• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.456_457
• /
• 2009

본 논문은 마이크로소스를 계통 연계하여 운전 시 필수적이므로 계통연계시의 기술적인 과제인 분산전원 종류에 의한 전압 고조파 및 주파수 안정도를 풍력발전의 회전자와 연료전지의 인버터에 연결 하였을 경우 미치는 영향과 저압 연료전지와 특 고압 풍력발전의 특성을 simulink를 사용하여 시뮬레이션을 구현하며 부하에 미치는 영향에 대하여 알아보도록 한다.

• Proceedings of the KIPE Conference
• /
• 2016.11a
• /
• pp.196-197
• /
• 2016

신재생 에너지와 배터리를 이용하여 소규모로 계통을 구축하여 부하에 전기를 공급하는 시스템을 Microgrid라 한다. 태양광 모듈과 배터리의 성능 향상 및 가격 경쟁력 강화로 인하여, Microgrid는 오지에 전기를 공급하거나 기존 디젤 발전시설을 대체하거나 운영 비용을 감소하는 용도로 각광 받고 있다. 본 논문에서는 디젤 발전기와 강에서 유체동력 발전기로 전기를 공급하는 시스템에 태양광과 배터리를 설치하여 기존 발전 비용을 최소화 하면서 최단 시간내에 투자 비용을 회수할 수 있는 솔루션을 제안한다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2012.04a
• /
• pp.892-893
• /
• 2012

마이크로그리드 (microgrid)의 성능을 최적화하기 위해서는 마이크로그리드를 구성하는 분산 시스템간 협력적인 제어 기능이 요구된다. 멀티 에이전트 (multi-agent) 시스템은 이러한 마이크로그리드의 분산 제어를 위한 해결책 중 하나이다. 본 논문에서는 중앙 집중방식 멀티에이전트 시스템을 기반으로 마이크로그리드의 효율적인 제어를 위한 시스템을 설계하였다.

• Proceedings of the KIPE Conference
• /
• 2019.07a
• /
• pp.483-484
• /
• 2019

This paper proposes a harmonic state space (HSS) modeling of DC microgrid. In the HSS model, nonlinear equations for the switched circuit model are transformed into multiple linear equations. The simulation results have shown the HSS modeling is comparable with PSIM simulation.

• 열병합발전
• /
• s.68
• /
• pp.18-23
• /
• 2009

• 열병합발전
• /
• s.66
• /
• pp.19-25
• /
• 2008

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.9
• /
• pp.6419-6424
• /
• 2015

Recently, high-cost energy storage systems are applying to hybrid generation systems with wind turbine and diesel generator in island areas for stable operation. But, this paper proposes an operating algorithm and modeling method of an islanding microgrid that is composed of PMSG(Permanent Magnet Synchronous Generator) and Diesel Generator applied in island areas without such energy storage system. Initially, the operating algorithm was proposed for frequency and voltage to be maintained within the proper ranges for the load and weather change. And then the modeling method were proposed for PMSG, WT-side AC/DC converter and Grid-side DC/AC converter. The proposed operating algorithm and modeling method were applied to a typical islanded microgrid with PMSG wind turbine and diesel generator. The frequency and voltage was kept within the permissible ranges and the proposed method was proven to be appropriate through simulations.

• Journal of Power Electronics
• /
• v.18 no.1
• /
• pp.234-250
• /
• 2018

This paper presents a new load sharing control for use between paralleled three-phase inverters in an islanded microgrid based on the online line impedance estimation by the use of a Kalman filter. In this study, the mismatch of power sharing when the line impedance changes due to temperature, frequency, significant differences in line parameters and the requirements of the Plug-and-Play mode for inverters connected to a microgrid has been solved. In addition, this paper also presents a new droop control method working with the line impedance that is different from the traditional droop algorithm when the line impedance is assumed to be pure resistance or pure inductance. In this paper, the line impedance estimation for parallel inverters uses the minimum square method combined with a Kalman filter. In addition, the secondary control loops are designed to restore the voltage amplitude and frequency of a microgrid by using a combined nominal value SOGI-PLL with a generalized integral block and phase lock loop to monitor the exact voltage magnitude and frequency phase at the PCC. A control model has been simulated in Matlab/Simulink with three voltage source inverters connected in parallel for different ratios of power sharing. The simulation results demonstrate the accuracy of the proposed control method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.24 no.7
• /
• pp.20-25
• /
• 2010

With the diversification of distribution facilities, existing distributed generation can be subdivided into Microgrids, which are smaller units for application. These Microgrids, subdivided as such and connected to distribution systems, should operate under driving plans that will ensure their economic efficiency and, accordingly, the configuration of those distribution systems that include Microgrids should also be changed. The perception of the necessity to secure the economic efficiency of distribution systems is gradually increasing and studies intended to assess the economic efficiency of Microgrids and Smartgrids are ongoing. In this paper, the power generation capacity of an economically operative Microgrid was calculated using the MonteCarlo simulation, which is a method based on the probability theory considering the power generation cost of Microgrids linked with power supply systems and reverse sales costs, etc., and an optimum distribution systems was configured based on the results of these calculation.

• Journal of Power Electronics
• /
• v.15 no.3
• /
• pp.741-752
• /
• 2015

This study proposes a new solution for the parallel operation of microgrid inverters in terms of circuit topology and control structure. A combined three-phase four-wire inverter composed of three single-phase full-bridge circuits is adopted. Moreover, the control structure is based on adaptive three-order sliding-mode control and wireless load-sharing control. The significant contributions are as follows. 1) Adaptive sliding-mode control performance in inner voltage loop can effectively reject both voltage and load disturbances. 2) Virtual resistive-output-impedance loop is applied in intermediate loop to achieve excellent power-sharing accuracy, and load power can be shared proportionally to the power rating of the inverter when loads are unbalanced or nonlinear. 3) Transient droop terms are added to the conventional power outer loop to improve dynamic response and disturbance rejection performance. Finally, theoretical analysis and test results are presented to validate the effectiveness of the proposed control scheme.