• Title/Summary/Keyword: Micro Grid System

Search Result 181, Processing Time 0.036 seconds

A Study on the Stability of Micro-Grid System (마이크로그리드 시스템의 안정도에 관한 기초 연구)

  • Son, Kwong-Myoung;Lee, Kye-Byung
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.21 no.7
    • /
    • pp.46-53
    • /
    • 2007
  • Micro-grid consists of micro-sources which adopt environmentally friendly and reliable power sources such as Fuel-Cell and Micro-Turbines with independent real and reactive power control capability for providing premium power quality. This paper deals with the basic aspect of dynamic modeling and the stability analysis of the micro-grid system. The fundamental frequency model of the micro-source inverters are considered to form a dynamic model of the micro-grid system Stability analysis is performed based on the linearized dynamic model of the micro-grid system Case study results show the parameters affecting the stability of the micro-grid.

A Study on the Stability of Micro-Grid System Considering Operating Range of Micro-Sources (Micro-Source의 운전 범위에 따른 Micro-Grid 시스템 의 안정도에 관한 연구)

  • Son, Kwang M.;Lee, Kye B.
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.56 no.5
    • /
    • pp.841-847
    • /
    • 2007
  • This paper deals with the micro-grid consisting of micro-sources which adopt voltage sourced inverters with independent real and reactive power control capability for providing premium power quality. This paper presents dynamic modeling and the stable operating range of the micro-grid system varying the parameters of the micro-sources. The fundamental frequency model of the micro-source inverters are considered to form a dynamic model of the micro-grid system. Stability analysis is performed based on the linearized dynamic model of the micro-grid system. Case study results show the parameters affecting the stability of the micro-grid and the stable operating range of the micro-sources.

A Study on the Dynamic Analysis of Micro-Grid System (Micro-Grid 시스템의 동특성 해석에 관한 기초 연구)

  • Son, Kwang-M.;Lee, Kye-B.;Jeon, In-Soo
    • Proceedings of the KIEE Conference
    • /
    • 2007.07a
    • /
    • pp.543-544
    • /
    • 2007
  • Micro-grid consists of micro-sources which adopt environmentally friendly and reliable power sources with independent real and reactive power control capability for providing premium power quality. This paper presents dynamic modeling and the stable operating range of the micro-grid system varying the parameters of the micro-sources. Case study results show the parameters affecting the stability of the micro-grid and the stable operating range of the micro-sources.

  • PDF

Micro-Grid System Analysis (마이크로그리드 시스템 해석)

  • Son, Kwang-M.;Lee, Kye-B.
    • Proceedings of the KIEE Conference
    • /
    • 2005.07a
    • /
    • pp.280-282
    • /
    • 2005
  • Micro-source units having power ratings in thousands of watts can provide even higher reliability and fuel efficiency than the conventional large scale units. These units are also clustered with loads creating micro-grid services to customer sites such as office buildings, industrial parks and homes. Micro-sources adopt voltage source inverter to ensure the power quality of sensitive loads. This paper deals with the connection of micro-sources into the system grid. Modeling and simulation of the grid connected micro-sources at the power frequency range are investigated. Simulation results show that the micro-grid system with two micro-sources has good dynamic characteristics.

  • PDF

Stability Enhancement of a Hybrid Micro-grid System in Grid Fault Condition

  • Ambia, Mir Nahidul;Al-Durra, Ahmed;Caruana, Cedric;Muyeen, S.M.
    • Journal of international Conference on Electrical Machines and Systems
    • /
    • v.2 no.2
    • /
    • pp.225-231
    • /
    • 2013
  • Low voltage ride through capability augmentation of a hybrid micro-grid system is presented in this paper which reflects enhanced reliability in the system. The control scheme involves parallel connected multiple ac-dc bidirectional converters. When the micro-grid system is subjected to a severe voltage dip by any transient fault single power converter may not be able to provide necessary reactive power to overcome the severe voltage dip. This paper discusses the control strategy of additional power converter connected in parallel with main converter to support extra reactive power to withstand the severe voltage dip. During transient fault, when the terminal voltage crosses 90% of its pre-fault value, additional converter comes into operation. With the help of additional power converter, the micro-grid system withstands the severe voltage fulfilling the grid code requirements. This multiple converter scheme provides the micro-grid system the capability of low voltage ride through which makes the system more reliable and stable.

An Operation and Control Algorithm of Micro-grid (차세대전력공급네트워크(Micro-grid)의 운용제어앨고리즘)

  • Rho, Dae-Seok;Kim, Jae-Eon
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.8 no.2
    • /
    • pp.232-239
    • /
    • 2007
  • There is an increasing concern to interconnect DG(Distributed Generation) units into a distribution system and operate and maintain the system power quality within a proper level to distribution companies, regional electricity utilities and industrial customers. Recently, this situation makes many experts estimate a next generation of distribution system which is composed of some micro-grids. But the proposed micro-grid is only mentioned as a small grid with some DG units, some power quality compensators, communication and control equipments. In this paper, a topology and an operation/control algorithm of the micro-grid which is able to supply the electricity with high reliability and quality, are proposed.

  • PDF

Static Switch Controller Based on Artificial Neural Network in Micro-Grid Systems

  • Saeedimoghadam, Mojtaba;Moazzami, Majid;Nabavi, Seyed. M.H.;Dehghani, Majid
    • Journal of Electrical Engineering and Technology
    • /
    • v.9 no.6
    • /
    • pp.1822-1831
    • /
    • 2014
  • Micro-grid is connected to the main power grid through a static switch. One of the critical issues in micro-grids is protection which must disconnect the micro-grid from the network in short-circuit contingencies. Protective methods of micro-grid mainly follow the model of distribution system protection. This protection scheme suffers from improper operation due to the presence of single-phase loads, imbalance of three-phase loads and occurrence of power swings in micro-grid. In this paper, a new method which prevents from improper performance of static micro-grid protection is proposed. This method works based on artificial neural network (ANN) and able to differentiate short circuit from power swings by measuring impedance and the rate of impedance variations in PCC bus. This new technique provides a protective system with higher reliability.

A Study on the Modeling and Analysis of the Micro-Grid (마이크로그리드의 모델링 및 해석에 관한 기초 연구)

  • Son, Kwang-M.;Lee, Kye-B.
    • Proceedings of the KIEE Conference
    • /
    • 2006.07a
    • /
    • pp.533-534
    • /
    • 2006
  • Micro-source units having power ratings in thousands of watts can provide power quality with higher reliability and efficiency than the conventional large scale units. This paper develops switching level model of micro-source and studies the characteristics of the micro-grid consisting of multiple micro-sources and interfaced with electric power system. The developed model adopts the space vector PWM to fully utilize the capacity of inverter. The interaction of the grid connected micro-sources and the characteristics of the control system parameters are investigated. Micro-sources and micro-grid are implemented using PSCAD/EMTDC. Simulation results show that the proposed model is efficient for studying micro-grid system.

  • PDF

Optimal Operation Scheme and Reliability Index Improvement of Micro Grid Using Energy Storage Systems (에너지 저장장치를 이용한 마이크로 그리드의 최적운영 및 신뢰도 지수 개선)

  • Kim, Kyu-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.63 no.2
    • /
    • pp.205-210
    • /
    • 2014
  • The micro grid considered in this paper consists of a diesel generator, a photovoltaic array, a wind turbine, a fuel cell, and a energy storage system. This paper explains and simulates the micro grid components in terms of accuracy and efficiency of having a system model based on the costs of fuel as well as operation and maintenance. For operational efficiency, the objective function in a diesel generator consists of the fuel cost function similar to the cost functions used for the conventional fossil-fuel generating plants. The wind turbine generator is modeled by the characteristics of variable output. The optimization is aimed at minimizing the cost function of the system while constraining it to meet the customer demand and safety of micro grid. The operating cost in fuel-cell system includes the fuel costs and the efficiency for fuel to generate electric power. To develop the overall system model gives a possibility to minimize of the total cost of micro grid. The application of optimal operation can save the interruption costs as well as the operating costs, and improve reliability index in micro grid.

Modeling and Analysis of the Micro-Grid with SVPWM Micro-Sources (SVPWM 방식 마이크로소스로 구성된 마이크로그리드 모델링 및 해석)

  • Son, Kwang-Myung;Lee, Kye-Byung;Kim, Young-Seob
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.20 no.3
    • /
    • pp.12-19
    • /
    • 2006
  • Micro-source units having power ratings in thousands of watts can provide power quality with higher reliability and efficiency than the conventional large scale units. This paper develops switching level model of micro-source and studies the characteristics of the micro-grid consisting of multiple micro-sources and interfaced with electric power system. The developed model adopts the space vector PWM to fully utilize the capacity of inverter. The interaction of the grid connected micro-sources and the characteristics of the control system parameters are investigated. Micro-sources and micro-grid are implemented using PSCAD/EMTDC. Simulation results show that the proposed model is efficient for studying micro-grid system.