• Title/Summary/Keyword: AGC

Search Result 279, Processing Time 0.027 seconds

A Study on the Frequency Bias Setting of the AGC based on Frequency Response in Korea (전력계통 주파수응답 실적 기반의 국내 AGC 주파수 바이어스 설정치 산정에 관한 연구)

  • Kang, Bo-Ram;Kwon, Han-Na;Kook, Kyung-Soo
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.64 no.7
    • /
    • pp.978-983
    • /
    • 2015
  • This paper presents Frequency Bias setting for the adequate AGC(Automatic Generator Control) operation based on the frequency response of power system in Korea. AGC frequency control recovers the frequency up to 60Hz following a primary control when the frequency suddenly drops due to a fault in power system. AGC can compensate an appropriate amount of generation by calculating ACE(Are Control Error) from the frequency deviation with the AGC frequency bias set from the actual frequency response in power systems. An appropriateness of the proposed AGC bias setting is verified through case studies employing the simulation model.

An Enhanced AGC Structure and P-SCH Detection Method for Initial Cell Search in 3GPP LTE FDD/TDD Dual Mode Downlink Receiver (3GPP LTE FDD/TDD 듀얼 모드 하향 링크 수신기의 초기 셀 탐색을 위한 개선된 AGC 구조 및 P-SCH 검출 기법)

  • Chung, Myung-Jin;Jang, Jun-Hee;Choi, Hyung-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.35 no.3C
    • /
    • pp.302-313
    • /
    • 2010
  • In this paper, we propose an enhanced AGC (Automatic Gain Control) structure and P-SCH detection method for initial cell search in 3GPP (3rdGenerationPartnershipProject) LTE (Long Term Evolution) FDD(Frequency Division Duplex) / TDD (Time Division Duplex) dual mode system. Since TDD frame structure consists of uplink subframe and downlink subframe, conventional AGC structure causes P-SCH detection performance degradation by increase of AGC variation due to signal power difference between uplink and downlink subframe. Also, P-SCH detection performance is degraded by distortion of P-SCH correlation characteristic in frequency offset and multipath fading channel environments. Therefore, we propose an AGC structure which can minimize P-SCH detection performance degradation with stable operation in 3GPP LTE TDD mode as well as FDD mode. Also we propose a P-SCH detection method which can reduce distortion of correlation chareteristics in frequency offset and multipath fading environments and obtain good P-SCH detection performance. Simulation results show that the proposed AGC structure and P-SCH detection method have stable AGC operation and excellent P-SCH detection performance for 3GPP LTE TDD / FDD dual mode downlink receiver in various channel environments.

An Implementation of Fuzzy Automatic Gauge Control for the Plate Steel Rolling Process (후판 압연공정에서 퍼지 두께제어 구현)

  • Hur, Yone-Gi;Choi, Young-Kiu
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.15 no.6
    • /
    • pp.634-640
    • /
    • 2009
  • The plate manufacturing processes are composed of the reheating furnace, finishing mill, cooling process and hot leveling. The finishing rolling mill (FM) as a reversing mill has produced the plate steel through multiple pass rolling. The automatic gauge control (AGC) is employed to maintain the thickness tolerance. The high grade products are forming greater parts of the manufacturing and customers are requiring strict thickness margin. For this reason, the advanced AGC method is required instead of the conventional AGC based on the PI control. To overcome the slow response performance of the conventional AGC and the thickness measurement delay, a fuzzy AGC based on the thickness deviation and its trend is proposed in this paper. An embedded controller with the fuzzy AGC has been developed and implemented at the plate mill in POSCO. The fuzzy AGC has dynamically controlled the roll gap in real time with the programmable logic controller (PLC). On line tests have been performed for the general and TMCP products. As the results, the thickness deviation range (maximum - minimum of the inner plate) is averagely from 0.3 to 0.1 mm over the full length. The fuzzy AGC has improved thickness deviation and completely satisfied customer needs.

An Advanced Adaptive Garbage Collection Policy by Considering the Operation Characteristics (연산 특성을 고려한 향상된 적응적 가비지 컬렉션 정책)

  • Park, Song-Hwa;Lee, Jung-Hoon;Lee, Won-Oh;Kim, Hyun-Woo
    • IEMEK Journal of Embedded Systems and Applications
    • /
    • v.13 no.5
    • /
    • pp.269-277
    • /
    • 2018
  • NAND flash memory has widely been used because of non-volatility, low power consumption and fast access time. However, it suffers from inability to provide update-in-place and the erase cycle is limited. The unit of read/write operation is a page and the unit of erase operation is a block. Moreover erase operation is slower than other operations. We proposed the Adaptive Garbage Collection (called "AGC") policy which focuses on not only reducing garbage collection process time for real-time guarantee but also wear-leveling for a flash memory lifetime. The AGC performs better than Cost-benefit policy and Greedy policy. But the AGC does not consider the operation characteristics. So we proposed the Advanced Adaptive Garbage Collection (called "A-AGC") policy which considers the page write operation count and block erase operation count. The A-AGC reduces the write operations by considering the data update frequency and update data size. Also, it reduces the erase operations by considering the file fragmentation. We implemented the A-AGC policy and measured the performance compared with the AGC policy. Simulation results show that the A-AGC policy performs better than AGC, specially for append operation.

Design and Implementation of Real Time AGC for Satellite TDMA Communication Systems (위성 시분할다중접속 통신시스템을 위한 실시간 자동이득제어기 설계 및 구현)

  • Lee, Huisoo
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.38B no.4
    • /
    • pp.298-304
    • /
    • 2013
  • Channel attenuation must be taken into account when designing Time Division Multiple Access(TDMA) communication systems. In addition, Automatic Gain Control (ACG) is a requirement in satellite communication systems in order to form a stable network regardless of rapidly changes in channel environment. In this study, we present an AGC with possible real-time application to time slots in satellite TDMA communication systems. A satellite TDMA system was designed and implemented in order to test the performance of the proposed real-time AGC, and the system's BER (Bit Error Rate) was found by applying the proposed AGC algorithm. These results can be expected to be of high value in improving the stability of satellite TDMA communication systems in the future.

A Study on Rolling Mill Dynamics Model and Automatic Gauge Control System

  • Kim, Tae-Young;Kwon, Dae-Hyun;Choi, Won-Ho
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2004.08a
    • /
    • pp.120-125
    • /
    • 2004
  • In the rolling of steel or non-steel metal the most important quality aspect are thickness and flatness. In thickness, there are two important factors. One of them is getting close with accurate goal, nominal gauge, the other is minimize gauge bandwidth, the variation in gauge. In this thesis, we proposed the fuzzy model AGC to minimize gauge variation along the length, developed the rolling mill dynamic model using the math mode of the rolling mill process and the rolling model related with the variety character of the rolling material. We compared the gauge control efficiency of fuzzy model AGC and PI mass flow AGC. We have got a simulation result, that the exit gauge variation of PI mass flow AGC was 2 micron and fuzzy model AGC was 1.2 micron at 1200mpm of rolling speed when each controller was rolling 5 micron of material that is the entry gauge variation.

  • PDF

Dynamic Simulation of AGC/LPC Synthetical System for Hot Strip Finishing Mill

  • Wang, Xiaoying;Wang, Jingcheng
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • v.8 no.1
    • /
    • pp.24-30
    • /
    • 2008
  • A simulation of hot strip finishing mill automatic gauge control (AGC) system is built, which is divided into four modules such as rolling mill system, AGC module, looper system and strip model. The rolling mill system is built by mechanism modeling, the looper system and strip model are built by function modeling, and the AGC model is tried to use intelligent control of a multi-function AGC system. The target is attempted to use this simulation object to minimize finisher exit strip thickness deviation resulting from strip entry thickness disturbance and rolling force deviation. Simulation results show that the result of this AGC/LPC synthetical system module simulation is quite close to the actual result. The simulation system can also analyze most kinds of disturbance which affect the rolling process. It is proved that the system can represent practical situation of hot strip finishing mill process control, and be used as a basic platform of research and development for researcher and engineer.

Design of AGC and DC Offset Remover for Cable Modem (케이블 모뎀을 위한 AGC 및 DC offset Remover 설계)

  • 김기윤;최형진
    • Proceedings of the IEEK Conference
    • /
    • 1999.11a
    • /
    • pp.775-779
    • /
    • 1999
  • This paper presents design of AGC(Automatic Gain Control) and DC offset remover suitable for cable modem which makes use of QAM(Quadrature Amplitude Modulation) scheme. Since QAM has multi-level signal characteristic, for high-order QAM, the constellation is dense and the distance of decision boundary between adjacent symbols is short. So AGC and DC offset remover must be designed optionally for preventing performance degradation. AGC is designed into feedback type and is related to the STR(Symbol Timing Recovery)and Paff interpolation algorithm. Whereas AGC need to perform average power detection during many symbols by comparison with the reference power, DC offset remover uses only the instant polarity decision such that simple implementation can be achieved with good performance. Though the AGC and DC offset remover are simulated here only for 256 QAM scheme for convenience'sake, it can be applied to other multi-level QAM or PSK modulation scheme.

  • PDF

A Low Voltage, Digital Automatic Gain Controller (비디오 시스템을 위한 저전압, 디지털 자동이득 조절기)

  • 권진호
    • Proceedings of the IEEK Conference
    • /
    • 2000.06e
    • /
    • pp.183-186
    • /
    • 2000
  • In this paper we propose a new architecture of a programmable digital automatic gain controller(AGC) for analog interface in mixed mode systems. Compared with conventional analog AGCs which have difficulties in integration due to large capacitors, the proposed AGC is easily integrated. So the production cost can be reduced. In addition, The proposed AGC has a better performance in temperature, and power supply variations, and substrate noise than analog counterparts do. To prevent erroneous operations of the AGC due to noise, a mal-function preventer is newly proposed. In addition, to achieve an optimized AGC time constant, we propose a logic block which controls an up-down counting clock. This is directly related to the changing speed of the AGC gain. Implemented with a 0.25 $\mu\textrm{m}$ 1-poly, 5-metal CMOS parameters, the AGC operates from a single 2.5V power supply with the dynamic range of 36.ldB and occupies active area of 500$\mu\textrm{m}$${\times}$600$\mu\textrm{m}$

  • PDF

Consideration on the Effect of Setpoint AGC Command and Related AGC Logic in DCS (설정점 제어방식의 AGC 지령 및 발전소 DCS의 관련로직 변경방안)

  • Jeon, Dong-Hoon;Kwon, Soon-Man;Lee, Hyo-Sang;Shin, Joong-Seon
    • Proceedings of the KIEE Conference
    • /
    • 2001.07a
    • /
    • pp.395-397
    • /
    • 2001
  • A new automatic generation control (AGC) signal transmission format will be adopted in the new energy management system (EMS) that KEPCO is planning to install for managing and operating the power system efficiently under the deregulation environment. Therefore, it is necessary for the power plants to make the AGC processing logic fit the new AGC signal flow format. In this work, we compare the new signal transmission scheme with the conventional one in view of its effect to the signal flow in the distributed control systems (DCS) that ale equipped in power plants to handle AGC operation. Then we propose a basic logic configuration for DCS that can be used with the new signal format. In the design of the configuration, some practical issues that should be discussed for the proper operation of the plants are considered.

  • PDF