본 논문은 고압 나트륨 램프용 전자식 안정기의 회로 특성을 보다 효율적이고 경제적으로 비교 평가하기 위해, Pspice를 이용하여 전자식 안정기 구동회로를 시뮬레이션하고 이를 실제 안정기 출력과 비교한 논문이다. 본 논문에서 사용한 방식은 공진형 인버터를 이용한 Half-Bridge Inverter 구조의 자려식 구동방식으로서 실제 안정기의 동작 특성과 같은 시뮬레이션 결과를 얻을 수 있었다.

This paper describes a design of the external-exciting electronic ballast for 100W high pressure sodium lamp. The ballast is consists of the full-bridge inverter and an external-exciting control circuit. L and C values of an equivalent L-C series resonant circuit are calculated analytically. The electrical output characteristics of the ballast, such as voltage, current etc., are simulated by Pspice. The experimental results from high pressure sodium lamp system with the ballast we developed are shown to be consistent with the simulated results.

본 논문은 인가된 전원 주파수와 파형이 형광램프의 광효율에 미치는 영향에 대해 다루고 있다. 실험결과를 살펴보면 각 파형별 전원전압의 주파수 변화에 따라 광효율은 완만한 증가를 하고 있음을 알 수 있으며, 25[kHz]에서의 각 파형별 인가전압에 따른 램프전압에 대한 FFT분석에 있어 파형에 따른 spectrum power 변화는 크지 않았으며, peak spectrum은 주파수 15[kHz] 부근임을 확인하였고, 차후로 좀 더 넓은 주파수 대역에서의 실험이 행해져야 할 것이다.

Nowadays, natural resource are running out and the level of the environment contamination is getting serious. To solve these problems, each country and institute tend to need many-sided researchs and developments. At this point, especially, there are many coal-mines in Jung-sun and Tae-back where are located in Kangwon province. By the way the abandoned mines cause not only local economy collapse but also environment contamination by submergence of stony mountains. The counterplan is positively inquired further examination by the government. Consequently, we hope that the recycle of polymer concrete can reduce the environment contamination, suggest the new direction of Green Design and can be switched over high added value goods. In conclusion, the recycle of polymer concrete will be valuable.

This study minimized the address pulse width for plasma display by analysis of address discharge condition for high speed driving using the ADS driving scheme. As a result, addressing pulse width of 1$mutextrm{s}$ has been realized and luminance of 560cd/$m^2$ can be obtained from the area of 256X160 pixels. And a new AWD scheme is proposed. We accomplished 9.1-inch-diagonal color image with the scan timing of HDTV class PDP, display duty 96.8%.

기구 배광이 전체적인 조명환경에 미치는 영향은 크며, 기구배광은 반사판, 프리즘 설계 등으로 구현된다. 또, 램프의 물리적 크기는 기구설계에서 무시할 수 없으며, 기구 설계자는 램프로 흡수되는 빛을 최소한으로 하여 기구를 설계하여야 한다. 기존의 반사판 설계 알고리즘의 경우 램프의 물리적인 크기를 고려하지 않았으며, 기구배광의 출력값도 몇몇의 경우에서는 오차를 발생하였다. 이에 본 논문에서는 램프의 키기를 고려한 반사판설계 알고리즘을 개발, 구현하여 이전의 기구설계 알고리즘이 가지고 있던 오차를 줄였으며 좋은 성과를 얻었다.

조명시스템의 경제성에 크게 영향을 주는 요소들을 보면 초기 설비비, 보수비, 전기요금 등이 있다. 이 중에서 보수비는 램프 교환비, 램프교환 인건비, 청소비로 구성되어 있으므로 보수계획에 따라서 조명시스템의 경제성이 다르게 나타난다. 따라서 설계초기에 어떠한 조명시스템이 경제적으로 유리한가를 예측하는 것은 중요하다. 그러므로 본 연구에서는 국내에서 평균조도를 계산하는데 사용되는 ZCM에서의 보수율 구성 요소들을 변화시켜 보수율 값을 산정한 후 조명시스템의 경제성 평가 위해 개발한 WEELS(Worksheet for Economics Evaluation of Lighting Systems)에 적용하여 조명시스템에서 보수율의 중요성을 보였다.

This report compares illuminance of formula with the one of the Lightscape which is lighting simulation system, and applied IES file to the Lightscape by angles and coordinate. As a result of correct solution in comparison, we got a satisfactory result from this study. We effectively hope to make the road lighting calculations through the collection and preparation for the lighting data in detail.

This paper gives various load profiles of power transformers and motors in apartment housing. The load profile of power transformer shows that it is peaked in winter by heating system, and the maximum value of load profiles in power transformer is ranged 25%∼35%, which shows it is operated on over-capacity. The maximum value of demand factor in water supply system is about 60% and this of wastewater treatment system is about 50%.

In this paper, 7-segment was implemented using AC powder EL. ZnS:Cu and BaTiO3 was used as a phosphor and dielectric respectively. The preparation of phosphor and dielectric layer was performed with screen printing. The implemented system of 7-segment was divided as following; EL display, driving circuit, software for driving. The properties of fabricated devices was measured with EL spectrum and brightness.

In the charge system, a contact type-convenient-charging method is insufficient because of the contact failure around moist environment and troublesome question to put in and pull out. For the solution of this problem, an electromagnetically coupled non-contact charger for the rechargeable cell is proposed using ZVS multi-resonant forward converter with synchronous rectifier. In this paper coupling coefficient(k), leaking inductance, coupling inductance and resonant frequency are observed for the air gap. By using the observed value, this circuit is designed and implemented. This proposed circuit is simulated by the PSPICE and experimented. The stress of a main switch and the output power are measured.

The purpose of this paper is to describe a new measuring method of ground resistance for the grounding system in energized power equipment and substations. It is very difficult to measure the accurate ground resistance in energized power equipment and substations because of the noise conducted from all external connections to the grounding system and harmonics components caused by unbalanced loads and overloads. The ground resistance that is measured with existing methods includes not only the effect of desired signals but also noise components for the measurement period in grounding system. The measured value of ground resistance can entirely be different from actual value. In this paper, to eliminate 60[Hz] power system interference and harmonic components the low-pass filter method was used in the measurement of ground resistance.

The paper considers the theoretical problem of eliminating harmonics in inverter waveforms. The problems associated with the harmonics distortion of PWM inverter devices were analysed. Voltage control methods are variable parameter each harmonics magnitude improve the voltage wareform.

Recently many research activities on the diagnosis of stator winding insulation of large rotating machines have been reported. Capacitive couplers are widely used as sensors for on-line partial discharge (PD) measurement of high voltage rotating machines. This paper presents laboratory test to compare Stator Slot Coupler (SSC), Resistance Temperature Detector (RTD), 80 [pF] coupler and 500 [pF] coupler for on-line PD measurement of rotating machines. And a novel on-line monitoring system for an insulation diagnosis is proposed.

This paper describes an application of the partial discharge measuring method in operating transformer. In the operating transformer, the useful PD signal may be superimposed by radio intereference voltage and impulse shaped noise signals generated by external corona or power electronics. In this paper, initial investigations after connecting the PD measuring system to the terminals of the measuring impedance showed a very high noise level of 3,700pC due to sinusoidal interferences. In order to reject these noises, this paper applied RIV and band-pass filters and noise gating method. The resulting measuring sensitivity was improved from 3,700pC to 160pC.

This paper present the design, produce, circuit design and practical measurement for a Brushless DC Motor(BLDCM) with Ferrit-Magnet. It was used PI controller. The practical PI control has bin widely used for DC-Motor.

This paper deals with the design of the electronic ballast for high pressure sodium lamp, which consists of the ignitor and the resonant converter for driving the lamp. Also it contains PFC(Power Factor Controller) to improve such as power factor, low distortion etc. In this paper, we design the electronic ballast for the 150 watt high pressure sodium lamp.

In this paper, a prototype electronic ballast for 400W MH lamps is designed and implemented. To remove the phenomenon of acoustic resonance in the lamp being operated at high frequency, a spread spectrum method is employed on the ballast. Half-bridge resonant inverter, voltage-controlled-oscillator and PFC are used and the current of lamp is controlled with taking into account the voltage of lamp. The ballast is built with analog OP-amps and MOSFETs. The experimental results show the good performance as PF 0.93, ATHD 0.14, Ballast loss 22W at output 400W.

설계초기단계에서 고효율 조명기기의 채택을 원활하게 해주고, 동시에 LLF값을 산정 해줌으로써 건물설계에 적용되는 조명에너지를 절감해주기 위해서는 조명 설계 기법의 고도화와 조명 설계 과정의 표준화가 필요하다. 이를 위해서 구역공간법(ZCM: Zonal Cavity Method)을 이용한 평균조도 계산용 소프트웨어를 개발하였다.

공간의 효율적 조명시스템의 설계를 위해서는 그 공간의 물리적 조건들과 작업의 내용 등을 고려하여 표준적인 상황을 규정하고, 그 상황에서 가장 유용한 조명설계를 찾아내어 표준화해야 한다. 특히, 인텔리전트 빌딩에서는 OA도입으로 인한 VDT 작업환경, 취업인구의 고령화 등의 공간특성을 고려한 조명계획이 요구되며 이러한 조명계획을 구현할 수 있는 조명기구를 제작할 필요가 있다. 따라서 이 연구에서는 국내 인텔리전트 빌딩의 주요공간별 크기와 형태 및 특성을 조사하여 표준공간을 선정했고, 이를 반사판 설계에 반영하여 3가지 형태의 형광등기구를 설계, 분석하였다.

우리 나라의 터널 조명은 운전자의 시야상태를 저해하는 불균일한 조도 균제도, 터널 내의 플리커 현상, 심한 눈부심 등과 함께 낮은 기구효율, 낮은 조명률, 높은 에너지 소비 등의 문제점을 갖고 있다. 이러한 것들을 개선하기 위해서 터널용 고효율 조명기구의 반사판을 개발하였고, 개발된 조명기구는 기구 자체 효율이 10%이상 상승함으로써 에너지의 절감과 조명효과의 상승을 가져왔으며, 기구 대수의 저감으로 건축비를 축소시켰다. 또한 이것을 이용한 터널조명에서는 평균조도 200[lx]이상, 전반 균제도 0.4이상, 차선축 균제도 0.7이상, 단위 면적당 소비전력 3.7 [W/$m^2$]이하의 효과를 얻었다.

This parer is the among educational environment, lighting's role is more important since it improves the visual tasks, capability of work, and it help to build both balanced mind and body. Also, since students need spend most of their time inside rather than outside, students need appropriate illuminance everyday. If optimum illuminance and distribution of luminance is properties controlled, people can decrease the fatigue of eyes, and also, people can maximize their efficiency of work. This present studying class chose of two school measured illuminance using the computer simulation improved ratio of luminance and luminance by distribution of lighting improve the economy and energy saving.

We presented a modified triangular interferometer as an incoherent holography, which can eliminate bias and conjugate image problems of the conventional one. Also, to demonstrate the feasibility of incoherent holography, the formation of an incoherent hologram using a mercury lamp and its optical reconstruction were presented.

This paper is on the edgelit device with external control function and change of light color by dimming control of high flux LED. It the light is projected the transparent body via reflector, the mixture of light is uniform and it is proved by simulation and experimentation. To improve the light efficiency of the device, the research on reflector materials and the distortion of LED input owing to the transistor's characteristics are need.

This paper describes the self healing characteristics of metalized polypropylene film(MPPF) under ac condition. PDs were generally observed at relatively low voltage, and the PDIVs were differently varied depending on the number of pre-self healing due to void defects. Several pre-self healing events took place at lower voltage than the critical breakdown voltage of PPF. Self healing mainly occurred at pin tips, wrinkle sides, and cross points of wrinkles. The applied voltage at self healing was increased with PPF thickness. The burn out area at self healing was also increased with the applied voltage and PPF thickness. The peak currents in a grounding conductor at self healing was also increased with the applied voltage.

This paper describes the study on the basic characteristics of discharge generated in cable splices using ultrasonic measurement method. Two kinds of defect which might be existed in a real cable splice were simulated. One is surface discharge moisture and metallic alien substances and the other is partial discharge by metallic particle. As a result, there were some differences in the characteristics of ultrasonic signals according to each defect. Therefore, it was found that is could be possible to protect the failure in cable splices in advance by analyzing the ultrasonic signals coming from the cable splice due to partial discharge.

This paper proposes the new concept & design method and implementation of LonWorks network system for remote monitoring & lighting dimming control and telemetry using Web network. The Experimental LonWorks network system for telemetry & remote monitoring and control are designed and fabricated. As a result, it is verified that LonWorks is open, interoperable, reliable network system from the experimental results, especially, it seamlessly links the data and control networks, allowing the IP(internet) network to be treated as an extension of the LonWorks networks, and vice versa.

This paper describes a Push-Pull type high frequency resonant inverter composed of consolidation of boost converter circuit and resonant inverter circuit. By using a boost converter circuit, the proposed inverter can obtain a twice input voltage of resonant circuit and reduce a secondary turn ratios. also, by using both switching device of boost-converter and resonant circuit, the number of switching device can be reduced by half, the analysis of the proposed circuit was generally described by using normalized parameter and operating characteristics have been evaluated as to switching frequency and parameters. In the future, this proposed inverter shows that is can be practically used as a power source system for the lighting equipment of discharge lamp, induction heating applications.

The time sharing type high frequency inverter using serial-parallel resonant to give VVVF function in the inverter used as power source of induction heating at high frequency is presented in this paper. This proposed inverter can reduce distribution of the switching current because of using the current of serial resonant circuit to the input current of the parallel one. The analysis of the proposed circuit is generally described by using the normalized parameters. Also, according to the calculated characteristics value, a method of the circuit design and operating characteristics of the inverter is proposed. In addition, this paper proves the validity of theoretical analysis through Simulation. This proposed inverter show that it can be practically used in future as power source system for induction heating application, DC-DC converter etc.

This paper investigates characteristics of spiral charge for charge simulation method to calculate electric fields of spiral conductor bundles with spiral rods in 765 kV transmission line. We finds the simulating spiral charge as constant charge density give less potential calculation error than sinusoidal charge density. When a spiral rod is simulated as spiral charge, we also knows two spiral charge can simulate spiral rod best.

This paper deals with multiresolution analysis of wavelet transform for partial discharge(PD), both corona and surface discharge. Multiresolution analysis was used for performing discrete wavelet transform. PD signals was decomposed into "approximation" and "detail" components until 4 levels by using discrete wavelet analysis. In this paper, daubechies family is adopted for the research of the characteristics of PD signals. The results show that in corona discharge the segment 7, 8, 9, 10, 11 values of defined variable is increased with discharge process, so phase distribution is characterized by 210~330 ranges. In case surface discharge in expoxy insulator inserted, defined variable values is fairly symmetric discharge pattern because coupled both corona and dielectric bounded discharges. We can confirmly discriminate the type PD source. the type PD source.

This paper presents a novel prototype of soft-switching PWM Full-bridge converter which incorporates active power switches in series with each rectifier diode in transformer secondary side. Switching and conduction losses of all the switches and devices are reduced as well as commutating current and circulating current flowing through transformer as compared with conventional converter. And duty ratio of primary switches is constant for maximum voltage conversion ratio. But this converter can be varied output by duty ratio of secondary switches. Operation principles basically the same as that of the PWM Full-bridge converter published previously. The operating characteristics of this converter are illustrate and discussed including the simulated analysis.

Switched reluctance motor drives have been finding their applications in the variable speed drives due to their relatively low cost, simple and robust structure, controllability and high efficiency. Fuzzy control does not need any model of plant. It is based on plant operator experience and heuristics. Fuzzy control is basically adaptive and gives robust performance for plant parameter variation. This paper deals with the sped control of switched reluctance motor using fuzzy controller with 7-rule based fuzzy logic. The proposed fuzzy controller is superior to the control performance of the conventional PI controller. The fuzzy controller is implemented by 80C196KC, 16 bit one-chip microcontroller.

Generally, The systems are so complex that it not possible to obtain reasonable model using physical insight. Also a model based on physical insight contains a number of unknown parameters even if the structure is derived from physical laws. To solve these problems, the systems identification is described in this paper. So, AC servo motor system which has both open loop and closed loop is selected as an example for identification. A state-space model of AC servo motor system is identified through open loop experiment and identified through closed loop experiment and using pole placement integral controller to open loop system. As the results, From ARMA model, We have obtained continuous-time state space model.

In this paper, a plate type ozonizer has been designed and manufactured to minimize the size of ozonizer. This ozonizer have following benefits: convenience of shift and installation maximize space utility. Therefore, ozone generation characteristics have been investigated by varying flow rate, supplied power and gap spacing of plate electrodes.

In this paper, the removal rate of NO in a reactor is measured first using nonthermal plasma generated from a wire-cylinder type reactor, then the spatial density distribution of NO particles is investigated using ICCD(Intensified Charged Coupled Device) camera. This research uses nonthermal plasma from electrical discharge to analyze the NO characteristics, and the measurements of NO discharge image and Distribution are performed using the ICCD camera to examine the NO characteristics more closely. Furthermore, the method of Laser Induced Fluorescence (LIF) is used to analyze the particular behavior of NO particles more specifically, to suggest a method of reducing exhaust gas, a serious environmental problem.

This paper is a study if control system with KEN that is not only superior-manufacture ability-hardware; that is to say, the hardware is HMI/SACD solution and it has been developed to sub-station and power management system, which is easy, fast and suitable for users to work with, but also compatible solution with domestic environment Futhermore, the hardware has been developed by completely domestic technology with knowledge from various actual experiences. In the long run, for uninterruptible power supply to train, building, and factory, real time tele-supervisory control to power facilities.

This paper presents a ripple reduction of BLDC motor using TMS320F240. A fault of permanent magnet(PM) BLDC motor possible to miniaturization and high-output is to be difficult to reduce speed-ripple at low speed region. An existing solution is to be use of PWM waveform by PI control with computing control angle of 60$^{\circ}$. The new family of DSP controllers provides a single chip solution by integrating on-chip not only a high computational power but also, all the peripherals necessary for electric motor control. This paper gives an advanced solution of the SVPWM technique for the purpose of reducing control angel rather than 60$^{\circ}$. This technique gives an excellent speed ripple characteristic.

This paper describes a double-ended current fed push-pull type high frequency resonant inverter used as the power supply for wax-sealing. The proposed inverter can realize ZVS operation by using resonant capacitor to ZVS capacitor and has some merits not only reduction of switch current distribution but also extension of load range compare to the conventional single-ended current fed push-pull type high frequency resonant inverter. This analysis of proposed circuit uses normalized parameter ad characteristic estimation which is needed in each step before design is generally described according to normalized frequency($\mu$), normalized resistance(λ) and parameters. It is also presented as an example of method of the circuit design based on estimation analysis values from theoretical analysis. The theoretical analysis is proved through experiment and this circuit shows that it can be used practically as the power supply system for wax-sealing and DC-DC converter.

The corona in oil, the surface discharge in oil, the void discharge which could be in a transformer were imitated by using three electrodes with different shapes and the frequency bands of each ultrasonic signal were measured. After emitting artificial noises toward the transformer, only ultrasonic signals were extracted by frequency filtering, from the ultrasonic signals with noises at partial discharge. As a result, it was confirmed that the ultrasonic signals due to the corona in oil, the surface discharge in oil, the void discharge could be distinguished from the noises.

This paper presents the reasonable method for electric power management through efficient use of electricity. With a rapid of national economics and living standard, electrical energy consumption markedly increased. Especially it is increased electrical energy consumption in commercial buildings and thus an energy conservation through efficient use of electricity became more important.

In this paper, VHF(30~230[MHz]) electromagnetic waves radiated from partial discharge(PD) at two-type electrodes in air are measured and the peculiar patterns of their spectra are reported. Also, the polarization and distance characteristics of electromagnetic wave rediated by PD, were investigated. In case of epoxy insulator in inserted, the noise level of radiated electromagnetic waves is 0.6~6.2[dB] higher than the case in air at below 90[MHz]. The frequency spectrum distribution of radiated electromagnetic waves appears different in the whole frequency range according to the arrangement of antenna.

In this paper, Frequency spectra of AE(acoustic emission) signals generated from the magnetizing and the load currents in the actual operating cast-resin power transformer of 500[kVA] under distribution system of22.9[kV] were also analysed to distinguish the AE signals due to void discharges from the magnetic circuit noises in the core of cast-resin power transformer. As the experimental results, we could distinguish the AE signals whether those signals were caused due to the void discharges or due to the magnetic circuit noises by analyzing the frequency spectrum of AE signals. Frequency spectra of AE signals generated from the cast-resin power transformer in operation due to both the magnetizing and the load currents appeared in the range of 40-120[khz].

The assessment of the condition of a transformer winding which is suspected of having suffered short circuit damage can be difficult. Conventional test such as winding resistance, magnetisation current or insulation resistance will only detect damage if a permanent electrical fault exists. Visual inspection of windings necessitates the removal of oil and in many cases only a very small proportion of the winding can be seen. We describe the characteristics. As the front rise time of recurrent-surge generator pulse less than 1000ns and the peak value of pulse is about 500V, we have the good results of detecting winding deformation in the LVI test of transformers.