• Journal of the Earthquake Engineering Society of Korea
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• v.21 no.5
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• pp.215-226
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• 2017

In this paper, an experimental study was carried out for vibration control of cable bridges with structurally flexible characteristics. For the experiment on vibration control, a model bridge was constructed by reducing the Seohae Grand Bridge and the shear type MR damper was designed using the wind load response measured at Seohae Grand Bridge. The shear type MR damper was installed in the vertical direction at the middle span of the model bridge, and dynamic modeling was performed using the power model. The tests of the vibration control were carried out by non-control, passive on/off control and Lyapunov control method on model bridge with scaled wind load response. The performance of the vibration control was evaluated by calculating absolute maximum displacement, RMS displacement, absolute maximum acceleration, RMS acceleration, and size of applied power using the response (displacement, acceleration, etc.) from the model bridge. As a result, the power model was effective in simulating the nonlinear behavior of the MR damper, and the Lyapunov control method using the MR damper was able to control the vibration of the structure and reduce the size of the power supply.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.743-746
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• 1998

In this paper, we developed an outdoor augmented reality system which has remote real scences acquisition ability. The real scenes acquisition system consists of image acquisition system, tracking system, wireless data transceiver and power supply. Tracking system that consists of Tans Vector and RT-20 measures a position and attitude of the CCD camera that attached at the remote control helicopter. Wireless data transceiver system is utilized for data transmission of remote system that of attitude, position information, andreal scenes data that acquired by the CCD camera. Maximum propelling power of remote control helicopter is 15Kg, so we used 7.2V li-ion cell as a power supply for system minimize. As the results of experiment, the developing system presented application possibility of remote information acquisition system such as construction simulation & estimation, broadcasting, tour guide.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.2
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• pp.194-200
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• 2006

The SoC and digital technology development recently enabled the emergence of information devices and control devices because the SoC presents many advantages such like lower power consumption, greater reliability, and lower cost. However, it is nearly impossible to use the SoC without operating systems because the SoC is included with many peripherals and complex architecture. It is required to use embedded operating systems and real-time operating systems may be used as an embedded operating system. So far, real-time operating systems are widely used to implement a Real-Time system since it meets developer's requirements. However, real-time operating systems have disadvantages including a lack of standards, expensive development, and license. Embedded Linux is able to overcome their disadvantages. In this paper, the implementation of control system platform for a mobile robot using real-time Embedded Linux is described. As a control hardware system platform, XScale board is used. As the real-time Embedded Linux, RTAI is adopted which is open source and royalty free, and supports various architectures and real-time devices, such like real-time CAN and real-time COM. This paper shows the implementation of RTAI on XScale board that means the porting procedure. We also applied the control system platform to the mobile robot and compared the Real-Time serial driver with non real-time serial driver. Experimental results show that that using RTAI is useful to build real-time control system with powerful functionalities of Linux.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2001.05a
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• pp.192-196
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• 2001

These days, most of electric power facilities need high stability. Therefore integrated system has been required to monitor and control electronic power distribution system in fields at all times when the interruption of electric power has occurred. To construct this system, unit that convert and process the input signal from fields needed. And for control and monitoring from remote place MMI software is required. Lastly network equipments are required for real-time communications. So, in this paper, units for control and monitoring of emergency power generator and for electric power monitoring in normal electric power and interruption of electric power are developed. Also integrated remote system for monitoring in remote is developed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.10
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• pp.1455-1460
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• 2014

Wind turbine generators were designed on general regulations of wind condition. At real situations, it could be different from the design conditions. There are many control methods and definitions of transient region, because an efficient wind turbine generator control logic is the important matter in generator performance and annual energy production at real conditions. In this document, the power generation sensitivity for wind speed and turbulence intensities was defined to know the sensitive transient region. Wind conditions are applied for the ranges of 7~10m/s mean wind speed and 14~20% turbulence intensity. The sensibility of HR-D86 wind generator was increased in transient region(8~10m/s) on power curve diagram through a torque control to a pitch control. And then GH-bladed simulations was performed for performance analysis of the torque mode switching in transient region on 2MW direct drive wind generator(HR-D86) which is designed IEC class II for onshore. Through the sensitivity and performance analysis, the sensitivity for real wind condition could be the performance index for an wind generator. And the torque mode switching in transient region can increase the mean power generation on HR-D86 wind turbine generator.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.36 no.10
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• pp.695-702
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• 1987

Nowadays as the power systems have been more complicated and have grown to ultra high voltage, it requires a accurate and high speed relaying scheme to improve the reliability and stability of power systems for a harmonious power supplying. For this purpose voltage and current have to be measured at the location of the protective device and the short circuit impedance must be determined. This paper presents the application methods and some results of digital distance relaying scheme which is based upon the theouy of real-time symmetrical components. Usually the symmetrical component have been used to solve the transient systems as well as the steady state systems under unbalanced systems. But, real-time symmetrical component frequently have not been applied to on-line control region of the large power system. We have tried to apply this method to deal with the various type of faults on artificial transmission line. And experimental results demonstrate the validity of the proposed techniques. Therefore, this study is expected that it is contributed to improve the reliability of power supplying, searching for the fault location rapidly and exactly in power system.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.880-883
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• 1998

In this paper, sensitivity based approach to estimate BITC(bilateral interchange transfer capacity) considering the real power flow control function of FACTS device is presented. The real power flow setting of the FACTS device is adjusted so that it transfer the power flow from the first violation point of transmission capacity to other transmission lines in the power system, thus allowing more power to be transferred from the specified generator bus to the specified load bus. The transfer between the two bus locations is increased from this new operating condition until a violation of transmission capacity limits occurs or until the setting of the FACTS device can no longer be adjusted. The proposed algorithm is illustrated using examples of small and real life power system.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.5
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• pp.404-411
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• 2020

Inductive power transfer (IPT) systems for electric vehicles generally require zero phase angle (ZPA) frequency tracking control to achieve high efficiency. Current sensors are used for ZPA frequency tracking control. However, the use of current sensors causes several problems, such as switching noise, degrading control performance, and control complexity. To solve these problems, this study proposes ZPA frequency tracking control without current sensors. Such control enables ZPA frequency tracking without real-time control and achieves stable zero voltage switching operation closed to ZPA frequency within all coupling coefficient and load ranges. The validity of the proposed control algorithm is verified on LCCL-S topology with a 3.3 kW rating IPT experimental test bed. Simulation verification is also performed.

• Journal of Power Electronics
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• v.14 no.1
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• pp.74-81
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• 2014

In this study, a brain emotional learning-based intelligent controller (BELBIC) is developed for the speed control of an interior permanent magnet synchronous motor (IPMSM). A novel and simple model of the IPMSM drive structure is established with the intelligent control system, which controls motor speed accurately without the use of any conventional PI controllers and is independent of motor parameters. This study is conducted in both real time and simulation with a new control plant for a laboratory 3 ph, 3.8 Nm IPMSM digital signal processor (DSP)-based drive system. This DSP-based drive system is then compared with conventional BELBIC and an optimized conventional PI controller. Results show that the proposed method performs better than the other controllers and exhibits excellent control characteristics, such as fast response, simple implementation, and robustness with respect to disturbances and manufacturing imperfections.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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• pp.242-247
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• 2010

This paper introduces a real-time load flow program for Korean energy management system(EMS). This study is concentrated on the following aspects. First, we propose the model of the real-time database and power system equipment for the real-time load flow. These models are extracted from the needs of load flow functions and are designed to the application common information. Second, several techniques are applied for the efficient convergence and computational speed. The generation/load mismatch is redistributed using generator participation factors which are separated to the reference bus. For the voltage control, the jacobian matrix is composed with the basic Y matrix elements and the voltage control elements. Through the optimally ordering, jacobian row and column for a column is changed. However all jacobian matrix entries have same order with the Y matrix. The proposed program is tested using the Korea Electric Power Corporation(KEPCO) system. Through the test, we verified that the proposed program can be effectively used to accomplish the Korean EMS system.