• Proceedings of the KIPE Conference
• /
• 2014.07a
• /
• pp.548-549
• /
• 2014

In Jeju power sytstem, the generation of reactive power depends on the operation of CSC-HVDC filter. Thus, the grid voltage will be affected. Statcom and SVC have demonstrated that it has excellent charateristics to solve this problem. First, this paper analyzes the operation of the Statcom based on the real power system in Jeju. Then, the characteristics of Statcom will be compared to the SVC. The modelling of the Jeju power system including Statcom and SVC will be performed by using PSCAD/EMTDC program and the real data from the real Jeju power system.

• Proceedings of the KIPE Conference
• /
• 2012.07a
• /
• pp.240-241
• /
• 2012

본 연구에서는 분산전원과 에너지저장으로 구성된 독립형 DC 마이크로그리드의 신뢰도를 향상시키기 위한 협조적 Droop 제어기법을 제안하고 그 성능과 동작을 분석한 내용에 대해 기술하고 있다. 제안하는 시스템의 동작 타당성을 체계적으로 분석하기 위해 PSCAD/EMTDC 소프트웨어를 이용한 시뮬레이션 모델을 개발하였으며 이를 기반으로 하드웨어 시스템을 제작하여 제안하는 시스템의 동작특성을 분석하였다.

• Proceedings of the KIPE Conference
• /
• 2015.07a
• /
• pp.291-292
• /
• 2015

본 논문은 계통과 연계된 3상 전압원 인버터를 기반으로 한 BESS의 능동 단독 운전 검출 방법을 제안한다. 계통 전압의 불평형에서도 안정적으로 위상을 추종할 수 있는 DDSRF_PLL(Decoupled Double Synchronous Reference Frame_PLL)방식을 적용 하였으며, 검출된 위상각 정보를 통해 정상분 전류 제어기와 역상분 전류 제어기를 독립적으로 제어할 수 있게 된다. 이를 위해 IEEE 1547과 UL1741에서 제시하는 단독 운전 기준 시험 회로를 구성하여 PSCAD/EMTDC 소프트웨어를 통한 시뮬레이션과 5kw프로토타입 하드웨어 장치를 통해 제안된 단독 운전 검출 방법을 검증하였다.

• Proceedings of the KIPE Conference
• /
• 2015.07a
• /
• pp.115-116
• /
• 2015

본 논문에서는 PSCAD/EMTDC 소프트웨어를 이용하여 3MVA 용량의 풍력발전기와 2.4MVA 용량의 파력발전기로 구성되어 있는 부유식 파력-해상풍력 연계형 발전시스템 모델을 모의 할 예정이다. 각각의 발전시스템은 발전기, 발전기 컨버터, 전력망 컨버터, 전력망으로 구성되어 있고 시뮬레이션 결과를 통해 각각의 풍력 및 파력발전기에서 전력망의 유효전력과 무효전력을 완전히 독립적으로 제어 할 수 있음에 대하여 살펴 볼 것이다.

• Proceedings of the KIPE Conference
• /
• 2015.07a
• /
• pp.371-372
• /
• 2015

Dc microgrid has the advantage of high efficiency as compared to the ac system. Droop method has been realized to suppress the current mismatching among the distributed sources. However, this method involves distribution loss due to the line impedance. In this paper, a novel droop method is proposed to minimize the distribution loss as well as the voltage deviation by adjusting the droop coefficient. The proposed droop method is verified by using the simulation based on PSCAD/EMTDC.

• Proceedings of the KIPE Conference
• /
• 2012.07a
• /
• pp.351-352
• /
• 2012

본 논문에서는 최근 직류송전용 컨버터로 많은 관심이 집중되고 있는 MMC(Modular Multi-level Converter)에 대해서 소개하고 있다. 대용량 전압원 컨버터로 MMC가 적합한 이유에 대해서 설명하고, MMC의 동작원리, SM(Sub-Module) dc capacitor voltage balancing 기술, 전체 제어 시스템에 대해 자세하게 설명하고 있다. 제안하는 MMC는 Staircase Modulation 방식으로 사인파형에 가까운 출력전압을 형성하고, Sorting 알고리즘을 구현하여 개별 SM의 커패시터 전압이 균등하게 일정 값을 유지하도록 하였다. 제안하는 MMC의 성능평가를 위하여 PSCAD/EMTDC 프로그램을 이용하여 3상 11-level MMC를 모의하였다.

• Proceedings of the KIEE Conference
• /
• 2004.11b
• /
• pp.24-27
• /
• 2004

This paper proposes a new algorithm of underground cable fault location based on the analysis of distributed parameter circuit. The proposed method firstly makes voltage and current equations for each of cores and sheathes respectively, and then establishes an equation of the fault distance according to the analysis of the fault conditions. Finally the solution of this equation is calculated by Newton-Raphson iteration method. The effectiveness of this proposed algorithm has been proven through PSCAD/EMTDC simulations.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.4
• /
• pp.733-738
• /
• 2011

As increase of nonlinear loads and renewable energy generators (REGs) being connected to power distribution system via inverters, the concern on harmonic problems have increased. Recently, the harmonics evaluation method considering TDD (Total Demand Distortion) is used to analyze the effect of harmonics from inverters on power distribution quality. Harmonic current sources are typically used for simulation of nonlinear load. Most inverter type for REGs is voltage source inverter (VSI). So, harmonic voltage sources are more suitable to analyze impact of renewable energy generator on harmonics problem in power distribution system. In this paper, we presented the circuit model to analyze interaction between harmonics from nonlinear load and REGs. We verified that the harmonic analysis using the proposed circuit model is more appropriate than the harmonics evaluation method considering TDD through case study using PSCAD/EMTDC.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.61 no.7
• /
• pp.966-973
• /
• 2012

In microgrid demonstration site, distributed generations can make bidirectional power flows on the system. If an accident occurs, the fault current from the inverter based distributed generation is small. However, the conventional protection scheme in distribution network is designed to operate at high fault current. This means that the traditional protection of distribution network is no longer applicable and new protection methods must be developed. In this paper, for two cases, algorithms for protection coordination of demonstration site is proposed and verified through PSCAD/EMTDC simulation. In first case, protection devices are assumed to have the abilities of directional relaying and communication. In second case, protection devices do not have those abilities. Proposed protection coordination algorithms detect the fault locations and protect the microgrid fairly well.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.61 no.1
• /
• pp.41-49
• /
• 2012

This paper describes the operation mode development for the grid-tied PMSG(permanent magnet synchronous generator) wind power system combined with a battery energy storage. The development of operation modes was carried out through simulations with PSCAD/EMTDC software and experiments with a 10kW hardware prototype. The detailed simulation models for PMSG wind power system and battery energy storage were developed using user-defined models programed with C-code. A 10kW hardware simulator was built and tested in connection with the local load and the utility power. The simulation and experimental results confirm that the grid-tied PMSG wind power system combined with battery energy storage can supply highly reliable power to the local load in various operation modes.