• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1304-1308
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• 2005

This paper presents the case that the existing analog control systems were retrofitted with digital DCS(Distributed Control System)s for boiler unit in thermal power plant. Replacement of existing worn-out or obsolete analog control systems has been considered. Replacement of existing analog control systems with another analog control systems has lots of difficulties in maintaining the systems due to being out of stock. Due to those difficulties, existing analog control systems have been retrofitted with digital DCSs in many industrial sites. KEPRI(Korea Electric Power Research Institute) accomplished the project that retrofitted analog control systems with the developed DCSs for boiler unit in middle-scale coal-fired thermal power plant. The benefits of an upgrade to digital control include a increase of reliability due to system redundancy, ease of modifying the control logic and the parameters of function block, ease of maintenance due to available spare parts, improvement of information display, ease of modifying MMI(Man Machine Interface) displays, a increase in system availability, and improvement of control performance. This paper describes how to use the parameters of existing analog controllers, the implementation of digital PID controller, control system configuration for boiler unit in thermal power plant, some boiler control loops, control result during commissioning, and the comparison of boiler characteristic test data after retrofitting with the existing test data.

• Korean Journal of Computational Design and Engineering
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• v.20 no.1
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• pp.36-43
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• 2015

Recently, a number of evaluation studies on availability of plant were carried out. This study was conducted to verify of the reliability of a simulation with some variable such as configuration of process, failure probability density function and the number of iteration times for the natural gas liquefaction plant. The error rate of the KICT-RAM solution was evaluated as 0.03~1.79% compared with the result of the MAROS(commercial solution). And the error-rate change was observed in the range of 0.03~1.75 on the condition of the iteration times as 30, 100, 250. As a result the plant availability evaluation approach of KICT-RAM solution was verified as reasonable. However, the careful approach was required to use the solution because the error-rate increased according to iteration times change.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.2
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• pp.61-68
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• 2014

Function of battery bank stores energy for DC load in general, and DC power system of the nuclear power plant is used to supply DC loads for safety- featured instrumentation and control such as inverter, class 1E power system control and indication, and station annunciation. Class 1E DC power system must provide a power for the design basis accident conditions, and adequate capacity must be available during loss of AC power and subsequent safe shutdown of the plant. In present, batteries of Class 1E DC power system of the nuclear power plant uses lead-acid batteries. Class 1E batteries of nuclear power plants in Korea are summarized in terms of specification, such as capacity, discharge rate, bank configuration and discharge end voltage, etc. This paper summarizes standards of determining battery size for the nuclear power plant, and analyzes duty cycle for the class 1E DC power system of nuclear power plant. Then, battery cell size is calculated as 2613Ah according to the standard. In addition, this paper analyzes performance test results during past 13 years and shows performance degradation in the battery bank. Performance tests in 2001 and 2005 represent that entire battery cells do not reach the discharge-end voltage. Howeyer, the discharge-end voltage is reached in 14.7% of channel A (17 EA), 13.8% of channel B (16 EA), 5.2% of channel C (6 EA) and 16.4% of channel D (19 EA) at 2011 performance test. Based on the performance test results analysis and size calculation, battery capacity and degradation by age in Korearn nuclear power plant is discussed and would be used for new design.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.7
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• pp.285-295
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• 1986

This study is to investigate the stability of expanded new generator plant depending on the capacity of existing system. We examined the transmitting power limit to the existing system as its capacity increase for the various system configuration with fixed location of plants and substations. The results show that the stability has decreasing tendency when the existing source capacity increase. Thus it can be concluded that new generator has little stability problem when it connected to small system, whereas large existing system capacity gives remarkable difficulty in adopting new generator.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.73-76
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• 1996

This paper presents a dynamical anti-reset windup (ARW) compensation method for saturating control systems with multiple controllers and/or multiloop configuration. By regarding the difference of the controller states in the absence and presence of saturating actuators as an objective function, the dynamical compensator which minimize the objective function are derived in an integrated fashion. The proposed dynamical compensator is a closed form of the plant and controller parameters. The proposed method guarantees total stability of resulting system. An illustrative example is given to show the effectiveness of the proposed method.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.69.6-69
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• 2002

The optimal byproduct gas supply system was developed for the optimal management of the byproduct gases in the iron and steel making process based on EXCEL environment. It supplies optimal byproduct gas distribution result as well as analysis including expected electricity generation, holder level change, amount of oil consumption, energy distribution to each boiler, and efficiency of energy resource. To reflect the changing environment of the plant such as maintenance, the system was developed to easily change the optimization model for changing configuration of the system. To verify the performance of the system , case studies for various situation was performed with the developed system, a...

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2000.04a
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• pp.275-280
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• 2000

설계 및 엔지니어링 단계에서 설계정보 전자문서관리 시스템을 통한 지식 수집과 축적의 방법을 제시한다. EDM을 이용한 클라이언트/서버 형태 및 웹 버변의 데이터베이스 인터페이스를 설계하며 이를 통한 발전소 정보의 접그니, 저장, 버젼별로 관리 및 이관/복구/백업하도록 하는 시스템 구현방법에 대해 기술한다. 또한 3차원 캐드 뷰어와 연동된 자료의 효율적인 관리방법에 대해 설명한다.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.33 no.1
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• pp.17-20
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• 1984

The motivation in this paper is in constructing the controller with faster adapting speed than the one using the errors between the states of the plant and the model as the adaptive criterion. In the first part of this work, the adaptive law is found by using the state errors. In the later part, the adaptive law is obtained by introducing the companion model method. Finally the justification for the adaptive speed characteristics are compared.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.806-809
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• 2003

Digital controllers have developed rapidly in recent years. This paper describes the synchronized signal generation circuits for control of Multiple Controllers and test results. Also this paper describes configuration and functions of digital excitation system. The digital excitation system is made up of triple redundancy and has control and protection functions.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.343-347
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• 2001

Advanced Pressurized Reactor 1400(APR-1400), which is a standard evolutionary advanced light water reactor(ALWR), has been developed from 1992 as one of long-term Government Project(G-7). The APR-1400 is designed to operate at the rated output of 4000MWt to produce an electric power output of around 1450MWe. The balance of plant (BOP) for the secondary system consists of main steam, feedwater, condensate, turbine generator and auxiliary system. In this paper, we describe the major design features of secondary component, balance of plant configuration, and then the turbine cycle thermal performance evaluation using PEPSE code.