• 전기학회논문지
• /
• 제62권3호
• /
• pp.431-436
• /
• 2013

A neutral section is installed around feeding substation(SS) and sectioning post(SP) that M phase and T phase are isolated in AC feeding system. Electric Train under "Notch-OFF" is operated by inertia within the neutral section. It causes disturbing the operation of electric trains for speed drop and driver's mistakes. A automatic changeover system with thyristor recently have taken under development. In the paper, it is introduced the configuration of train detection system and performance testing on automatic changeover system..

• 한국컴퓨터정보학회논문지
• /
• 제17권12호
• /
• pp.31-39
• /
• 2012

본 논문에서는 수용가의 에너지 절감과 최대수요전력 제어를 위하여 마이크로프로세서를 이용한 자동 전압 조정기(AVR)를 제안한다. 제안한 자동 전압 조정기(HS-AVR : Hybrid Switching Automatic Voltage Regulator)는 토로이달 코어에 1개의 직렬 권선과 분리된 4개의 분로 권선으로 구성되어 있는 단권변압기를 사용한다. 변압기의 전압 조정은 직렬 권선과 분로 권선의 연결 방법에 따라 감압/승압이 가능하다. 스위치는 릴레이와 트라이악을 병행하여 사용한다. 스위치의 조작 시 발생하는 권선의 여자돌입전류를 제어하기 위하여 트라이악을 이용하여 연결 상태를 변경하고, 연결 상태 유지 시에는 릴레이를 이용함으로써 스위치 소비 전력을 최소화 한다. 제어 신호는 여자 돌입 전류를 줄이기 위하여 전압 파형에 동기화 하여 제어되며 이를 위하여 소프트웨어 PLL을 사용한다. 소프트웨어 PLL은 전압 파형의 제로크로스, 전압 최고점 등의 동기화에 사용함으로써 스위치와 시스템을 최소화한다. 기존 전압 조절 스위치나 자동 전압 조정기 구조는 여자 돌입 전류로 인한 스위치 접점 손상을 막기 위하여 최대전류를 수용할 수있는 용량으로 구성함으로써 장치 크기가 매우 커지는 문제점이 있었다. 본 논문은 이런 문제를 해결하여 자동 전압 조정기의 크기를 줄이고 효율을 높이는 방법을 제안하였다.

• 한국인터넷방송통신학회논문지
• /
• 제23권4호
• /
• pp.143-148
• /
• 2023

SRM의 특성 중 비선형성으로 인해 최대토크 및 최소 토크 맥동 형성을 위한 적정 운전이 어렵다. 또한 고정 스위칭각 제어 때 속도 가변에 따른 토크 형성이 불안정하여 효율을 저하시키는 문제점을 가지고 있다. 따라서 속도 가변에 따른 능동적인 스위칭각 제어가 필요하다. 본 논문에서는 SRM의 비선형성으로 인한 문제점으로부터 선행각 (Advance angle)의 자동제어에 의한 토크 리플 저감과 이에 따른 출력 토크 향상에 의한 구동 성능개선을 위한 방법에 대해 모색하였다. 또한 히스테리시스 전류제어기 성능에 따른 스위칭 가변으로 인한 SRM의 최적 운전에 대해 살펴보았다.

• 한국축산시설환경학회지
• /
• 제8권2호
• /
• pp.63-72
• /
• 2002

In Korea, a need of automatic dairy farm management system has been increased to lower production cost and to strengthen international competition. However, the present management system was mostly relied on foreign technologies and caused some problems in post management and after-sales services. Therefore, though there is a problem of price and quality at present, domestic technologies of the management system should be developed for the long run. This study was conducted to develop an electronic identification unit for an automatic dairy farm management system. The developed system was consisted of a tag, a reader, a switching circuit, and a personal computer. The tag attachable to each individual cow was developed to transmit individual radio frequency(RF) code into the air with modulation of ASK(amplitude shift keying). And the switching circuit was added to avoid confusion on reception and transmittance. The reader attached to a feeding device was developed to transmit activating signal periodically and to identify code of the individual tag when the tag was approached to the device. The reader was consisted of an active filter, a detecter, a comparator and a microcontroller. The test result was feasible enough to apply it for the automatic farm management system and the identified maximum distance was about 37cm.

• International Journal of Control, Automation, and Systems
• /
• 제4권6호
• /
• pp.669-681
• /
• 2006

In this work, a new method of design adaptive controllers for SISO systems based on multiple models and switching is presented. The controller selects the model from a given set, according to a switching rule based on output prediction errors. The goal is to design, at each sample instant, a predictive control law that ensures the robust stability of the closed-loop system and achieves the best performance for the current operating point. At each sample the proposed control scheme identifies a set of linear models that best characterizes the dynamics of the current operating region. Then, it carries out an automatic reconfiguration of the controller to achieve the best possible performance whilst providing a guarantee of robust closed-loop stability. The results are illustrated by simulations a nonlinear continuous and stirred tank reactor.

• 제어로봇시스템학회논문지
• /
• 제4권4호
• /
• pp.458-463
• /
• 1998

This paper presents an autopilot design method for STT missiles using the intelligent control technique and multiple controllers. The mixed $H_2/H_{\infty}$ control technique is applied for each controller design and the control gains are implemented by using the genetic searching algorithm. To facilitate automatic switching of multiple controllers under different operating conditions, an error based switching scheme is also combined with the multiple controllers at a higher level, which constitutes a hierarchical intelligent control system. It is shown via computer simulation that the proposed autopilot outperforms the conventional one.

• 대한산업공학회지
• /
• 제42권4호
• /
• pp.290-295
• /
• 2016

This paper proposes a new method for the automatic detection of atrial fibrillation (AF), using Markov regime switching GARCH (1, 1) model. The proposed method is based on the observation that variability patterns of heart rate intervals during AF significantly differ from regular patterns. The proposed method captures the different patterns of heart rate intervals between two regimes : normal and AF states. We test the proposed method using Massachusetts Institute of Technology-Beth Israel Hospital (MIT-BIH) atrial fibrillation database, and demonstrate the effectiveness of the proposed method.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 2010년도 한국컴퓨터종합학술대회논문집 Vol.37 No.1(A)
• /
• pp.269-270
• /
• 2010

• Journal of international Conference on Electrical Machines and Systems
• /
• 제3권4호
• /
• pp.472-480
• /
• 2014

The In solar power system, the height and azimuth of the sun are important parameters which control generated power magnitude. The tracking method that controls the daily generation magnitude according to latitude and longitude using the two axles is often used in the existing sunlight tracking system today. In this two-axle PV track control system, the self-load is concentrated on one FRAME. It is influenced of the regular load, snow load and the wind load, etc. It is difficult to set up the system in the conventional building. This research is a development about the small-scale economy track device of independent load-dispersing solar generation system. The position tracking algorithm is through new coordinates transformation calculating the height and azimuth of the sun.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
• /
• pp.468-468
• /
• 1991

The variable-frequency type water supply equipment, which adopts the variable-voltage and variable-frequency converter(VVVF converter) to govern automatically the rotating speed of a pump, can save 15-20% of power, as compared with a throttle-controlled pump device or an airpressurized water supply equipment, and is finding a wide application. However, it still has some disadvantages : greater pressure fluctuations during switching over the pump and prolonged low-effeciency running of the pump in the case of small consumption of water. Therefore, it is difficult to apply the equipment to the fire water supply system where the water should not be put into use unless a fire takes place, and the water pressure in pipelines should permanently remain constant. This paper introduces the automatic regulation principle of the variable-frequency type air-pressurized water supply equipment (hereafter referred to as simply BFQS equipment) for dual purposes of daily life and fire control, which combined both technologies of speed governing by a converter and air-pressurized water supplying, then discusses some problems related to automatic control, and finally gives the experimental results of an embodiment-BPQS-100-50 water supply equipment.