Mobile QR Code QR CODE : Journal of the Korean Institute of Illuminating and Electrical Installation Engineers

Journal of the Korean Institute of Illuminating and Electrical Installation Engineers

ISO Journal TitleJ Korean Inst. IIIum. Electr. Install. Eng.

실내 루버형 집광채광 시스템의 조명 디밍 제어시스템에 따른 실내 조도 분포 분석 Analysis of Indoor Illuminance Distribution by Lighting Dimming Control Systems with Indoor Reflective Louver System

Jiyoung Seo ; Anseop Choi

Lighting dimming systems are used for energy reduction and user convenience in various buildings. However, after installing the dimming system, it is difficult to satisfy the required illuminance of the indoor workplane due to the adjustment of the shading device, the inflow of surrounding lighting system, and daylight. Therefore, this study identified the variations of workplane illuminances by installing and monitoring photosensors in various locations to provide an appropriate luminous environment to users. This study analyzed the energy savings of lighting dimming control systems with the indoor reflective louver system and found that the average energy savings was 29.77%, when the sky condition was partly cloudy. Linear regression analysis was performed using an order least square to determine the relationship with the average illuminance of the working surface of each photosensor. As a result, it was confirmed that the R-squared value for indoor reflective louver system was 0.939 for lighting fixture photosensors, 0.908 for three way photosensors, 0.908 for two way photosensors and 0.779 for wall photosensors.

차단 주파수 가변형 HPF를 이용한 듀얼 3상 인버터의 스위치 개방 고장 검출 기법 Switch Open Fault Detection Technique of Dual Three-Phase Inverter Using Variable Cut-off Frequency HPF

Han-Eol Kim ; Ki-Chang Lee ; Kyung-yub Kim ; Jong-won Park ; Seon-Hwan Hwang

This paper proposes a technique for detecting individual open fault on the top and bottom of a dual three-phase inverter. In general, the switching devices have a high failure rate in the dual three-phase inverter. Especially, the switching devices may fail due to high switching frequency and thermal, electrical, and mechanical stress. As a result, the proposed method normalizes the measured phase currents and detects failures through integrators and HPF with variable cut-off frequency. Therefore, the proposed algorithm can stably detect fault even in the steady state and transient state where the rotor speed is changed. The effectiveness and usefulness of the proposed method are verified through several experiments.

가공지선 불평형전류를 이용한 부하동작 전원용 변류기 제작 및 특성평가에 관한 연구 A Study on the Manufacturing and Characteristics Evaluation of Current Transformer as Power Source for Load Operation Using Unbalanced Currents in Overhead Ground Wires

Sang-Bo Han

In this paper, the design, manufacture, and characteristic evaluation of the current transformer as a power source were discussed to use unbalanced currents flowing through the overhead ground line due to load imbalance in the three-phase four-wire transmission line. In the theoretical calculations on the output characteristics of a current transformer, approx. 30A of the unbalanced current show to produce enough power about 14.7W. And it is confirmed that the battery can be stably charged at 29.7W for the load operation even if the imbalanced current is about 20A. Therefore, it was shown that the current transformer and power supplies developed in this study can be sufficiently used as operating power sources for various loads installed in the transmission line.

입력전압 및 구동주파수 변화에 따른 직렬-직렬 보상 무선전력전송회로의 성능 분석 Performance Analysis of Series-Series Compensated Wireless Power Transfer Circuit according to Input Voltage or Operating Frequency Change

Young-Hoon Choi ; Jae-Jung Yun

In series-series compensated wireless power transfer, input voltage control and operating frequency control methods are used to improve the problem of output voltage change according to load variation. However, if two methods are used to maintain the output voltage, the efficiency of the circuit and the power loss of each element change. Therefore, in this paper, the characteristics, advantages and disadvantages of these methods are compared and analyzed through simulation. For this, the coil and circuit parameters are calculated using COMSOL simulator and design equations to model the circuit, and the performance of the two methods is compared and analyzed with PSIM simulator. In the simulation, when the load changes from 4.5Ω to 9Ω at an output power of 9W to 18W, the output voltage is maintained at 9V by using the input voltage or frequency control methods. As a result of the simulation, the input voltage control method produces an output voltage of 9V in the entire load range by increasing the input voltage even if the voltage gain is not sufficient, and has the maximum efficiency of 86.55% at a load of 4.5Ω. On the other hand, the frequency control method can not produce an output voltage of 9V because the voltage gain is small at a low load, and the circuit efficiency decreases due to an increase in the reactive current at a high load.

재질에 따른 애자의 절연내력특성 분석에 관한 연구 A Study on the Dielectric Strength Characteristics of Insulators According to Materials

Daegu Kim ; Minkyung Jeong ; Hyoungku Kang ; Kibum Suh

In general, insulator is a type of support used to fix and insulate an electric wire to a pylon or electric pole and is made of porcelain, glass, or silicone polymer in a power transmission line or a railway line. In transmission line applications, insulators are exposed to severe electrical and environmental conditions as well as insulation. Insulators are manufactured using various materials, and dielectric strength performance is different depending on the type of material. In this research, the dielectric strength characteristics of insulators according to insulation materials are analyzed by conducting electrical breakdown experiments and finite element method (FEM) analysis. Finally, the degradation characteristics of three types of insulators such as glass, porcelain, and polymer insulators are compared and analyzed through dry flashover and wet flashover experiments. In addition, electric field distribution analysis considering the type of insulator is analyzed by FEM simulation.

미세먼지 포집을 위한 전극이 결합된 복합 정전필터 연구 A Study on a Composite Electrostatic Filter Combined with Electrodes for Collecting Fine Dust

Jae-Seung Jung

This paper is a study on a composite filter that combines an air filter and electrostatic precipitation technology. Basic research on a technology that can improve the dust collection rate by combining an electrode with an air filter with low performance was conducted experimentally. By applying high voltage to the composite filter of the fiber filter and electrode tested in this paper, a dust collection rate for PM0.3 of 83.4% was obtained, which was 6.45 times higher than that of 11.2% when only the fiber filter was used. This clearly indicates that the dust collection performance is improved. In addition, it was confirmed from the experimental results that the power required to improve the filter performance is very low, which indicates that it is advantageous for the maintenance and management of the filter device.

전기설비 절연진단용 원추형센서 Conical Sensor for Insulation Diagnosis of Electrical Equipment

Seok-Gyun Jung ; Eun-Hyeok Choi

Existing power facilities are being maintained through preventive maintenance in various ways. Among them, ultrasonic, thermal imaging, and wireless load monitoring have been mainly used for insulation diagnosis methods of pole transformers, which can be easily accessed in the vicinity. In this paper, in order to compensate for the disadvantages of the existing diagnosis method of pole-type transformers in power facilities, a conical diagnostic sensor was designed that can analyze electromagnetic waves radiated from partial discharge by modeling pole-type transformers and measure electromagnetic waves radiated to the outside. The characteristics of the sensor were confirmed through simulation. The proposed sensor was confirmed to have a return loss characteristic of less than -10dB in the 0.8~2.0GHz band, confirming that it can be used as a sensor for insulation diagnosis.