• 전자공학회논문지
• /
• 제52권5호
• /
• pp.225-234
• /
• 2015

가상발전소(Virtual Power Plant)는 비상발전(DG), 열병합발전(CHP), 에너지 저장 장치(ESS), 부하(Load)등과 같은 분산 에너지 자원을 ICT기반의 기술로 연계하여 하나의 단일 발전소와 같이 운영하는 기술이다. 지금까지의 가상발전소는 하나의 가상발전 플랫폼을 통하여 광범위하게 산재해 있는 다양한 분산 에너지 자원을 네트워크로 연결하는 구조를 기반으로 개발되고 실증되었다. 그러나 분산 에너지 자원 종류 및 수가 지속적으로 증가할 경우 이러한 분산 에너지 자원과 관련된 데이터 또한 기하급수적으로 증가할 수밖에 없으며 분산 에너지 자원의 분포가 광범위한 지역에 분포되어 있는 경우 하나의 가상발전 플랫폼으로 이들 모든 자원에 대한 네트워크를 중앙 집중형으로 가져가는 것은 네트워크 구성을 위한 기술적, 비용적 측면에서 매우 비효율적이다. 따라서 본 논문에서는 광범위한 지역에 분포되어 있는 분산 에너지 자원을 효율적으로 관리함으로써 시스템 부하에 따른 오류 확률을 낮추고, 분산 에너지 자원과의 데이터 교환의 견고성과 가상발전소의 확장성을 확보할 수 있는 대단위 가상 발전소 구성 방법을 제안한다. 또한 대단위 가상 발전소 구성 시 분산 에너지 자원을 직접적으로 제어하고 모니터링하는 소단위 가상발전 플랫폼에서 가변 및 민감성 부하를 고려한 최적의 자원 스케줄링 방법 또한 시뮬레이션을 통해 그 결과의 유효성을 검증한다.

• 전기학회논문지
• /
• 제59권12호
• /
• pp.2157-2164
• /
• 2010

Microgrid is generally defined as cluster of small distributed generators, energy storages and loads. Through monitoring and coordinated control, microgrid can provide various benefits such as reduction of energy cost, peak shaving and power quality improvement. In design stage of microgrid, system dynamic simulation is necessary for optimizing of sizing and siting of DER(distributed energy resources). As number of the system components increases, simulation time will be longer. This problem can restrict optimal design. So we used simplified modeling on energy sources and average switching model on power converters to reduce simulation time. The effectiveness of this method is verified by applying to prototype microgrid system, which is consist of photovoltaic, wind power, diesel engine generators, battery energy storage system and loads installed in laboratory. Simulation by Matlab/Simulink and measurements on prototype microgrid show that the proposed method can reduce simulation time not sacrificing dynamic characteristics.

• 조명전기설비학회논문지
• /
• 제21권3호
• /
• pp.132-141
• /
• 2007

최근 경제 발전으로 인한 전력 에너지 소비 증가로 발전선비의 확충이 요구되는 상황이다. 그러나 화석연료고갈 및 지구환경문제로 대형 화력 발전설비의 확충이 어려워지고 있다. 따라서 발전부지 확보가 용이하고 환경오염의 위험이 적은 분산전원에 대한 관심이 한층 더 고조되고 있다. 그러나 이러한 분산전원이 배전계통에 연계되면 전압변동, 고조파, 보호협조, 고장전류 증가 등의 문제를 일으키므로 이에 대한 적절한 연구가 필요하다. 본 논문에서는 국내 22.9[kV] 배전계통에 다수의 분산전원이 연계되었을 경우, 각 계전기가 감지하는 고장전류의 크기와 방향성을 고려하여 고장 감지 및 고장 지점을 확인하는 방법을 제안하였다. 이를 기반으로 하여 배전계통 보호기기인 자동재폐로 차단기-구분개폐기 보호시스템이 상호협조를 이루기 위한 온라인 보호 협조방안을 제시하였다.

• 한국정보시스템학회지:정보시스템연구
• /
• 제27권2호
• /
• pp.95-114
• /
• 2018

Purpose The recent concern over environmental problems such as greenhouse gas emission and fine dust contributes increasing interest in renewable energies. However the intrinsic characteristics of renewable energies, intermittent and stochastic generation, might cause serious problems to the stability and controllability of power grid. Therefore countermeasures such as virtual power plant (VPP) must be prepared in advance of the spread of uncontrollable distributed renewable energy resources to be one of major energy sources. Design/methodology/approach This study deals with the design concept of the VPP platform. we proposed as a technology solution for achieving the stability of power grid by guaranteeing a single power profile combining multiple distributed power sources with ICT. The core characteristics of VPP should be able to participate in the grid operation by responding to operation instructions from the system operator, KPX, as well as the wholesale electricity market. Findings Therefore this study includes energy storage device(ESS) as a controllable component as well as renewable energy resources such as photovoltaic and wind power generation. Based on this configuration, we discussed core element technologies of VPP and protype design of VPP solution platform according to system requirements. In the proposed solution platform, UX design for the integrated control center and brokerage system were included as well as ancillary service function to respond to KPX's operation instruction with utilizing the capability of ESS. In addition, a simulator was suggested to verify the VPP operations.

• 전기학회논문지
• /
• 제65권2호
• /
• pp.239-246
• /
• 2016

In recent years, the power demand has been increasing steadily and the occurrence of maximum power demand has been moving from the summer season to the winter season in Korea. And since the control of electric power supply and demand is more important under those situations, a micro-grid system began to emerge as a keyword for the sTable operation of electric power system. A micro-gird power system is composed of various kinds of distributed generators(DG) such as small diesel generator, wind turbine, photo-voltaic generator and energy storage system(ESS). This paper introduces a method to determine the optimal capacities of the distributed generators which are installed in a stand-alone type of microgrid power system based on the fundamental proportion of diesel generator. At first, the fundamental proportion of diesel generator will be determined by changing from 0 to 50 percent. And then we will optimize the capacities of renewable energy resources and ESS according to load patterns. Lastly, after recalculating the capacity of ESS with consideration for SOC constraints, the optimal capacities of distributed generators will be decided.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
• /
• pp.429-431
• /
• 2005

According to the second plan of the Korean Government about technology development, utilization and popularization of new renewable energy, the continuous growth of distributed resources are expected. Various studies about impact of distributed resource on distribution system have been already accomplished. Rut there is a few paper about recloser and sectionalizer coordination and protection scheme in distribution system interconnected a number of distributed resources. In this paper, it is dealt with that recloser and sectionalizer coordination at the cases concerned with fault position. The problems of these cases are investigated through simulation.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2006년도 전력전자학술대회 논문집
• /
• pp.520-522
• /
• 2006

According to the second scheme of the Korean Government about technology development, utilization and popularization of new renewable energy, the continuous growth of distributed resources are expected. But there is a few paper about recloser and sectionalizer coordination and protection scheme in distribution system interconnected a number of distributed resources. In this paper, it is dealt with that recloser and sectionalizer coordination at the cases concerned with position among protection devices. Adding distributed resource, the problems of each case are investigated through simulation.

• Journal of international Conference on Electrical Machines and Systems
• /
• 제1권4호
• /
• pp.425-433
• /
• 2012

As the demand for electric power increases rapidly and the amount of fossil fuels decreases year by year, making use of renewable resources seem very necessary. However, due to the discontinuous nature of renewable resources and the hierarchical topology of existing grids, power quality and grid stability will deteriorate as more and more distributed generations (DGs) are connected to the grids. It is a good idea to combine local utilization, local consumption, energy storage and DGs to form a grid-friendly micro grid, these micro grids can then assembled into an intelligent power system - the smart Grid. It can optimize power flow and integrate power generation and consumption effectively. Most importantly, the power quality and grid stability can be improved greatly. This paper depicts how the smart grid addresses the current issues of a power system. It also figures out the key technologies and expectations of the smart grid.

• KEPCO Journal on Electric Power and Energy
• /
• 제2권4호
• /
• pp.569-575
• /
• 2016

In this paper, we propose a method to develop a static equivalent model of an inverter-based distributed energy resource (DER), where the model is used for a steady-state fault analysis of a power grid. First, we introduce the characteristics of an inverter-based DER as well as its general configuration. Then, we derive the equivalent model of the DER on the basis of the characteristics. Last, the performance of the proposed method is proven by the results of computer simulations.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2005년도 전력전자학술대회 논문집
• /
• pp.704-706
• /
• 2005

According to the second scheme of the Korean Government about technology development, utilization and popularization of new ${\cdot}$ renewable energy, the continuous growth of distributed resources are expected. But there is a few paper about recloser and sectionalizer coordination and protection scheme in distribution system interconnected a number of distributed resources. In this paper, it is dealt with that recloser and sectionalizer coordination at the cases concerned with position among protection devices. Adding distributed resource, the problems of each case are investigated through simulation.