A Multi-Layer Coordinated Control Scheme to Improve the Operation Friendliness of Grid-Connected Multiple Microgrids

Abstract

Multiple microgrids (MMGs) are clusters of interconnected microgrids that have great potential for integrating a large number of distributed renewable energies (DREs). The grid-connected control scheme is important for the exploration of the MMGs’ operation potential. In this paper, a multi-layer coordinated control scheme for DC interconnected MMGs is proposed to optimize their operation and improve their operation friendliness. An adaptive droop control method is designed for the DC connection interfaces of the MMGs to adaptively manage the power exchange among the sub-microgrids. Meanwhile, the strategy of power fluctuation suppression is developed for the hybrid energy storage system (HESS) in the MMGs. The coordination among the sub-microgrids and the HESS is then clarified by the proposed control scheme to optimize the AC tie-line power and make the MMGs a highly coordinated collective. A case study is performed in PSCAD/EMTDC based on the demonstration project in Guangxi, China. The results show that the proposed multi-layer coordinated control scheme realizes the coordinated operation of the MMGs, fully exploits the complementarity of the MMGs, and improves the operation friendliness among the sub-microgrids and the utility grid. Thus the integration and utilization of a large number of DREs is enhanced.

Adaptive and Fuzzy PI Controllers Design for Frequency Regulation of Isolated Microgrid Integrated With Electric Vehicles

“…Various kinds of microgrid's (MG) dynamic model is presented by researchers to assess the frequency regulation in the MG [13], [14], [23]. To evaluate the frequency regulation of isolated MG integrated with RESs and EVs the system equation is given below:…”

“…All the EVs, whose SOC is less than SOC max , are set to charging. The following equations (11)(12)(13) are related to the flow chart.…”

“…Droop control techniques and their advanced versions are widely used for frequency regulation of the power system due to the absence of communication links [12]. The droop control mechanism in synchronous generators is used to regulate the output power according to the load variations in allowable limits in multiple microgrids [13]. In the meantime, the ESS approach is developed which mimics the droop characteristic of the synchronous generator to counter the effect of power fluctuation and provide frequency support to isolated MG [14].…”

Amultimicrogridenergy management model implementing an evolutionary game‐theoretic approach

“…However, this classification was only based on the credibility of extreme machine learning method. Grid‐connected MG was involved in energy management 38,39 . A centralized MMG was handled with the deployment of a bidding strategy.…”

Risk‐averse microgrid cluster switching approach for improving distribution system characteristics considering uncertainties of renewable energy resources

“…The proposed strategy is considered as an essential technique for improving the system resilience. A three‐level multi‐layer control strategy is introduced in [14], which coordinated the operation strategies of energy storage devices and sub‐MGs. This control strategy can boost the integration capacity of RESs into the network.…”