• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.2
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• pp.220-225
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• 2010

This paper deals with the robust stability analysis of STATCOM (Static Synchronous Compensator) power system for power quality enhancement and power system stability. The STATCOM plays an important role in controlling the reactive power flow to the power network and hence the system voltage fluctuations and stability. The control areas of this plant are very large and the overall composition of the system is nonlinear. Also, STATCOM is influence of the uncertainties so that it is necessary to apply the new control technique. For solving these problems, we perform the fuzzy modeling and robust analysis for STATCOM system.

• Journal of Power Electronics
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• v.10 no.5
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• pp.572-578
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• 2010

This paper discusses a transformerless shunt static compensator (STATCOM) based on a modular multilevel converter (MMC). It introduces a new time-discrete appropriate current control algorithm and a phase-shifted carrier modulation strategy for fast compensation of the reactive power and harmonics, and also for the balancing of the three-phase source side currents. Analytical formulas are derived to demonstrate the accurate mechanism of the stored energy balancing inside the MMC. Various simulated waveforms verify that the MMC based STATCOM is capable of reactive power compensation, harmonic cancellation, and simultaneous load balancing, while controlling and balancing all of the DC mean voltages even during the transient states.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.365-366
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• 2008

한전 전력연구원이 주관하고 (주)효성이 참여하는 협동연구과제로 100MVA STATCOM(Static Compensator)개발이 수행 중에 있다. 100MVA STATCOM의 반도체 스위칭 소자로는 IGCT(Integrated Gate Commutated Thyristor)를 사용하고 있다. 본 논문에서는 IGCT GDU(Gate Drive Unit)전원공급장치인 HFI(High Frequency Inverter) 설계에 대하여 기술하고 있다.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.367-368
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• 2008

한전 전력연구원이 주관하고 (주)효성이 참여하는 협동연구과제로 100MVA STATCOM(Static Compensator)개발이 수행 중에 있다. 100MVA STATCOM의 반도체 스위칭 소자로는 IGCT(Integrated Gate Commutated Thyristor)를 사용하고 있으며 IGCT GDU(Gate Deive Unit)의 전원공급용으로 HFI(High Frequency Inverter)를 사용한다. 본 논문에서는 설계 및 제작된 HFI를 실제 인버터 IGCT GDU전원 공급용으로 적용하여 확인한 성능에 대하여 기술하고 있다.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.146-148
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• 2001

The STATCOM(Static Compensator) resulted from the FACTS technology can generate or absorb reactive power rapidly so as to increase the transient stability and voltage stability. In this paper, effects of application of the STATCOM to the power system are analyzed from a viewpoint of improving voltage stability. The voltage stability is analyzed by use of repeated power flow method. The IPLAN, which is a high level language used with PSS/E program, is employed for evaluating the voltage stability.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.5
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• pp.422-428
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• 2013

Recently, we use a static synchronous compensator(STATCOM) with cascaded H-bride topologies, because it is easy to increase capacity and to reduce total harmonic distortion(THD). When we use equipment for reactive power compensation, dc-link voltage unbalances occur from several reasons although loads are balanced. In the past, switching pattern change of single phase inverter and reference voltage magnitude change of inverter equipped with power sensor have been used for dc-link voltage balance. But previous methods are more complicated and expensive because of additional component costs. Therefore, this paper explains reasons of dc-link voltage unbalance and proposes solution. This solution is complex method that is composed of reference voltage magnitude change of inverter without additional hardware and shifted phase angle of inverter reference voltages change. It proves possibility through 1000[KVA] system simulation.

• Journal of Electrical Engineering and Technology
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• v.11 no.5
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• pp.1057-1062
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• 2016

• Journal of Power Electronics
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• v.18 no.3
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• pp.944-953
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• 2018

This paper proposes an analysis method based on the magnitude-phase dynamic theory for isolated power systems with static synchronous compensators (STATCOMs). The stability margin of an isolated power system is greatly reduced when a load is connected, due to the disadvantageous features of the self-excited induction generators (SEIGs). To analyze the control process for system stability and to grasp the dynamic characteristics in different timescales, the relationships between the active/reactive components and the phase/magnitude of the STATCOM output voltage are derived in the natural reference frame based on the magnitude/phase dynamic theory. Then STATCOM equivalent mechanical models in both the voltage time scale and the current time scale are built. The proportional coefficients and the integral coefficients of the control process are converted into damping coefficients, inertia coefficients and stiffness coefficients so that analyzing its controls, dynamic response characteristics as well as impacts on the system operations are easier. The effectiveness of the proposed analysis method is verified by simulation and experimental results.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.9
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• pp.422-430
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• 2005

This paper describes experimental analysis of UPFC, which is composed of cascaded H-bridge modules and single-phase multi-winding transformers for isolation. The operational characteristic was analyzed through experimental works with a scaled model, and simulation results with PSCAD/EMTDC. The UPFC proposed in this paper can be directly connected to the transmission line without series injection transformers. It has flexibility to expand the operation voltage by increasing the number of H-bridge modules. The analysis results can be utilized to design the actual WFC system applicable for the transmission system.

• Journal of Electrical Engineering and Technology
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• v.7 no.5
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• pp.689-697
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• 2012

This paper proposes a new coordinated voltage control scheme between STATCOM (Static Synchronous Compensator) and reactive power compensation devices, such as shunt elements(shunt capacitor and shunt reactor) and ULTC(Under-Load Tap Changer) transformer in a local substation. If STATCOM and reactive power compensators are cooperatively used with well designed control algorithm, the target of the voltage control can be achieved in a suddenly changed power system. Also, keeping reactive power reserve in a STATCOM during steady-state operation is always needed to provide reactive power requirements during emergencies. This paper describes the coordinative voltage control method to keep or control the voltage of power system in an allowable range of steady-state and securing method of momentary reactive power reserve using PSS/E with Python. In the proposed method of this paper, the voltage reference of STATCOM is adjusted to keep the voltage of the most sensitive bus to the change of loads and other reactive power compensators also are settled to supply the reactive power shortage in out range of STATCOM to cope with the change of loads. As the result of simulation, it is possible to keep the load bus voltage in limited range and secure the momentary reactive power reserve in spite of broad load range condition.