• Journal of Electrical Engineering and Technology
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• 제3권4호
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• pp.559-565
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• 2008

This study designed a new type of loop antenna that is able to detect partial discharges based on microstrip line technology. In the diagnosis of power cables, partial discharge signals are generally produced at a frequency range less than 100MHz because high frequency PD signals are lost along a propagation path in such cables. The new type of loop antenna sensor has been studied using simulation software known as CST microwave studio version 5.0. In partial discharge measurement experiments, a commercial HFCT sensor was used as a reference sensor. Several experiments were made over HFCT and loop antenna sensors for detecting partial discharges on 22.9kV MV XLPE cable. In this study, we showed the loop antenna designed in this study that can be applied as a commercial HFCT sensor.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.210-211
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• 2007

The objective of this paper is to effectively detect partial discharges in underground power cables. In this field, we have been usually applied several sensors for such partial discharges. This study used a type of beyond compare antenna based on the influence of background noises. Also, we designed a new structure that is able to easily apply in the adhesion of planar loop types for underground power cables in measurement sensitiveness elevation. A high frequency simulation tool (CST-MWS) was applied to the antenna used in this study, and it was used to evaluate certain characteristics. We fabricated an antenna using the simulation data obtained from a specific test. After checking the sensitivity of this Planar Loop Sensor in the Lab, it was tested in an actual site. This paper analyzed the data as a part of time and frequency domain using an oscilloscope and spectrum analyzer, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 춘계학술대회 논문집 센서 박막재료연구회 및 광주 전남지부
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• pp.27-31
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• 2008

In this study, The new type of loop antenna which detects the partial discharge was designed based on microstrip line technology. In diagnosis of power cable, partial discharge signal generally occurred at the frequency range lower than 100MHz because high frequency PD signals could be lost along the propagation path in the cable. The new type of loop antenna sensor has been studied by using Simulation software named CST microwave studio version 5.0. In partial discharge measuring experiments, commercial HFCT sensor was used as a reference sensor. Several experiments were made over HFCT sensor and loop antenna sensor in detection partial discharge on MV XLPE cable of 22.9kV. In this study, we have shown our loop antenna sensor can apply as a commercial HFCT sensor.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.156.5-156
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• 2001

Stabilized tracking platform in a missile consisting of a flat planar antenna, pitch/yaw gimbals, gear trains, and current controlled DC drive motors for pitch and yaw gimbal must have a capability to track a target as an inertial sensor in the presence of missile body motion such as maneuvering and vibration. Because of this reason, tracking a target from dynamic platform requires a servo architecture that includes a outer tracking loop(position loop) and inner rate loop that stabilizes the line of sight(LOS). This paper presents a gimbaled platform model including nonlinear phenomena due to viscous and Coulomb friction based on experimental data and torque equilibrium equation, the design concept for the inner tacholoop having P controller structure ...

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.552-558
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• 1993

In this paper, control of a planar two-link structurally flexible robotic manipulator executing unconstrained and constrained maneuvers is considered. The dynamic model, which is obtained by using the extended Hamilton's principle and the Galerkin criterion, includes the impact force generated during the transition from unconstrained to constrained segment of the robotic task. A method is presented to obtain the linearized equations of motion in Cartesian space for use in designing the control system. The linear quadratic Gaussian with loop transfer recovery (LQG/LTR) design methodology is exploited to design a robust feedback control system that can handle modeling errors and sensor noise, and operate on Cartesian space trajectory errors. The LQG/LTR compensator together with a feedforward loop is used to control the flexible manipulator. Simulated results are presented for a numerical example.

• 센서학회지
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• 제25권1호
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• pp.8-12
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• 2016

A planar, light-weight, and low-cost notch filter structure is required for the KSTAR ECEI (Electron Cyclotron Emission Imaging) system to protect the mixer arrays from spurious plasma heating power. Without protection, this heating power can significantly degrade or damage the performance of the mixer array. To protect mixer arrays, a frequency selective surface (FSS) structure is the suitable choice as a notch filter to reject the spurious heating power. The FSS notch filter should be located between the lenses of the ECEI system. This paper presents a 170 GHz FSS notch filter for the KSTAR ECEI sensor application. The design of such an FSS notch filter is based on the single-sided square loop geometry, because that makes it relatively insensitive to the incident angle of incoming wave. The FSS notch filter exhibits high notch rejection with low pass-band insertion loss over a wide range of incident angles. This paper also reviews the simulated and measured results. The proposed FSS notch filter might be implemented in other millimeter-wave plasma devices.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1992년도 춘계학술대회 논문집
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• pp.369-373
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• 1992

Force control of a planar two-link structurally flexible robotic manipulator is considered in this study. The dynamic model is obtained by using the extended Hamilton's principle and the Galerkin criterion. A method is pressented toobtain the linearized equations of motion in Cartesian space for use in designing the control system. The approachto solving the control problem is to use feedforward and feedback control torques. The feedforward torques maneuver the flexible manipulatro along a nominal trajectory and the feedback torques minimize any deviations from the nominal trajectory. The linear quadratic Gaussian/loop transfer recovery (LQG/LTR) design methodology is explotied to design a robust feedback control system that can handle modeling errors and sensor noise, and operates on Cartesian space trajectory errors. The Lqg/LTR compenstaor together with a feedforward ollp is used to control the flexible manipulator. Simulated results are presented for a numerical example.

• 조명전기설비학회논문지
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• 제12권3호
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• pp.14-21
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• 1998

본 논문에서는 평판형 전장센서와 멀티턴 루우프형 자장센서를 이용하여 2회선 345[kV] 송전선로에서 발생하 는 극저주파 영역(ELF)의 전장과 자장의 값을 측정하고, 이들의 크기를 3차원 그립으로 나타내었다. 또한, 자장 은 부하전류에 비례하므로 부하변동에 따른 자장의 값올 예측할 수 있도록 그 송전선로의 대표적인 일부하 전류 곡선을 나타내었다 선로 중심점으로부터 횡방향 거리에 대한 측정값을 FIELDS 프로그램에 의해 계산된 이론 값과 비교하였다. 전장의 세기는 송전 철탑 내부와 주변에서 낮게 나타났고, 자장의 경우 최대값이 나타난 지점 은 중부하 회선쪽으로 이동하였으나, 대체로 철탑의 중심부분에서 최대치가 나타나는 경향을 보였다. 송전철탑 주변에서 최대 전장과 자장의 값은 각각 3.5[kV/m]와 $20[{\mu}T]$ 를 초과하지 않았으며, 본 연구에서 측정된 전장과 자장의 값은 관련 여러 국제기관에서 제시한 제한.권고치를 만족시키고 있다.