• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.391-394
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• 2008

Global warming and air pollution have increased the amount $CO_2$ in the atmosphere. In order to decrease the amount of $CO_2$, lots of researches are conducted toward using Hydrogen energy. Because of its high efficiency energy level and environmental friendly features, many companies have researched on developing hydrogen engine system and distributed generation system. Especially, the focus of this research provides the operation method of linear generator for hydrogen fuel combustion linear engine. During an ignition, linear generator is operated by motor to create the initial condition of engine combustion. Once the engine combustion is stabilized, the generator supplies electric power to grid. In order to stabilize the engine, linear generator is required to control mover frequency, direction, and force; Hence the PCS(Power Conversion System) place three H-bridge type inverter stacks in parallel to control phase current independently. As well, by using Back-to-Back method, it can receive electric power from both end.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.7 no.3
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• pp.1-7
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• 2011

The analysis shows that the vibration is one of the main reasons of turbine failure. Especially, the problems caused by vibration occur right after retrofit of the turbine-generator and restarting the turbine. Through the case study of high vibration caused by after the turbine trip and restart, turbine vibration was identified to be influenced by startup condition. Turbine startup at high casing temperature right after unscheduled turbine trip cause radial expansion in rotor by contraction in axial direction, while casing continues to contract by steam flowing into casing. Consequently, gap between rotor and casing decrease until to metal contact to cause high vibration. Through the case study of high vibration of turbine-generator system after generator retrofit, it was identified that generator replacement could cause high vibration in turbine-generator system if the influence of generator replacement on entire system was not considered properly. To prevent startup delay caused by high vibration, it is important to keep the gaps at the design standard and start the turbine after thermal equilibrium.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.2
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• pp.103-107
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• 2009

PI controller is widely used as voltage control system of generator. However when a generator system has various characters of continuance, a new PI parameter decision for accurate control is a hard task as method of solving this problem, in this paper, the method to generator voltage control using Neural Network self adaptive control is presented. A property continuous feedback control gain of voltage control system is decided by a rule of delta learning. The function of proposed control method is verified by voltage control experiment results of DC generator.

• Journal of the Korean Solar Energy Society
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• v.23 no.3
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• pp.29-35
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• 2003

Generator for wind power can be either synchronous or asynchronous (induction) types. Induction and synchronous generators behave in a different way when subjected to severe faults. Induction generators does not have an angle stability limit and short circuit in the neighborhood of an Induction generator causes the demagnetization of the machine when the fault is cleared, the voltage raises slowly, while the grid contributes with reactive power to the generator and the magnetic flux recovers. On the other hand in the synchronous generators the recovery of the voltage is immediate, since the excitation of the rotor angle comes from an independent circuit. This paper shows the result of the transient state analysis in the network connected to wind generation system Several case studies have been conducted to determine the effect of the clearing time of a fault on the network stability. It has been found that the critical clearing time can be as low as 61ms in the case of induction generator compared to 370ms in the case of synchronous generator.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1303-1305
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• 2002

In this study, We proposed high efficiency wind power generator system for induction generator used SVPWM swiching inverter. First, We suggest Equivalient Circuit for Ind Generator, it's characteristics equation, and equation of slip. In addition, we suggest Pick Traction Slip control methods. adapted variable power system. We study simulation result fo suggested system and output power by slip e and we identify SVPWM of suitable wind p system by comparison between SPWM and SVPW Consequently, we show that the control result variable wind power is suitable.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.318-321
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• 2012

This paper presents hybrid power system that consist of Shaft Generators and Diesel Generators, connection of Generator and Bus bar, operating method of Generator and design considerations of control system through parallel operation.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.509-510
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• 2016

본 논문은 계통연계형 인버터의 위상추종기법인 SRF-PLL을 모델링하고, FPGA에 구현하기 위해 System Generator를 이용하여 설계하였다. SRF-PLL의 비례-적분 이득은 소신호 해석을 하여 일반화를 통해 입력전압의 크기에 관계없이 적용가능하며, 주파수 응답에서 65도 위상여유를 갖는 안정한 이득을 산정하였다. FPGA 구현을 위해 MATLAB/SIMULINK와 연동 가능한 System Generator를 이용하여 SRF-PLL을 모델링하였으며, MATLAB 기반의 시뮬레이션과 실험을 통하여 위상추종 특성을 분석하였다.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.6 no.3
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• pp.9-13
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• 2007

In this paper, we propose a system that can be used to provide the national standard time for the general public with ease by using the self-implemented independent time-code generator for transmitting standard time information through both the wired and the wireless networks. The newly proposed time code is different from conventional methods in the point that it has a structural advantage of having an ability of obtaining reliable data by repeatedly transmitting the same information. We observe that it is sufficiently possible to transmit the time information with a microsecond level because measurement result shows that the system uncertainty is about few nanosecond of time-error fluctuation through the self characteristic measurement of total system including the time-code generator and decoder system receiving time-information.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.7
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• pp.352-357
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• 2005

In competitive electricity markets, the System Operator (SO) coordinates the overall maintenance schedules when the collective maintenance schedule reported to 50 by Gencos not satisfy the specified operating criteria, such as system reliability or supply adequacy. This paper presented a method that divides generator maintenance scheduling of the 50 into a master-problem and a sub-problem. Master-problem is schedule coordination and sub-problem is DC-optimal power flow. If sub-problem is infeasible, we use the algorithm of modifying operating criteria of master-problem. And, the 50 should use the open information only, because the information such as cost function of a generator and bidding Price is highly crucial for the strategies of profit maximization.

• Journal of Electrical Engineering and Technology
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• v.6 no.1
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• pp.42-47
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• 2011

Automatic generation control (AGC) is an important function for load frequency control, which is being implemented in Energy Management System (EMS). A key feature of AGC is to back up governors to enhance the performance of frequency control. The governor regulates system frequency in several to ten seconds, while the droop control concept results in steady-state control error. AGC is a supplementary tool for compensation of the steady-state error caused by the droop setting of the governors. As the AGC target is delivered to each generator as an open loop control target, the generator output is not guaranteed to follow the AGC target. In this paper, we introduce generating unit controller (GUC) control block, which has the purpose of enabling the generator output to track the AGC target while maintaining the governor performance. We also address the tuning methods of GUC for better performance of AGC in the Korea Energy Management System (K-EMS).