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MICROGRIDS AND DISTRIBUTED GENERATION SYSTEMS: CONTROL, OPERATION,COORDINATION AND PLANNING
Title
MICROGRIDS AND DISTRIBUTED GENERATION SYSTEMS: CONTROL, OPERATION,COORDINATION AND PLANNING
Creator
Che, Liang
Date
2015, 2015-07
Description
Distributed Energy Resources (DERs) which include distributed generations (DGs), distributed energy storage systems, and adjustable loads are...
Show moreDistributed Energy Resources (DERs) which include distributed generations (DGs), distributed energy storage systems, and adjustable loads are key components in microgrid operations. A microgrid is a small electric power system integrated with onsite DERs to serve all or some portion of the local loads and connected to the utility grid through the point of common coupling (PCC). Microgrids can operate in both gridconnected mode and island mode. The structure and components of hierarchical control for a microgrid at Illinois Institute of Technology (IIT) are discussed and analyzed. Case studies would address the reliable and economic operation of IIT microgrid. The simulation results of IIT microgrid operation demonstrate that the hierarchical control and the coordination strategy of distributed energy resources (DERs) is an effective way of optimizing the economic operation and the reliability of microgrids. The benefits and challenges of DC microgrids are addressed with a DC model for the IIT microgrid. We presented the hierarchical control strategy including the primary, secondary, and tertiary controls for economic operation and the resilience of a DC microgrid. The simulation results verify that the proposed coordinated strategy is an effective way of ensuring the resilient response of DC microgrids to emergencies and optimizing their economic operation at steady state. The concept and prototype of a community (networked) microgrid that interconnecting multiple microgrids in a community are proposed. Two works are conducted. For the coordination, novel three-level hierarchical coordination strategy to coordinate the optimal power exchanges among neighboring microgrids is proposed. For the planning, a multi-microgrid interconnection planning framework using probabilistic minimal cut-set (MCS) based iterative methodology is proposed for enhancing the economic, resilience, and reliability signals in multi-microgrid operations. The implementation of high-reliability microgrids requires proper protection schemes that effectively function in both grid-connected and island modes. This chapter presents a communication-assisted four-level hierarchical protection strategy for highreliability microgrids, and tests the proposed protection strategy based on a loop structured microgrid. The simulation results demonstrate the proposed strategy to be an effective and efficient option for microgrid protection. Additionally, microgrid topology ought to be optimally planned. To address the microgrid topology planning, a graph-partitioning and integer-programming integrated methodology is proposed. This work is not included in the dissertation. Interested readers can refer to our related publication.
Ph.D. in Electrical and Computer Engineering, July 2015
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MICROGRID OPERATION, CONTROL AND PROTECTION AT lIT
Title
MICROGRID OPERATION, CONTROL AND PROTECTION AT lIT
Creator
Che, Liang
Date
2013, 2013-07
Description
Distributed Energy Resource (DER) which includes distributed generation (DG), distributed storage system, and adjustable loads is a key...
Show moreDistributed Energy Resource (DER) which includes distributed generation (DG), distributed storage system, and adjustable loads is a key component in microgrid operations. Microgrids could be clustered at distribution levels to enhance the economics and the reliability of small DGs such as microturbines and wind generation turbines as well as DGs with power electronic interfaces such as photovoltaic (PV) arrays and fuel cells. Microgrid is a small electric power system integrated with on-site DERs to serve all or some portion of the local load which is connected to the utility grid through the point of common coupling (PCC). Microgrids can operate in both grid-connected mode and island mode. The structure and components of hierarchical control for a microgrid at Illinois Institute of Technology (IIT) are discussed and analyzed. Case studies would address the reliable and economic operation of IIT microgrid. The simulation results of IIT microgrid operation demonstrate that the hierarchical control and the coordination strategy of distributed energy resources (DERs) is an effective way of optimizing the economic operation and the reliability of microgrids. The protection is one of the crucial challenges of microgrid operation. Traditional protection schemes for radial distribution networks will not work successfully in microgrids without much modification. The protection scheme of IIT microgrid is discussed. Based on the fault current contributed by synchronous generators in island mode, the IIT microgrid adopts a localized differential protection scheme with adaptive xiv relay settings which feature a multi-level backup protection strategy. The proposed protection scheme would utilize the looped structure of IIT microgrid for enhancing the reliability of microgrid operation. The simulation results of IIT microgrid protection show the effectiveness of the proposed protection scheme.
M.S. in Electrical Engineering, July 2013
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