• 전기학회논문지
• /
• 제59권9호
• /
• pp.1540-1548
• /
• 2010

KEPCO proposes enhanced voltage management system that is a coordinate voltage control system between the hierarchical voltage control system and the slow voltage control system. It has been installing in Jeju island. VMS consists of a master controller, CVC (Continuous Voltage Controller) and DVC (Discrete Voltage Controller). CVC consists of main controller, FDMU (Field Data Measurement Unit) and several RPDs (Reactive Power Dispatcher). CVC has a control scheme with AVRs of generator to maintain the voltage of a pilot bus in a power system, DVC has a control scheme with static reactive power sources, like a shunt capacitor, a shunt reactor, ULTC and so on, to maintain the reactive power reserve of a power system and a master controller is executed to recover reactive power margin of a power system through coordinated control between CVC and DVC.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제17권2호
• /
• pp.353-368
• /
• 2023

The four wing unmanned aerial vehicle owns the characteristics of small size, light weight, convenient operation and well stability. But it is easily disturbed by external environmental factors during flight with these disadvantages of short endurance and poor attitude solving ability. For solving these problems, a microprocessor based on STM32 chip is designed and the overall development is completed by the resources such as built-in timer and multi-function mode general-purpose input/output provided by the master micro controller unit, together with radio receiver, attitude meter, barometer, electronic speed control and other devices. The unmanned aerial vehicle can be remotely controlled and send radio waves to its corresponding receiver, control the analog level change of its corresponding channel pins. The master control chip can analyze and process the data to send multiple sets pulse signals of pulse width modulation to each electronic speed control. Then the electronic speed control will transform different pulse signals into different sizes of current value to drive the motor located in each direction of the frame to generate different rotational speed and generate lift force. To control the body of the unmanned aerial vehicle, so as to achieve the operator's requirements for attitude control, the PID controller based on Kalman filter is used to achieve quick response time and control accuracy. Test results show that the design is feasible.

• 디지털산업정보학회논문지
• /
• 제16권4호
• /
• pp.29-42
• /
• 2020

SCADA (Supervisory Control and Data Acquisition) systems for remote monitoring, data acquisition and control are applied to major industrial infrastructures including power, water and railroad. Recently, there are many researches on key management scheme for secure communication due to change to the open network environment. These systems are located at far distances and are connected to the main control center through various types of communication methods. Due to the nature of these systems, they are becoming the significant targets of cyber attack. We propose an efficient key management scheme which is established on ID-based cryptosystem without an expensive computation on MTU (Master Terminal Unit), Sub-MTU, and RTU (Remote Terminal Unit). The proposed method is secure and effective in key management among multiple legitimate devices.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2001년도 ICCAS
• /
• pp.65.2-65
• /
• 2001

There are not only lots of controllers such as UMC(Unit Master Controller), BMC(Boiler Master Controller), Fuel Flow controller, Air flow controller, Feed water flow controller, S/H R/H Temperature controller and so on, but also compensation controller such as BTU compensator, Fuel/Water ratio controller and O2 Co controller to take automatic control in the super critical once through boiler. It is important to make complete automation of boiler to use the compensation controller like BTU compensator. For example, In case of some boiler condition, operator has to change combustion parameter for changing the coal, on the contrary BTU compensator can calculate set value of the fuel flow and reset the fuel flow demand by itself. This paper shows us the logic and instruction regarding compensation controller of boiler that can be operated automatically.

• Journal of Biosystems Engineering
• /
• 제29권2호
• /
• pp.159-166
• /
• 2004

In this study, we have developed a web-based management system for greenhouse teleoperation. The remote control system consisted of a database, a web-server, a controller in greenhouse, and clients. The database in the server stored user's information and greenhouse conditions was used to manage user's login and conditioning data. The management system developed by using Java applet, which was a client program for effective and easy management of greenhouse, monitored the greenhouse in real time. Master and driver boards were installed in the greenhouse control unit. Database on flowering to collect and analyze data exchanged data with the server. The master board could be managed effectively by timer routine, repeat control within setting time, and algorithm of setting points. Also, the greenhouse conditions could be controlled by manual or remote controller(PC) through a web browser in internet. Furthermore, all of the control devices of the greenhouse were managed by remote control of using PC and checked via camera installed in greenhouse. Finally, we showed the experimental results of the system which was installed in Pusan Horticultural Experiment Station.

• 플랜트 저널
• /
• 제18권4호
• /
• pp.66-72
• /
• 2023

신재생에너지 비중 증가에 따른 전력계통 불안정성과 탈원전, 노후 석탄화력 폐쇄로 인한 안정적인 발전자원 감소에 대한 대응 방안으로 터빈제어밸브 4개중 2~3개를 교축하여 발전기 출력 증·감발과 주파수를 추종하는 복합 변압 운전 방식을 터빈제어밸브를 전개하여 교축손실을 줄임으로서 발전 효율을 극대화하는 순 변압운전 방식으로 대체하고, 계통 주파수 변동에 신속하게 대응하기 위해 ESS를 연계하여 주파수 추종 및 자동발전운전을 하는 제어로직을 500MW 석탄화력인 태안 5호기를 대상으로 개발하였다. ESS 운전(신속한 응답, 용량 한계)과 발전소 터빈제어밸브 교축 운전(느린 응답, 지속적인 운전)의 장·단점을 보완하는 협조제어 알고리즘이 실제 발전소에 적용시 발전 효율 향상은 물론 전력 수요에 신속하고 유연하여 대응하여 계통 안정성에 기여할 것으로 확신한다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
• /
• pp.284-287
• /
• 1987

In this paper, the design and implementation of a multiprocessor based Die Bonder Machine for the semiconductor will be described. This the partial research result, that is, the 1st year portion of the project to be performed for a period of two years from June, 1986 to May, 1988. The mechanical system consists of the following three subsystems : (i) transfer head unit, (ii) die feeding XY-table unit, and (iii) plunge up unit. The overall control system is designed to be essentially a master-slave type in which each slave is functionally fixed in view of software and also the time shared common bus structure with hardwired bus arbitration scheme is utilized, the control system consists of the following three subsystems each of which employs a 16 bits microprocessor MC 68000 : (i) die bonder processor controller, (ii) visual recognition/inspection and display system, (iii) the servo control system. It is reported that the proposed control system were applied to Working Sample and tested in real system, and the results are successful as a working sample phase.

• 한국주거학회논문집
• /
• 제20권4호
• /
• pp.39-47
• /
• 2009

The purpose of this study is to find out the changes on the metropolitan condominium apartment unit plans based on the interior spaces related to women such An-bang (master bedroom), bathroom and attached spaces to the master bedroom, living room, diningroom, kitchen, utility room, and balcony. This study used the content analysis method and space syntax. Contents were limited to the floor plans with 3 rooms type and about 105 m2 in the Korean apartment encyclopedia. The unit plans of 2,278, built from October 1975 to January 2008, were analyzed and basically SPSS package 16.0 was employed. The results were as followed. 1) Living room was a core space and an increasing tendency. After 2001, the design trend of living room connected with kitchen and dining room, and dining room changed into one space combining with women's working space such kitchen. It meaned women's working activities became into family public activities as to depending open access. 2) Kitchen had a characteristics that was connected to utility room or back balcony, and the number of extra kitchen increased. Also, the size of DK decreased, but utility size little increased. It was showed the characteristic of this space was still for women. 3) An-bang had a little strong characteristics of married coulpe or women's personal space with bathroom or dress room/powder room. 4) In addition, the values of integration and control of living room and DK were highest. It meant these space were centered in unit plans. Next, the An-bang and dress room/powder room were high. Utility room or balcony's were next, and these were women's working space. Therefore, family's public space was most important, and married couple or women's personal and working space were later in planning.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 추계학술대회 논문집 전력기술부문
• /
• pp.382-384
• /
• 2008

D-TRS is a method of wireless communication. This method will be able to use several frequency for multiple user used chanel together. TETRA of D-TRS technology is not rented network. Using TETRA network has the strong point which cost better than CDMA network of rental network. Master server of SCADA(Supervisory Control And Data Acquisition) system is realtime supervise control and a data acquire the control system or the RTU(Remote Terminal Unit). The present paper is developed and proposal the gateway platform for electronic power backbone network based on D-TRS. This gateway platform is converted DNP3.0 messages with TETRA PDU and converted TETRA PDU with DNP3.0 messages. Master server and FRTU will be able to send and receive DNP3.0 message via TETRA network using this gateway platform.

• 전기전자학회논문지
• /
• 제17권3호
• /
• pp.267-274
• /
• 2013

본 논문은 Pulse Frequency Modulation(PFM)/Pulse Width Modulation(PWM) 듀얼 모드 피드백 기반 LED 백라이트 유닛 구동용 LLC 공진 변환 제어 IC 설계에 대한 내용을 제시한다. 공진형 변환기에서 하나의 변압기를 사용하면서, 두 가지 출력 전압을 생성할 수 있는 구조를 제안하였으며, Master 출력은 PFM 방식으로 Slave 출력은 PWM 방식으로 제어하도록 설계 하였다. 2차 측 Master 출력을 제어하기 위해서 파워 스위치 제어 신호의 주파수를 조절하는 PFM 피드백과 2차 측 Slave 출력을 제어하기 위해서 파워 스위치 제어 신호의 펄스 폭을 조절하는 PWM 피드백 회로를 설계하였다. 설계된 IC는 $0.35{\mu}m$ 2 Poly 3 Metal BCD(Bipolar-CMOS-DMOS) 공정을 이용하여 레이아웃 되었으며, 면적은 $2.3mm{\times}2.2mm$ 이다. 또한, 설계한 칩은 5 V 공급 전압으로부터 26 mA의 전류를 소모하였다.