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- Title
- MICROGRIDS AND DISTRIBUTED GENERATION SYSTEMS: CONTROL, OPERATION,COORDINATION AND PLANNING
- Creator
- Che, Liang
- Date
- 2015, 2015-07
- Description
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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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- Title
- Value of DER to distribution networks
- Creator
- Nasiri, Hiva
- Date
- 2019
- Description
-
Distributed energy resources (DERs) provide various values to electric power systems. One of the challenges DER introduce is to determine what...
Show moreDistributed energy resources (DERs) provide various values to electric power systems. One of the challenges DER introduce is to determine what is the value of DER contributions to various sectors in distributed power systems. Analyzing such challenges require understanding the inherent variability of DERs and the uncertainty in hourly load. The value of DER is also a function of network conditions and its adaptability for responding to DERs and loading variations.The uncertain conditions in the planning and the operation of electric power systems make the DER valuation a complicated task which requires sophisticated analytical methods. DER valuation will be a critical issue for the power market operation as we try to determine the most economical and reliable generation portfolio to maximize social welfare. In the DER valuation, there is a stage in which the DER candidates are not located or sized properly, and the utility will provide an approximated solution in order to value DERs. In this thesis, DER valuation has been addressed initially using a stochastic analysis in order to determine a range of values. Once the range is determined, we calculate the economic viability of the values within the range. If DER can reduce the upgrade cost for delivering the load in a distribution system, then the proposed size and the location of DER will have viability. In addition, with the proposed method, a utility can decide on the cost and the methodology of mitigating contingencies by DERs and allocate that cost to the amount of DER for valuation. This is considered as the second phase of this valuation method.As the final phase of this thesis, different types of financial contracts are considered as part of valuation which can introduce additional merits to the utility operation. Recently, the concept of real options has been considered in electric power system projects. The real option analyses (ROA) concept has proven to be viable because of the variability in DERs and changes in real-time load as discussed in this dissertation. The DER valuation is highly case sensitive, and many special factors may have an effect on its value. In this thesis, the factors with the highest impact have been considered, however, there could be additional factors with lower impacts which usually depend on the utility planning and operation. The essence of such factors is further discussed as part of the future work are briefly explained at the end of the thesis.
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