• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1601-1602
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• 2007

Steam stop valves of steam turbine in the power plant are at their 100% position and have no movements. Steam control valves, ie governor valves have no movements either at their controlling position on load limit operation. By the way, if there were no change of operation state, steam valves could be sticked mechanically. Because the governor could fail in protecting and controlling steam turbine in case of emergency conditions, the closing test of 100% valve travel must be accomplished periodically for the purpose of testimony of their good conditions. And, As the difference between steam turbine structures exists according to the manufacturer or generation capacity, both steam stop valves and steam control valves differes in structure and operation method. Therefore, it is essential for not only turbine protection but also control for the control engineers to find out composition of steam valves and method of closing test.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.110-112
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• 2000

A new robust digital fuzzy controller design methodology is proposed for load frequency of nonlinear power system with valve position limits of governor in the presence of parametric uncertainties. The Takagi-Sugeno (TS) fuzzy model is adopted for fuzzy modeling of the nonlinear power system. A sufficient condition of robust stability for robust fuzzy control with parametric uncertainties is presented in the sense of Lyapunov. The controller that designed by preposed robust fuzzy controller design method is based compounding condition between continues system and discrete system. The effectiveness of controller that designed by the proposed robust fuzzy controller design method is demonstrated through simulation example.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.13 no.2
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• pp.31-37
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• 2017

The heat transfer function or thermal performance is the most important function of the steam generator component in nuclear power plants. The declining of thermal performance, fouling does not affect the electric power of the nuclear power plant within a certain fouling level, but it affects the output when goes beyond the governor valve wide open of the turbine. The VWO steam pressure can be predicted through the thermal performance evaluation of steam generators in the nuclear power plant. In consideration of the fouling characteristics of the steam generator, methods of the thermal performance evaluation and fouling cases are reviewed, and also the critical VWO value is estimated through the actual thermal performance evaluation. It is necessary to apply the VWO theory based on the thermal performance of the steam generators.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1994.05a
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• pp.138-143
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• 1994

A simplified steam generator model has been developed for the simulation of the operational transients of CANDU nuclear power plant. For the analysis of the secondary side, a control volume approach is used and the flow conservation equations are applied for each control volume. The typical steam generator control logic such as the level control and the pressure control are incorporated into the steam generator model with appropriate interface conditions. The steam line including ASDV, CSDV, and governor valve also has been modeled. Test results for typical operational transient case show reasonable transient behavior of steam generator in a real time basis, which is promising for a CANDU engineering simulator.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.05a
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• pp.142-145
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• 2000

A new robust load-frequency control (LFC) methodology is proposed for nonlinear power systems with the valve position limits of the governor in the presence of parametric uncertainties. The Takagi-Sugeno (TS) fuzzy model is adopted for fuzzy modeling of the nonlinear power system. A sufficient condition of the robust stability is presented in the sense of Lyapunov for the TS fuzzy model with parametric uncertainties. The intelligent digital redesign technique for the uncertain nonlinear power system is also studied. The effectiveness of the proposed robust fuzzy LFC controller design method is demonstrated through a numerical simulation.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.5
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• pp.533-540
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• 2013

Prime movers in engine rooms inherently are much affected by the adjustment of their governors for the steady state and transient properties, consequently requiring that marine engineers shall be well familiar with the way to manage governor dials for normal operation. The hydro-mechanical governors basically have different control characteristics and adjustment parameters of stability from digital governors. The former include compensation mechanism using dash pot while the control algorithm of the latter is usually based on the PID action. This study is for configuring a simulation module to let trainees practice how to adjust dials for stability on hydraulic governors in the view that the practice by real governors and engines is time consuming and high cost for operation. The governor module includes the adjusting points such as speed set, speed droop, needle valve and compensation pointer with engine module of $2^{nd}$ order coupled. The results of simulation showed satisfactory responses as a training tool for the adjustment of control parameters.

• Plant Journal
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• v.18 no.4
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• pp.66-72
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• 2023

In order to respond to the demand for flexible operation of thermal power generation, development of natural sliding pressure operation that minimizes throttle loss by opening the turbine control valve 100% and maximize power generation efficiency in conjunction with ESS in order to quickly respond to fluctuations in the system frequency is required. The logic development of natural sliding pressure operation with ESS was developed to modify the existing logic at the power plant's top-level control logic such as the unit master, the boiler master and the turbine master. Cooperative control algorithms that complement the advantages and disadvantages of ESS operation (quick response, limited capacity) and power plant operation (slow response, continuous operation) not only improve efficiency when applied to actual power plants, but also respond quickly and flexibly to load demands to ensure system stability.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.4
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• pp.357-367
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• 2000

A new robust load-frequency control methodology is proposed for nonlinear power systems with valve position limits of the governor in the presence of parametric uncertaines. The TSK fuzzy model is adopted and formulated for fuzzy modeling of the nonlinear power system. A sufficient condition of the robust stabilitry is presented in the sense of lyapunov for the TSK model with parametric uncertainties. The intekkigent digital redesign technique for the uncertain power systems is also studied. The effectiveness of the robust digital fuzzy controller disign mothod is demonstrated through a numerical simulation.

• Journal of the Korean Institute of Gas
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• v.2 no.3
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• pp.70-77
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• 1998

This study proposes a method to facilitate the identification of human error in calling out such qualitative risk assessment in Gas plants. The main idea of this method is based on the scheme of existing qualitative risk assesment technique. The guidewords and tabular worksheet are suggested to be compatible in human error analysis. By using this method developed, the maintenance procedure of Governor system in gas valve station was analyzed to discover the human error in maintenance tasks. As a consequence, certain human errors were identified and the suggested approches proved to be adequate technique for the human error analysis.

• The Journal of Korean Institute for Practical Engineering Education
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• v.3 no.1
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• pp.9-14
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• 2011

The expansion work that is wasted through the irreversible expansion through the PC valve of decompression process of the natural gas governor station can be recovered by replacing the process by an isentropic expansion. The energy and exergy analyses for the two decompression process models of power producing and current decompression process model are presented. Analysis results showed that the exergy by gas supply is 56.29%, the exergy by producing power is 32.12 % in case of preheating system and 22.52% in case of non-preheating system. The dead exergy at the PCV is generated much more network. As these results, the usefulness of exergy analysis is verified.