• Journal of Mechanical Science and Technology
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• v.18 no.3
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• pp.337-346
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• 2004

The control scheme using fuzzy modeling and Parallel Distributed Compensation (PDC) concept is proposed to provide asymptotic tracking of a reference signal for the flexible joint manipulators with uncertain parameters. From Lyapunov stability analysis and simulation results, the developed control law and adaptive law guarantee the boundedness of all signals in the closed-loop multi-input/multi-output system. In addition, the plant state tracks the state of the reference model asymptotically with time for any bounded reference input signal.

• Journal of Power Electronics
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• v.10 no.6
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• pp.694-701
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• 2010

In this paper an effective direct torque control (DTC) and stator flux control is developed for a quasi six-phase induction motor (QIM) drive with sinusoidally distributed windings. Combining sliding-mode (SM) control and adaptive input-output feedback linearization, a nonlinear controller is designed in the stationary reference frame, which is capable of tracking control of the stator flux and torque independently. The motor controllers are designed in order to track a desired second order linear reference model in spite of motor resistances mismatching. The effectiveness and capability of the proposed method is shown by practical results obtained for a QIM supplied from a voltage source inverter (VSI).

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.5
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• pp.531-537
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• 2015

In order to maximize power output from the solar panels, one needs to keep the panels aligned with the sun. So solar tracker having high reliability must be designed. This paper cares about the design and evaluation of a two-axis solar tracker system based on fuzzy logic control with LabVIEW. The research focus on planning mechanical parts, making an intelligent controller which controls and monitors all parameters via user interface implemented of a fuzzy decision support system for control of photovoltaic panel movement. We also develop a real solar tracker system and analyze the influence indexes such as environment, weather, season, and light condition. The solar tracker is tested in real condition and all parameters related to the system operation are recorded and analyzed. The developed solar tracking system got a much higher efficiency about 38 % compare to fixed solar panel although the weather condition is affected a lot to the solar panel. So we confirmed the our auto tracking system is more effective and can allow more energy to be produced.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.956-959
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• 1996

In this study, we propose a neuro-genetic controller combined with a linear controller in parallel to improve the tracking performance of the Line of Sight(LOS) stabilization system and reject the effect of disturbances. A Genetic Algorithm(GA) is used to optimize weights of the neuro-genetic controller since this algorithm can search a global minimum without derivatives or other auxiliary knowledge. The LOS system is very complex and has limited measurable output data. Under these specific circumstances GA solves many problems that other training methods have. Computer simulation results show that the, proposed controller makes better tracking response and rejection of disturbance than a linear controller.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.382-383
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• 2018

To increase the efficiency of a wind energy conversion system (WECS), the maximum power point tracking (MPPT) algorithm is usually employed. This paper proposes an optimal MPPT algorithm which tracks a sudden wind speed change condition fast. The proposed method can be implemented without the prior information on the wind turbine parameters, generator parameters, air density or wind speed. By investigating the directions of changes of the mechanical output power in wind turbine and rotor speed of the generator, the proposed MPPT algorithm is able to determine an optimal speed to achieve the maximum power point. Then, this optimal speed is set to the reference of the speed control loop. As a result, the proposed MPPT algorithm forces the system to operate at the maximum power point by using a three-phase converter. The simulation results based on the PSIM are given to prove the effectiveness of the proposed method.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.496-499
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• 2006

The solar cells should be operated at the maximum power point because its output characteristics are greatly fluctuate on the variations of insolation, temperature and loads. To obtain maximum power from solar cell, photovoltaic system cell power system usually requires maximum power point tracking controller. This paper propose Maximum power point tracking method using zero slope of differential value of maximum power. The power compare method traces to maximum power point rapidly but oscillate on the maximum power point largely, when quantity insolation variation is big. The power compare method is traces to maximum power point slowly but oscillate maximum point on the maximum power point smally, when quantity insolation variation is small. To solve two problem of the power compare method, designed zero slope of differential value of maximum power.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.5
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• pp.963-969
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• 2006

In this study, we designed a digital fuzzy logic controller based on FPGA and microprocessor for MPPT of the solar power generation system. A fuzzy algorithm to control the power tracking function of a boost converter has been built into the FPGA, and applied to the small scaled solar power generation system. The embodied controller showed a stable operation characteristic with the small output voltage ripple for the intensity change of solar radiation. This result proves that the implementation of the power tracking controller using FPGA is an effective way compared to the existing one using microprocessors.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.1
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• pp.75-79
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• 2012

Maximum power point tracking(MPPT) techniques are used in photovoltaic systems to maximize the PV array output power by tracking continuously the maximum power point which depends on panels temperature and on irradiance conditions. This paper proposes a variable step size MPPT algorithm which can improve the MPPT speed and accuracy. Depending on insolation and temperature, the MPPT controller gives optimized step size. The effectiveness of the proposed system is verified thorough PSIM simulation and experiments on a 50[W] prototype. The experimental results confirm that the PV power of the improved P&O method is higher than that of the traditional P&O method.

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.615-619
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• 2009

There are many increasing demands for efficient high power density of auxiliary power unit(APU) for high speed traction application. Many techniques have been proposed to measure the voltage flicker on the traditional pulse width modulation(PWM) inverter. This paper proposes a novel functionality of the static inverter on the APU to mitigate the voltage flicker and regulate the output voltage. A new control algorithm for the inverter based on the Hilbert transform(HT) is presented. The HT is employed as an effective technique for tracking the voltage flicker levels in APU systems. Simulation results are provided to verify the tracking capabilities of the HT and to evaluate the performance of the proposed DG interface for multi-function operation.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.181-184
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• 1996

This paper deals with the design problem of model reference adaptive controllers for MIMO plants with unknown orders. A design scheme for an adaptive control system based on CGT theorem, which has hierarchical structures derived from backstepping strategies, is proposed for MIMO plants with unknown orders but with known relative MacMillan degrees(relative degrees for SISO plants). It is also shown that all the signals in the resulting control system are bounded, and that the asymptotic tracking is achieved in the case where reference inputs are step.