• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.1
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• pp.42-51
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• 2007

An AC electrical railroad system has rapidly changing dynamic single-phase load, and at a feeding substation, three-phase electric power is transformed to the paired directional single-phase electric power. There is a great difference in electrical phenomenon between the load of AC electrical railroad system and that of general power system. Electric characteristics of AC electrical railroad's trainload are changed continuously according to the traction, operating characteristic, operating schedule, track slope, etc. Because of the long feeding distance of the dynamic trainload, power quality problems such as voltage drop, voltage imbalance and harmonic distortion my also occur to AC electrical railroad system. These problems affect not only power system stability, but also power quality deterioration in AC electrical railroad system. The dynamic simulation model of AC electrical railroad system presented by PSCAD/EMTDC is modeled in this paper, andthen, it is analyzed voltage drop for AC electrical railroad system both with single-phase distributed STATCOM(Static Synchronous Compensator) installed at SP(Sectioning Post) and without.

• 전기의세계
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• v.67 no.7
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• pp.30-33
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• 2018

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.79-80
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• 2013

MMC(Modular Multilevel Converter)는 여러 개의 Power Module을 직렬로 연결하여 정현파에 가까운 고전압의 파형을 얻을 수 있는 토폴로지로 대용량 전력변환 분야의 요구를 만족하면서 전력 품질을 향상시킬 수 있어 근래에 상당히 주목받고 있다. 당사에서는 5Mvar급 STATCOM(STATic synchronous COMpensator)을 MMC 형태로 제작하였다. 제작된 5Mvar급 STATCOM은 한 상당 12대의 Power Module로 구성하여 25-Level로 제작되었다. 제어시스템은 DSP(Digital Signal Processor)를 이용하였으며, 하나의 Main Controller와 다수의 Cell Controller, FPGA 보드 등으로 구성되어 있다. Controller 간의 상호 정보를 교환하기 위해 CAN 통신을 이용하였고, Power Module의 스위칭을 위한 보드는 각각에 연결되어 있으며, Cell Controller보드와는 절연을 위해 광신호로 연결하였다. 본 논문에서는 MMC 시스템의 제어기간 CAN 통신인터페이스와 Power Module의 PWM 동기화에 대해 설명을 하였다.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.181-183
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• 2008

This paper suggests local voltage control method to achieve coordinative control between STATCOM and other reactive power resources, such as Shunt Capacitor/Reactors and OLTC. Voltage/Reactive power control has various difficult aspects to control because of analysis and system dynamics error. This control method suggests practical algorithm regarding system voltage and reactive power status which is easy to implement in substation basis. In normal status, STATCOM-Shunts-OOTC are in operation. In emergency status, OLTC is locked. This algorithm is tested and verified in EMTDC.

• Proceedings of the KIEE Conference
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• 2001.05a
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• pp.262-265
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• 2001

최근 전력계통의 과부하, 전압안정도 등의 문제에 대한 해결책으로 FACTS (Flexible AC Transmission Systems)가 대두되고 있다. FACTS 설비에는 TCSC (Thyristor-Controlled Series Capacitor), SSSC (Static Synchronous Series Capacitor)와 같은 직렬 기기와 SVC(Static Var Compensator), STATCOM(STATic COMpensator) 와 같은 병렬기기 그리고, 본 논문에서 다루는 UPFC와 같은 직 병렬기기로 나누어진다. UPFC는 SSSC와 STATCOM을 결합한 형태로 유 무효전력을 동시에 보상할 수 있는 FACTS 기기이다. 본 논문에서는 한전 계통의 전압안정도 향상과 과부하 해소를 위해 강진S/S에 설치예정인 80MVA UPFC의 하드웨어 특성과 주변계통의 특성을 소개하고, UPFC와 한전 계통의 연계방안과 시험방안을 설명한다.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.115-116
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• 2008

This paper discusses local reactive power control method of substation which has FACTS controller(STATCOM) and other reactive power controllers. Not only The relation between entral control and local control method was discussed, but also local STATCOM control methd was done. With this results, revised coordinative control method which can implement system voltage sensitivity characteristics of each control devices. Also, this method can give proper solution for system status which requires momentary reactive reserve. This method is expected to be applied to control multiple substation reactive power devices which is combined with SCADA system.

• International Journal of Control, Automation, and Systems
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• v.6 no.4
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• pp.495-505
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• 2008

This paper describes modeling Voltage Sourced Inverter (VSI) type Flexible AC Transmission System (FACTS) controllers and control methods for power system dynamic stability studies. The considered FACTS controllers are the Static Compensator (STATCOM), the Static Synchronous Series Compensator (SSSC), and the Unified Power Flow Controller (UPFC). In this paper, these FACTS controllers are derived in the current injection model, and it is applied to the linear and nonlinear analysis algorithm for power system dynamics studies. The parameters of the FACTS controllers are set to damp the inter-area oscillations, and the supplementary damping controllers and its control schemes are proposed to increase damping abilities of the FACTS controllers. For these works, the linear analysis for each FACTS controller with or without damping controller is executed, and the dynamic characteristics of each FACTS controller are analyzed. The results are verified by the nonlinear analysis using the time-domain simulation.

• 전기의세계
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• v.53 no.7
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• pp.31-35
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• 2004

본 고에서는 현재 개발 및 필드테스트되고 있는 전력품질 보상기기인 STATCOM(Static Compensator), DVR(Dynamic Voltage Restorer), 고속전력절체스위치 SSTS(Solid State Transfer Switch)들이 국내 22.9kV급 배전계통에 도입되어 운용될 경우, 배전계통의 전력품질상의 외란, 즉 voltage sag, voltage swell, interruption등에 대해서도 부하기기가 문제없이 잘 동작할 수 있어야 하는 전력품질향상기기의 성능(전력품질향상기준)에 대한 평가방법 에 대하여 기술하고자 한다. 먼저, 전력품질향상기기인 DVR, D-STATCOM, SSTS들이 만족해야할 전력품질향상기준을 국내 전력 품질 실태를 고려하여 제시하고, 또한, 이들 전력품질향상기기에 대한 국내 배전계통적용에 적합한 성능평가방안을 제안/소개하기로 한다. (중략)

• Wind and Structures
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• v.22 no.6
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• pp.635-662
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• 2016

This paper deals with the comparison of different control strategies for the Induction generators in wind energy conversion system. Mainly, two types of induction machines, Self excited induction generator (SEIG) and doubly Fed Induction generators (DFIG) are studied. The different control strategies for SEIG and DFIG are compared. For SEIG, Electronic load Controller mechanism, Static Compensator based voltage regulator are studied. For DFIG the main control strategy namely vector control, direct torque control and direct power control are implemented. Apart from these control strategies for both SEIG and DFIG to improve the performance, the ANFIS based controller is introduced in both STATCOM and DTC methods. These control methods are simulated using MATLAB/SIMULINK and performances are analyzed and compared.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.11
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• pp.1929-1935
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• 2010

This paper describes the operation effect of FACTS devices in the Korean power system. At the year of 2010, three FACTS devices is under commercial operation in the Seoul area. Among them, 345kV ${\pm}100MVA$ STATCOM at Mi-Geum substation and 345kV ${\pm}200MVA$ SVC at Dong-Seoul substation are very close at their electrical and geographical distance. Therefore, the additional analysis including interaction and mutual transient is necessary. Therefore, a detailed EMTDC/PSCAD simulation model was developed and steady-state/transient analysis was implemented.