• Proceedings of the KIPE Conference
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.350-351
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• 2018

본 논문은 가변속 양수발전 시스템의 모델링 및 양수발전용 전력변환장치 제어 구조를 분석하고 모델링하였다. 기존 양수발전 시스템은 동기 발전기를 사용하였지만 신재생 에너지원의 출력 변동 및 부하 변동에 따른 주파수의 변화에 빠른 대응을 위한 가변속 양수발전 시스템을 채용하여 계통 전력과 전압, 주파수 등을 보상한다. 양수 발전소의 터빈, 게이트, 조속기 등을 분석하여 모델링하였으며, Doubly fed induction generator를 위한 back-to-back 전력 변환 장치를 발전 및 양수 모드에 사용하기 위해 벡터제어, 속도제어, 유효-무효 전력 제어기 등을 모델링 하였다.

• Proceedings of the KIEE Conference
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2060-2062
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• 2001

전기를 에너지원으로 사용하는 각 종 부하는 가정, 공장 및 상가 등에 널리 분산되어 있고, 여기에 전기를 생산 공급하는 발전기도 지역적으로 분산되어 병렬운전이 되고 있다. 새로운 발전기가 병렬운전에 참여하기 위해서는 기존 운전되고 있는 전력계통과의 전압, 주파수, 상회전, 위상이 일치하여야 한다. 만약 이들 조건이 갖추어지지 않은 상태에서 임의 병렬 접속을 시도하게 되면 해당 발전기는 물론 전체 계통에 충격과 손상을 초래할 수 있다. 양측의 전압과 주파수 비교는 상용 계측기를 사용하여 비교적 쉽게 할 수 있느나, 상회전 방향과 위상차의 판별에는 세심한 주의가 필요하다. 최근의 발전기에는 병렬 운전 조건을 자동으로 조정, 확인을 하는 장치를 채용하고 있으며 구체적인 회로구성과 동작원리를 여기에서 살펴보았다. 병렬 접속이 이루어진 후 발전기 별 전력 분담과, 계통 주파수 변동에 따라 자동으로 발전기 출력 제어가 이루어지는 기능이 터빈 조속기 측에 설정되어 사용된다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제38권3호
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• pp.249-257
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• 2010

Full authority digital engine control systems for gas turbine engines are replacing conventional mechanical control units rapidly. However, setting up design processes of controllers for high performance helicopter engines are not well known because of the complexity of the total system. This paper presents a high fidelity helicopter and engine simulation for control system design and analysis. Using this environment, a feedforward schedule was set up for a utility helicopter. The total engine simulation with the new controller showed better or equal performance compared to the total engine simulation with the pre-existing controller.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국해양정보통신학회 1999년도 추계종합학술대회
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• pp.467-474
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• 1999

In this paper, Fault tolerant digital governor, using duplex I/O module and triplex CPU module and also 2 out of 3 voting algorithm and adding self diagnostic ability, is designed to realize ceaseless controlling and to improve the reliability of control system. The processor module of the system(SIDG-3000) is developed based on MC68EC040 32 Bit of Motorola, which guaranteed high quality of the module ,and SRAM for data also SRAM for command are separated. The process module also includes inter process communication function and power back up function (SRAM for back-up). System reliability is estimated by using the model of Markov process. The reliability of triplex system in mission time can be improved about 1.8 times in reliability 86%. 2.8 times in 95 %, 6 times in 99 % compared with a single control system. Designed digital governor system is applied after modelling of the steam turbine generator system of Buk-Cheju Thermal Power Plant. Simulation is carried out to prove the effectiveness of the designed digital governor system

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• 제21권10호
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• pp.159-165
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• 2007

This paper presents a method for the derivation of model parameters of a co-generation system using data measured through on-site generator characteristic testing and validates its model parameters. Dynamic models such as generator, excitation system, and turbine/governor are mainly dealt in this paper. For the purpose of validation of derived model parameters, the measured results are compared with simulation results. The comparisons between measured results and simulation results show good match.

• The Transactions of The Korean Institute of Electrical Engineers
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• 제61권10호
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• pp.1399-1411
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• 2012

The grid frequency is controlled cooperatively by the governor of the Turbine-Generator and the automatic generation controller(AGC) of the KPX(Korea Power Exchange). It is a basic requirement that the reliability of the governor is verified to enhance the power system stability but it is not easy to confirm the response characteristics of the governor because all generators are operated in the grid system that has the constant voltage and frequency. Therefore, it is necessary to study a new test method in order to examine the governor dynamic characteristic in the similar fault conditions. A study has shown that it is verified to simulate the turbine-generator power control system, the governor response characteristic under limited conditions and contribution of AGC with the gas turbine generator simulation model as well as demonstrate the dynamic response of the governor with the developed governor dynamic characteristic tester based on digital controller while the turbine-generator is connected to the grid system. This tester is constructed by the built-in functions of the turbine-generator main controller. In this treatise, the theoretical background, development method and the results of both simulations and demonstrations are described as another way to verify the turbine-generator governor dynamic characteristics.

• Corrosion Science and Technology
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• 제21권1호
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• pp.62-67
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• 2022

The objective of this study was to perform failure analysis of an inlet pipe located in a governor valve of a steam turbine in a district heating system. During the operation, the temperature of the governor valve was increased to as high as ~500 ℃, which induced thermal expansion of the inlet pipe along both axial and radial directions. While the inlet pipe did not have contact with the valve seat, the side plane of the upside was constrained by the casing part, which led the inlet pipe to experience stress field in the form of fatigue and creep. The primary crack was initiated at about 30 mm below the top where the complex stress field was anticipated. These results suggest that the main failure mechanism is a combination of thermal fatigue and creep during the operation supported by the observation of apparent beach marks on the fracture surface and pores near the cracks, respectively.