• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1139_1141
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• 2009

Distributed Generation (DG) is predicted to play a important role in electric power system in the near future. insertion of DG system into existing distribution network has great impact on real-time system operation and planning. It is widely accepted that micro turbine generation (MTG) systems are currently attracting lot of attention to meet customers need in the distributed power generation market In order to investigate the performance of MT generation systems, their efficient modeling is required. This paper presents the modeling and simulation of a MT generation system suitable for grid-connected operation. The system comprises of a permanent magnet synchronous generator driven by a MT. A brief description of the overall system is given, and mathematical models for the MT and permanent magnet synchronous generator are presented. Also, the use of power electronics in conditioning the power output of the generating system is demonstrated. Simulation studies with MATLAB/Simulink have been carried out in grid-connected operation mode of a DG system. The control strategies for grid connected operation mode of DG system is also presented.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2239_2240
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• 2009

This paper describes the design process of three-phase Synchronous generator. stator and rotor were modelled with the result obtained from loading distribution on the provided specification. For proving validity of the result obtained from loading distribution, through Maxwell simulator the first test target values, output and efficiency, Rated speed and etc, were compared with the design result.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.476-479
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• 2009

Unison의 U50 풍력발전기는 실증실험을 거쳐서 상용화 되어 시장에 제품으로 나와 있다. U50에 사용되는 영구자석 동기발전기는 Stator 내경 3.32 m 로 84극을 가지고 있으며 정격 25 rpm으로 운전되는 직접구동형이다. 직접구동형 발전기는 Gearbox 가 불필요한 반면에 높은 torque로 인해서 발전기가 무거운 단점이 있다. 기존의 U50 에 사용되는 발전기는 지지 구조물까지 포함할 경우 총중량이 약 20톤 이상이다. 발전기의 중량을 줄이고 경량화 시키기 위하여 slot에 들어가는 Ampere turn을 증가시키고 turn 수를 증가시켜서 기존과 유사한 전압, 전류, 출력을 유지하면서 축방향 Stator 길이를 감소시킨 최적화 모델에 대한 설계에 대하셔 연구를 진행하였으며 이 보고에서는 그 결과와 절차에 대해서 요약한다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.14-17
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• 2007

Power system restoration following a massive blackout starts with re-energizing primary restorative transmission systems at first. The comparison of the TLCC(transmission line charging capacity) and the RPC(reactive power capability) of related black-start generator should be considered in this stage because overvoltage can be caused by self-excitation at the generator when the RPC is smaller than the TLCC. The RPC can be decided by two criteria. One is stator end core heating, and the other is steady state stability. RPC in steady state stability area has been found based on a synchronous reactance Xd. This paper presents RPC limit of salient pole machine which is different from that of non-salient pole machine in steady state stability area and shows derivation process about that.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.187-192
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• 2007

The terminal voltage of a synchronous generator is maintained by the field current control of excitation system Generally AC/DC converter which is component of AVR(Automatic Voltage Regulator) system for excitation current control is connected to diode rectifier and DC/DC converter system In the case of diode rectifier system of phase controlled converter, AC/DC converter has low power factor and some low order harmonics in the line current. In this paper, two-stage three-phase PWM AC/DC converter is studied to solve these problems, The proposed method is verified by the computer simulations and experimental results in prototype generation system.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.220-222
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• 2002

DG (Distributed Generation) devices such as co-generation systems, fuel cells and photovoltaic power generation systems, etc is introducing into the distribution systems by the deregulation. In this paper, the controller of synchronous generator used for DG is newly designed in order to regulate the real & reactive power and the effect on the islanding phenomenon compared with the traditional controller.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.277-280
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• 1995

A new improved excitation control system for power plant synchronous generators has been developed by KEPRI(Korea Electric Power Research Institute). In this paper a description of the developed control system with detailed design concept is given. Field tests are conducted to show the system performance and to obtain the model parameters. Based on the measurement approached by field tests excitation model parameters supposing a mathmatical model is given can be determinded. This paper also proposes a algorithm of parameter estimation and identification in the synchronous Generator Excitation Control System.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.721-722
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• 2008

This paper deals with comparison and analysis for rotor losses of permanent magnet synchronous generator using phase current harmonic analysis according to dc and ac load. On the basis of analytical field analysis, the rotor losses are analysed. Particularly, rated speed and ac load and the rated speed and dc load conditions are considered. This paper compared rotor losses considered dc load with rotor losses considered ac load. Although our analytical modes is low speed, the rotor losses must be considered by results.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.986-987
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• 2008

This paper deals with the novel type DAVR(digital Automatic voltage Regulator) of the field control system for improving the response and efficiency. The proposed Hybrid type Synchronous Generator consists of permanent magnet which can generate the constant voltage with controlless and field winding. Using Buck-type PWM converter, the response can be improved in the proposed system. The proper operation of the proposed excitation system was verified through the design and experiments.

• Proceedings of the KIEE Conference
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• 2008.10c
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• pp.53-55
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• 2008

In high speed applications, the slotless permanent magnet(PM) motors appear an attractive solution, being almost insensitive to magneto-motive force harmonics and to pulse width modulation(PWM) current ripple and exhibiting lower stator iron losses and rotor losses (significant with square wave current control). So, this paper deals with methods for design of permanent magnet synchronous motor/generator.