a countermeasure such as gain scheduling used to be incorporated to compensate this nonlinearity. On the other hand, it is said that fuzzy control is very robust against nonlinearity. But it is difficult to get a satisfactory response with only fuzzy control in real system. In this paper authors design a fuzzy-PI controller for the speed control of Medium diesel engine and carry out experiments with dedicate system implemented by Intel 80916KC to real diesel engine, Deawoo MAN 6Cyl., 1800rpm driving 3$\psi$220V, 150KW generator. We confirm the effectiveness of proposed control system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.11
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• pp.69-75
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• 2009

In this paper, a self-tuning regulator for a speed control of a permanent magnet type stepping motor is proposed. The self-tuning theory provides a nonlinear modeling of a stepping motor drive system and can provide the controller with information regarding the reference variation and parameter variation of the stepping motor through the on-line estimation. The proposed self-tuning regulator organize the positive feedback loop and IP(Integral-Proportional) type. Therefore, the proposed self-tuning regulator has a robust control capabilities during dynamic operation. The availability of the proposed controller is verified through experimental results.

• Journal of Power Electronics
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• v.12 no.1
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• pp.75-82
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• 2012

Elimination of rotor position sensors mechanically coupled with the rotor shaft is attractive to variable speed drives primarily due to increased system reliability and cost reduction. In this regard, search for a simple and robust position sensorless control has been intensified in past few years specifically for low-cost, high-volume applications such as home appliances. This paper describes a new parameter insensitive position sensorless control for switched reluctance motor (SRM) drives satisfying such a need in this market segment. Two consecutive switch-on times of the controllable switch in hysteresis current control are compared to estimate the rotor position and speed. The proposed sensorless control algorithm is very simple to implement since it does not depend on extensive computation or any additional hardware. In addition, the proposed method is robust in that its dynamic performance is least affected by system parameter variations. The proposed approach is demonstrated on a single-controllable-switch-converter-driven SRM with two-phases that lends itself to a system with low cost and compact packaging which comes close to the intended applications. Analysis and simulation results followed by experimental verification are presented to demonstrate the feasibility of the proposed sensorless control method.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.11
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• pp.860-867
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• 2003

This paper presents a systematic method measuring a velocity disturbance to design the robust seek loop system of optical disk drives. The velocity disturbance caused by the rotation of a disk has a greater influence on the performance of the seek control loop as the rotational speed increases. Thus, it needs to measure the extent of the velocity disturbance and design the seek control loop based on the measured data. The measurement method of the velocity disturbance is a real-time . method using a measurable velocity and a velocity controller output and is a robust method considering actuator uncertainties. The loop gain adjustment algorithm is introduced to compensate for the actuator uncertainties. The proposed method is implemented by an experimental digital system and is evaluated through an experiment.

• Journal of Power Electronics
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• v.10 no.4
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• pp.382-387
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• 2010

This paper presents a novel design method for determining the PID gains of a speed controller for a servo system compensating variations in bandwidth at a low speed. The variations in bandwidth of a speed controller are measured at a low speed and the relationship between the bandwidth and the damping ratio are verified by determining the location of the closed loop pole. The proposed algorithm uses the z-transform of a plant and speed controller and applies the time-varying sampling method for determining the PID gains of the speed controller at low speed. The magnitude and the phase condition are considered for finding a suitable control gain. The usefulness and effectiveness of the proposed method is demonstrated through experimental results such as low speed control and robust disturbance responses.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.5
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• pp.899-906
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• 2020

Motor control requires robust and precise control performance even in the presence of errors in the mathematical model of the motor and disturbances acting on the motor. For robust and precise control, a disturbance observer was designed to estimate the load fluctuation and applied to a back-stepping controller designed as a nominal system. The control performance of the designed system was verified by applying it to the 120 [W] Brushless Direct Current Motor. As a result of the position control and speed control, the disturbance is overcome from the steady state error converges to zero, and asymptotically stable results can be confirmed.