A new type electrolyzing cell with slits on parallel plate electrodes and wire-to-cylinder type electrode system has been proposed instead of the conventional parallel plate type. An investigation was carried out on the effect of the number and size of slits on ion precipitation and oxidant generation characteristics, evidenced by eliminated space charge limiting action and by elevated electric fields in active interelectrode spacing. And it is also studied on the effect of the diameter of wire electrode to ion precipitation and oxidant generation characteristics. With electrode with 48 slits, very oxidants generation water of 3.1 [ppmm] and 19.0 [ppmm] in positive electrode side were obtained with tap water and 0.1 [wt%] NaCl dissolved tap waterfed. In addition, with wire-to-cylinder type electrode system, it is found that oxidant contained water of 0.48 [ppmm] and 5.46 [ppmm] in positive electrode side were obtained with tap water and 0.1 [wt%] NaCl dissolved tap water fed for the case of discharge electrode diameter of 0.5 [$mm{\phi}$]. Consequently, very high ion precipitation and dense oxidant generation characteristics can be realized by having slits on the electrodes of conventional cell as these slits increase the electric fields and decrease the space charge limiting actions in interelectrode spacing.

This paper developed a manufacturing method for resin magnet contained rare earth element and synthetic resin. Use this manufacturing method, developed a electro wave absorbent material and plant growth promote machine. Result of experiments shown to have excellent on bean sprouts cultivate, computer monitor, television monitor and cellular phone etc.

A Study on the electron energy distribution function in $SF_6+Ar$ mixtures gas used by MCS-BE algorithm, the electron swam parameters in the 0.5% and 0.2% $SF_6+Ar$ mixtures are measured by time of flight method over the E/N(Td) range from 30 to 300(Td). A two-term approximation of the Boltzmann equation analysis and Monte Carlo simulation have been also used to study electron transport coefficients. The electron energy distribution function has been analysed in $SF_6$ gas and $SF_6+Ar$ mixtures at E/N : 200(Td) for a case of the equilibrium region in the mean electron energy. The measured results and the calculated results have been compared each other.

Time dependent ozone generation characteristics of some oxide layers grown by ozone on the surface of corona discharge wires have been investigated experimentally in air ambience. Four wires of stainless steel, iron, silver and copper were used for the corona discharge wire of an ozone generator. And the effect of the metal oxide layers on ozone generation was studied and the contamination morphology of each layers was characterized. With the SEM images and the EDS spectra, it was found that all the surface of the corona wire were oxidized by the generated ozone and contaminated by airborne particles through the gradient force. As a result, the morphology and the electrical property of metal oxide layer grown on corona wire surface influenced on ozone generation characteristics i.e. discharge mechanisms.

A novel oxidant generation and ion precipitation cell with slits on parallel plate electrodes system has been proposed and an effect of the number and size of slits on ion precipitation and oxidant generation characteristics. As a result, with the electrodes with 48 slits($S=200{\times}60[mm^2]$. d = 1.5, 5.0 [mm]), it is found that the oxidant contained waters of 17.0 [ppmm] and 23.5 [ppmm] in acid water were obtained with 0.1 [wt%] NaCl dissolved tap water fed. And oxidant contained waters of 0.5 [ppmm] and 1.5 [ppmm] in alkali water were obtained with 0.1 [wt%] NaCl dissolved tap water fed. And the oxidant contained waters of 7.0 [ppmm] and 11.5 [ppmm] in mixed water were obtained with tap water and 0.1 [wt%] NaCl dissolved tap water fed. Consequently, very high ion precipitation and dense oxidant generation characteristics can be realized by having slits on the electrodes of conventional cells as these slits increase the electric fields and decrease the space charge limiting actions in interelectrode space.

Ozone has been widely applied to many industrial fields because of its strong oxidation effects. Therefore, the studies have been progressed for the effective and high concentration of one generation. The silent or surface discharge have been mainly used for high concentration ozone generation until now. But these two types of ozone generators have shortcomings to be improved. In this study, the ozone generator which improved the shortcomings of above two type of ozone generators was proposed and manufactured for high concentration ozone generation. And the proposed ozone generator could generate the surface and barrier discharge simultaneously. For this purpose, a mesh type discharge electrodes were proposed and the experiments were fulfilled as a function of the widths and spacings of mesh electrodes and gap spacings between the dielectric barrier and mesh electrode. When the width of mesh electrode[WM] and spacing of mesh electrode[SM] are 0.3[mm] and 0.8[mm] respectively, the maximum ozone concentration of 2.96[vol%] was obtained at 5.6[kV], 830[mA], gap spacing (S)=0.65[mm].

$ZnIn_2S_4$ and $ZnGaInS_4:Er^{3+}$ single crystals crystallized in the rhombohedral (hexagonal) space group $C_{3v}^5(R3m)$, with lattice constants $a=3.852{\AA},\;c=37.215{\AA}$ for $ZnIn_2S_4$, and $a=3.823{\AA}$, and $c=35.975{\AA}$ for $ZnIn_2S_4:Er^{3+}$. The optical absorption measured near the fundamental band edge showed that the optical energy band structure of there compounds had a direct and indirect band gap, the direct and indirect energy gaps are found to be 2.778 and 2.682 eV for $ZnIn_2S_4$, and 2.725 and 2.651eV for $ZnIn_2S_4:Er^{3+}$ at 293 K. The photoluminescence spectra of $ZnIn_2S_4:Er^{3+}$ measured in the wavelength ranges of $500nm{\sim}900nm$ at 10 K. Eight sharp emission peaks due to $Er^{3+}$ ion are observed in the regions of $549.5{\sim}550.0nm,\;661.3{\sim}676.5nm$, and $811.1{\sim}834.1nm$, and $1528.2{\sim}1556.0nm$ in $CdGaInS_4:Er^{3+}$ single crystal. These PL peaks were attributed to the radiative transitions between the split electron energy levels of the $Er^{3+}$ ions occupied at $C_{2v}$, symmetry of the $ZnIn_2S_4$ single crystals host lattice.

Our studies diagnose insulation degradation using the method of computer sensing system, which has the advantages of PD(partial discharge) and AE(acoustic emission) sensing system. To use advantages of these two methods can be used effectively to search for treeing location and PD in some materials. In analysis method of degradation, using statically operator such as the center of gravity (G), the gradient of the discharge distribution(C), we have analyzed for the prediction of life which we can be obtained the time, occurred of many pulse of small discharge amplitude.

In the recognition of the gases using the quartz crystal microbalance (QCM) coated with the film materials, it is important to obtain the recognition ability of gases, and the stability of film coated above the QCM. Especially, the thickness of film coated above the QCM is decreased according with the using circumstance and time of QCM gas sensor. Therefore, the sensing characteristics of film is changed with these. In this paper, we coated the lipid PC (Phosphatidyl Choline) materials varing with the blended amount of PVC(Poly Vinyl Chloride) and solution (Tetra Hydrofan:THF) above QCM to obtain the sensitive and the stability of lipid PC film. QCM gas sensors coated with film materials were measured the frequency change in the chamber of stationary gas sensing system injected 1-hexane, ethyl acetate, ethanol and benzene of $20{\mu}{\ell}$, respectively. We also measured the degradation characteristics of QCM gas sensor to show the properties of stability.

The purpose of this study is to find the way to reduce the electrostatics by interface activation substances added in the insulating oil with concentration[ppm]. As results, The streaming current, surface tension and viscosity of the samples added nonionic and hermaphrodic substances are decreased but the conductivity is increased at higher point than the 1[ppm](c.m.c.), the other side the same phenomena of the samples added cationic and anionic substances are discovered at the 10[ppm].

In this paper, the coupled and the non-coupled vibration mode AE sensor for GIS were simulated by finite element analysis and manufactured, and characterized. The maximum sensitivity was 64.3 dB when the resonant frequency of the coupled vibration mode AE sensor was 166 kHz and the maximum sensitivity was 58.9 dB when the resonant frequency of the non-coupled mode AE sensor was 265 kHz. The coupled vibration mode AE sensor responded higher than the non-coupled vibration mode AE sensor at the partial discharge detection in GIS.

$CdGaInS_4$ and $CdGaInS_4:Er^{3+}$ single crystals crystallized in the rhombohedral(hexagonal) structure. with lattice constants $a=3.913{\AA},\;c=37.245{\AA}$ for $CdGaInS_4$, and $a=3.899{\AA}$ and $c=36.970{\AA}$ for $CdGaInS_4:Er^{3+}$. The optical absorption measured near the fundamental band edge showed that the optical energy band structure of these compounds had a direct and indirect band gap. the direct and indirect energy gaps are found to be 2.771 and 2.503 eV for $CdGaInS_4$, and 2.665 and 2.479 eV for $CdGaInS_4:Er^{3+}$ at 10 K. The temperature dependence of the optical energy gap was well represented by the Varshni equation. In $CdGaInS_4$, the values of ${\alpha},\;{\beta}$ of the direct and the indirect energy gap were found to be $7.57{\times}10^{-4}eV/K$. $6.53{\times}10^{-4}eV/K$ and 240K. 197K. and the values of ${\alpha}$ and ${\beta}$ of the direct and the indirect energy gap in the $CdGaInS_4:Er^{3+}$ were given by $8.28{\times}10^{-4}eV/K,\;2.08{\times}10^{-4}eV/K$ and 425 K, 283 K, respectively.

본 논문은 영구 자석 동기 모터의 속도 제어를 위하여 슬라이딩 모드 제어 기법을 도입하였다. 또한 기계적인 위치 또는 속도 센서 없이 속도 제어를 수행하기 위하여 부하 토크 및 속도 관측기를 이용하였으며, 시뮬레이션을 통하여 그 성능을 확인하였다.

This paper deal with a design and a constant output power control of Zero Current Zero Voltage Switching(ZCZVS) resonant type DC-DC converter by a digital I-PD phase shift controller. When the DC-DC converter for a high density and a high effect control is operated in high speed switching, the switching loss and switching stress of the switching devices are increased. So, the ZCZVS method, which has the phase shift control with the digital I-PD controller, must be use in order to reduce its. And the constant output power voltage that controlled by the digital I-PD controller tracks a reference without steady state error in variable input voltage. The validity of control strategy that proposed is verified experimental results by the Digital Signal Processor TMS320C32.

최근 고 에너지 저장 및 발생장치의 개발은 군사용에서 산업용으로 응용되면서 각종 첨단 설비가 개발되고 있다. 본 논문에서는 전자빔 발생기로 쓰이는 Gyroklystron용 대전력, 고전압, 전류 펄스 전원장치로 입력부, 특고압 발생부, 고압 정류부 및 IGBT 펄스 스위치 구성하고 그 설계 및 개발 자료에 대하여 기술하였다. 대전력 고전압 전류펄스 전원장치를 위한 각 구성 부분의 제어 및 설계 특징은 다음과 같다. 입력부인 IGBT Inverter는 펄스 전원장치의 제어를 위하여 출력 고전압을 Feedbark System에 의해 펄스 설정 전압을 유지하도록 제어하며, 또한 펄스 출력중에 직류 고전압부의 전압강하, 즉 펄스 진압의 Drop이 커지는 것을 방지하기 위하여 Fast Dynamics를 갖도록 Feedback System을 구성하였다. 단상 특고압 승압용 변압기 3대를 직렬접속한 특고압 발생부는 PWM 제어된 전압을 입력받아 특고압으로 승압시키며 고압 펄스성 전압과 매우 높은 dV/dt 전압이 인가되므로 Stray Capacitance가 최소가 되어야 하며 절연파괴로부터 보호될 수 있어야 한다. 고압 정류부는 Inverter와 특고압 변압기에 의하여 전원이 공급되므로 교류전압의 교번 순간에 매우 높은 전압변동률을 가지는 Fast Recovery High Voltage Rectifier로 설계 제작되어졌다. 펄스 스위치인 IGBT 스위치는 Gate Driver에 의해 구동되어 지며 주어진 펄스 사양을 만족시키게 된다. 특히 소자의 전압특성을 고려하여 120KV의 전압 값을 갖도록 설계, 제작하였다.

In this paper a switching control circuit for shaping the line current and reducing the total harmonics distortion in the boost converter is presented. To solve the problems of performance degradation due to pulse waveform in the input current, the boost converter in which the harmonic distortion in the input current is reduced using a 3th harmonic-injected PWM is proposed. Finally, Simulation and experimental results of boost converter with 5[kHz] switching frequency are presented and correction of power factor and reduction of total harmonic distortion was established.

This paper presents an implementation of digital position control system for an induction motor vector drives by a direct torque control(DTC) using the 16bit DSP TMS320 F240. The DSP controller enable enhanced real time algorithm and cost-effective design of intelligent controller for motors which can be yield enhanced operation, fewer system components, lower system cost, increased efficiency and high performance. The system presented are stator flux and torque observer using current model that inputs are current sensing of motor terminal and rotor angle for a low speed operating area, two hysteresis controller, optimal switching look-up table, and IGBT voltage source inverter by fully integrated control software. The developed control system are shown a good motion control response characteristic results and high performance features using 2.2Kw general purposed induction motor.

This paper was development a discharge lamp ballast in order to wave improvement of high power factor and high efficiency. The discharge lamp ballast consists of a power factor correction circuit and a correction circuit on switching frequency of inverter. Instead of passive power factor circuit, active power factor circuit is adopted. Because it has the advantage of size, weight, total harmonic distortion, out DC voltage regulation, and power factor. The power factor circuit with MG34262 is controlled by variable frequency discontinuous mode. Results experiments, discharge lamp ballast is showed to have excellent for the proposed electronic ballast's operation and characteristics.

This paper is focussed on an optimal efficiency control which is operated by voltage-current pattern such as to maintain the maximum efficiency output characteristics of the motor. The voltage control is realized by phase control thyristers.

This paper presents a technique for contingency ranking using line capacity calculation method and outage distribution factors (LODF) which are established by generation shift distribution factors from DC load flow solutions. By using the LODF, the line flow can be calculated a ccording to the modification of base load flow if the contingency occur. To obtain contingency ranking, maximum power tansferred to the load is obtained when load impedance $Z_r$ equal to line impedance $Z_s$. The proposed algorithm has been validated in tests on a 6-bus test system.

The finite element method (FEM) is suitable for the analysis of a complicated region that includes nonlinear materials, whereas the boundary element method (BEM) is naturally effective for analyzing a very large region with linear characteristics. Therefore, considering the advantages in both methods, a novel algorithm for the alternate application of the FEM and BEM to magnetic field problems with the open boundary is presented. This approach avoids the disadvantages of the typical numerical methods with the open boundary problem such as a great number of unknown values for the FEM and non-symmetric matrix for the Hybrid FE-BE method. The solution of the overall problems is obtained by iterative calculations accompanied with the new acceleration method.

This paper presents an algorithm for optimal reactive power dispatch problem based on Improved Genetic Algorithm(IGA). Optimal Reactive Power Dispatch (ORPD) is particularized to the minimization of transmission line losses by suitable selection of generator reactive power outputs and transformer tap setting. For the objective, in this paper, Loss Re-Distribution Algorithm(LRDA) is new applied to the equality constraint of ORPD. The proposed method has been evaluated on the IEEE 30 bus system. Results of the application of the method are compared with a base case.

The electric charge generated by flowing insulation liquid can create hazardous spark in transfer line and receiving tank etc. These electrification has generally been measured by current measurement with a ammeter connected to the receiving tank. This paper reports on the experimental result obtained by this method. As a experimental results: The injected charge value for unit volume increased in the following condition, the edge of the needle electrode was sharp, the number of needle electrode was fewer, the edge of the needle electrode was located close to the inside wall. When the charge density in the charge reducer is constant, electrode current and electrode potential by the charge injection from outside increase with increasing of oil velocity and streaming current. The electrode potential in charge reducer is made maximum value at edge point of reducer inside and minimum value at center line of charge reducer.

본 논문에서는 진화연산 중에서 해의 다양성과 수렴속도면에서 좋은 성능을 나타내는 실수형 유전알고리즘과 신경회로망을 이용한 적응 퍼지제어기를 설계하였다. 실수형 유전알고리즘을 이용하여 퍼지제어기의 입 출력 이득과 실시간으로 퍼지제어기의 입 출력이득을 적응적으로 변경하는 신경회로망의 가중치를 튜닝하였다. 제안한 방법의 유용성을 평가하기 위해 시지연을 갖는 제어시스템[14]에 적용하였다. 컴퓨터 시뮬레이션 결과, 제안한 적응 퍼지제어기가 기존의 퍼지제어기보다 오버슈트, 정정시간, 상승시간면에서 더 우수한 제어성능을 나타내었다.

The SRM is a simple and robust machine which is finding applications over a wide power and speed range. To properly evaluate the motor performance, a reliable model design is required. This paper explains the various excitation mode and winding configuration to analyze the torque performance of SRM. A number of different idealized current excitation patterns are introduced, using unipolar, bipolar & square excitation, and the output torques produced by the various winding configurations are compared. The electromagnetic torque of the SRM was calculated from the rate of change of co-energy with respect to angular displacement. The simulation result shows that 3-phase square excitation mode models have revealed higher torque performance.

The moving vehicle with disturbances has the 6 degree of freedom motion in the pitching, Yawing, and rolling directions of two independent axes. The control system in such a moving vehicle has to perform disturbance rejection. This paper present PID controller with disturbance rejection function, low sensitivity filter and notch filter for bending frequency rejection. The performance of a designed system has been certified by the simulation and experiment and experiment results.

본 논문에서는 ADSL 모뎀용 아날로그 Front-end 단에 사용되는 Rx과 Tx단의 연속시간 Gm-C 고역 및 저역 통과 필터를 설계하였다. 설계된 Tx의 아날로그 저역 통과 필터는 차단 주파수, 138kHz의 3차 Elliptic 함수를 이용하였고, Rx에서는 138kHz의 3차 Butterworth 고역 필터와 1.1MHz의 3차 Butterworth 저역 필터를 이용하여 설계하였다. 설계된 모든 필터는 주파수와 이득의 튜닝을 용이하게 하고 잡음특성에 유리한 연속시간 Gm-C 실현 법을 이용하여 구현하였다. Gm-C 실현 법을 이용하기 위하여 선형 특성이 개선된 Gm-C 적분기를 새롭게 설계하여 이용하였다. 설계에 활용된 파라미터는 IDEC에서 제공한 아남의 $0.25{\mu}m$ CMOS 1-poly, 5-metal 공정 파라미터를 이용하였으며, 2.5V의 저전압으로써 회로로 구성하였고 HSPICE를 이용하여 검증하였다.

This paper proposes the novel control of a static synchronous compensator (STATCOM). This STATCOM system consists of cascade multilevel inverter which employs H-bridge inverter(HBI) The STATCOM system is modeled in the d-q transform matrix. This model is used to design a controller. The selective harmonic elimination method(SHEM) allows to keep the total harmonic distortion (THD) low in the output voltage. The switching method produces the staircase type waveform in cascade multilevel inverter. To balance the DC voltages in HBIs capacitor, the rotated switching scheme is newly proposed in this paper. The proposed control scheme is verified in the simulated results.

In this paper, we are applied the Genetic Algorithm(GA) to design of the robust $H^{\infty}$ speed controller by auto-tuning of the weighting function. GA is used to design of the weighting functions in the robust $H^{\infty}$ controller. To evaluate the performances of the proposed robust $H^{\infty}$ controller, we make an experiment on $H^{\infty}$ speed controller of an actual DC servo- motor system with nonlinear characteristics. Experimental results show that proposed controller have better performance than those of PD controller.

본 논문에서는 완전균형 상보형 적분기에서 그 이득과 단위이득 주파수 특성을 향상시킬 수 있는 high-swing cascode 구조를 이용한 새로운 적분기를 설계하였다. 설계된 high-swing cascode 적분기는 $0.25{\mu}m$ n-well CMOS 공정 파라미터를 이용하여 HSPICE 시뮬레이션 하였으면, 그 결과 제안된 회로는 2V 공급전압에서 전력소모는 1.04mW이고 차단주파수는 100MHz를 갖으며 이득은 51dB로서 이 적분기를 이용한 능동필터 설계시 요구조건인 40dB 이상의 이득 값을 만족한다.

A Switched Reluctance Motor(SRM) has been widely studied for practical use due to recent development on technology of power electronics. Because of its advantage that are high speed driving, simple structure and easy variable-speed control, it is expected for applications to automo biles and others. However, it has some problems that are, for examples, relatively high torque ripples and electromagnetic noise. In this paper, a simple theory is presented to represent characteristic of a SRM and theoretical results are compared with experimental ones. In the theory, the inductance variations of a SRM are approximated as linear and winding resistances and the magnetic saturation are ignored. With these approximations, we derived some equations expressing load characteristics of a SRM. Also, the torque ripple was removed by applying a variable hysteresis band control.

The electronic ballasts for low pressure discharge lamps are produced and commercialized. However, the electronic ballasts for high pressure lamps are now in progress because of poor reliability and high cost. The major case of troubles with electronic ballasts are thermal destruction of semiconductor output switches due to non ideal i-v characteristics of switch. The loss converts to heat and rises the temperature of switch and it increases proportionally to switching frequency and value of current and voltage. This study shows the variable frequency ballasts which can suppress the heating of switches efficiently. It is used for the limitation the switch current and the rising temperature of switch by impedance variation of lamp inductor. As a result, initial warm-up time of the proposed ballasts was faster than that of magnetic ballasts about 90 msec. Power factor of tested ballasts follow as ; input and output average of magnetic ballasts are 93 [%] and 86 [%], respectively, And proposed ballasts are 97 [%] and 99 [%], respectively.

In this paper, a maximum efficiency control technique of real-time processing in which parameter variation is compensated in vector control of an induction motors(I.M.) is proposed. Based on equivalent model of I.M., a loss minimization factor(LMF) with the variations of speed is derived. To solve problem of inaccuracy of LMF curves due to machine parameter variation, rotor resistance estimation is performed by using instantaneous reactive power. The estimated rotor resistance values are applied to the maximum efficiency control with a LMF.

동일 스위칭 주파수하에서 PWM 인버터의 출력 파형에 발생하는 고조파성분을 억제하기 위해서는 3 레벨 PWM 전력회로가 우수하다. 따라서 본 연구에서는 단상 PWM 인버터의 전력회로를 기존의 풀브릿지 방식과 하프 브릿지 방식의 전력회로를 적절히 변형함으로써 출력전압이 3 레벨로 나타나는 전력회로를 제안하였다. 또한 전동기 기동시와 같은 순시적으로 정격전류 이상의 전류를 요구할 시 제어모드의 변화로 일정전류모드로 출력전압을 제어하고, 정격전류 이하의 전류에서는 부하번동에 따른 편자현상을 보상하기 위해 Deadbeat전류제어기를 구성하였다.