Article

# Energy Management of CHP-Based Microgrid with Thermal Storage for Reducing Wind Curtailment

Authors:
• CROM Center for Research on Microgrids - Aalborg University
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## Abstract

A large amount of wind energy curtailment is observed during the winter off-peak period in northern China. Because heat demand is high but electric demand is low, combined heat and power (CHP) units have to generate power to supply heat, leaving no load for wind farms to serve. To solve this problem, this paper proposes an energy management method to take advantage of the flexibility in different heating resources in a CHP-based microgrid to relieve wind power curtailment. A novel two-layer coordinated strategy (a schedule layer and a real-time layer) is proposed to control all the components including distributed generation (DG) units, different heating sources, and electrical energy storage (EES). In the schedule layer, a centralized optimization model based on forecasting data is implemented. The real-time layer calculates control signals based on metrical data and received reference values from the upper layer. Flexible control of EES and electric heater scheme (FCEE) is developed to further increase grid integration of wind generation. A 14-bus test system is designed to illustrate the performance of the proposed approach. Results show that the presented method is able to significantly reduce wind curtailment and ensure promising operation efficiency of the studied CHP-based microgrid.

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... Due to the natural intermittent property, wind power can not be dispatched on demand. When the available wind power excess the operation capability of the integrated power grid, wind curtailment has to be performed to keep power balance in the system, which leads to an critical issue of massive wind generation curtailment during the winter off-peak period in Northern China [1]. To ensure the utilization of wind power, the Government of China has also issued a set of policies to guide market design and technology development [2]. ...
... Therefore, additional flexibility resources need to be introduced in heating supply to allow CHP units to further reduce their power output for relieving wind generation curtailment. Installing electrical boilers (EB) is one of the potential solutions that can utilize wind generation to meet the heat load demand [1]. Electrical energy storage has also been widely applied to increase the flexibility in island microgrid operation [14]. ...
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The uncertainty and intermittency of the available wind resource in nature would potentially cause wind generation curtailment when the flexibility of the integrated power grid is limited, especially in small-scale microgrids for islands. In this paper, an optimal configuration method is proposed to use thermal energy storage (TES) to relieve wind generation curtailment in an island microgrid. The thermal network is modeled along with the electrical network to utilize its regulation capability, while TES is introduced as an additional flexibility resource. The detailed cost models of combined heat and power (CHP) units and TES are presented to realize the objective of minimizing the overall operating cost. The performance of TES in improving wind power utilization is firstly validated by using an electrical boiler (EB) as a benchmark and further analyzed under different scenarios considering the growths of wind power capacity, electrical load, and heat load. The effectiveness of the proposed method is validated using real-world data obtained from the practical island microgrid.
... In [6], scheduling electric vehicle charging to minimize carbon emissions and wind curtailment is proposed. In [7], energy management of CHPbased microgrid with thermal storage for reducing wind curtailment is proposed. In [8], analysis of energy storage systems to exploit wind energy curtailment in Crete is carried out. ...
... These efforts have considered a range of approaches that can be roughly classified as deterministic methods or scenario-based stochastic programming. Specifically, some authors (Cheng et al. 2018;Hu et al. 2013;Ghasemi and Enayatzare 2018;Hosseinnezhad et al. 2016) incorporated uncertainty via a deterministic optimization framework with a single expected forecast for the uncertain inputs. Subsequently, deterministic rolling-horizon approaches have been implemented to take advantage of updated information as the model moves through the operation time frame, still in a deterministic formulation (Zhang et al. 2016;Kalavani et al. 2019;Qureshi et al. 2014;Borsche et al. 2014;Palma-Behnke et al. 2013). ...
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... A few study based on superconducting magnetic energy storage for enhancing MG operation and controls are reported in [33][34][35]. Thermal energy storage for MG applications are presented in [36][37][38]. Using hydrogen to support energy back up for microgrid operation are investigated in [39][40][41][42]. ...
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... Dai et al. (2017) have studied the modeling of active thermal storage (ATS) and passive thermal storage (PTS) in a combined heat and power (CHP) plant. Also, in Cheng et al. (2018) energy management of CHP-based microgrid has been performed by thermal storage in order to reduce wind curtailment. Zou et al. (2019) have solved the CHPED problem by an improved genetic algorithm and a new constraint handling strategy. ...
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Application Guide for SCR Controlled Electric Heat
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