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a b s t r a c tThis paper presents a three-layered coordinated control to incorporate three-phase (3P) alternating current (AC) and direct current (DC) type electric vehicle energy storage systems (EV-ESSs) for improved hybrid AC/DC microgrid operations. The first layer of the algorithm ensures DC subgrid management by regulating the DC bus voltage and DC side power management. The second and third layer manages AC subgrid by regulating the AC bus voltage and the frequency by managing reactive and active power respectively. The multi-layered coordination is embedded into the microgrid central controller (MGCC) which controls the interlinking controller in between AC and DC microgrid and the interfacing controllers of the participating electric vehicles (EVs) and distributed generation (DG) units. The whole system is designed in MATLAB/SIMULINK Ò environment resembling the under construction microgrid at Griffith University, Australia. Extensive case studies are performed using real life irradiation data and commercial loads of the campus buildings. Impacts of homogeneous and heterogeneous single-phase EV charging are investigated to observe both balanced and unbalanced scenarios. Synchronization during the transition from the islanded to grid-tied mode is tested considering a contingency situation. From the comparative simulation results it is evident that the proposed controller exhibits effective, reliable and robust performance for all the cases.

This paper presents a need-based distributed coordination strategy (NDCS) for multiple electric vehicle (EV) storages in an islanded commercial hybrid alternating-current (AC)/direct-current (DC) microgrid. The control capacity of the interlinking converter is enhanced by incorporating combined power-droop and voltage-droop strategies to leverage the coupling of AC and DC voltages. Therefore, the AC bus voltage can be regulated simultaneously by regulating only the DC bus voltage without affecting the power-sharing capabilities of the converter. The NDCS is proposed to coordinate the EV storages to regulate the DC bus voltage. The main objective of the NDCS is to decide whether the coordination of the available EV storages is to be done in a decentralised or a distributed manner. The mathematical model and the algorithm to deploy NDCS are developed to realise its application to a real system. The effectiveness of the control system is verified in a commercial hybrid AC/DC microgrid comprising one photovoltaic (PV) unit and four EV storages directly connected to the DC bus via DC/DC converters and four distributed-generation (DG) units connected to the AC bus using the conventional droop-control scheme. The performance of both controllers is tested under variable irradiation, commercial loading and various fault conditions. The results of the case studies demonstrate the efficacy of the overall system in terms of robustness for a variable generation-demand scenario, time delay, EV plug-and-play and fault conditions.

Powering small islands with reliable, affordable and green electricity is a big challenge due to their dispersed geographical location with limited number of consumers and the heavy dependence on fossil fuels. This paper aims to address this challenge of reducing dependency on fossil fuel generators by providing an easy and feasible solution using available and accessible energy resources. The proposed method utilizes the bidirectional energy transfer mechanism available in electric boats to support the consumers' power demand. It proposes a new realtime load-support (RTLS) system with a coordinated control using electric boats (EBs), community generators and battery energystorage systems. It analyzes the management of the intermittent sources-dependent small-scale grid in real time, under various weather, load, and battery state-of-charge conditions. The RTLS system coordinates the customers' load demand with the available EBs, photovoltaics (PVs) and battery storage to provide efficient load support and to regulate the bus voltage and frequency. The efficacy of the proposed system is validated both computationally in a real network and in a laboratory setup. It is found that this novel system can substantially reduce the grid load demand and maintain the power quality under various load/source uncertainties and fault conditions. The system robustness is also evaluated considering undesirable conditions, such as severe threephase faults and sudden EB disconnections. The performance of the proposed method is compared with that of the day-ahead loadmanagement approach to validate its effectiveness under various scenarios. Index Terms--Ancillary support, electric boat, forecasting, island energy management, island power systems, load support. NOMENCLATURE single PV module capacity efficiency of PV module , , , efficiency of converter 1, 2, 3, 4 current from PV , current from EB and battery respectively amount of power supplied from PV to AC bus amount of power supplied from PV to fixed battery EB battery capacity fixed battery capacity , max. charging limit of the EB and battery respectively , min. discharging limit of the EB and battery respectively , SOC of the EB and battery at a particular ( ) time

An improved vehicle-to-microgrid (V2M) framework is proposed for a commercial locality operating as a hybrid alternating-current (AC) / direct-current (DC) microgrid, which optimally coordinates electric-vehicle (EV) storages in a distributed manner. An aggregator model is proposed that solves the economic dispatch problem of parked EV storages in a centralized fashion and generates power references in real-time for the designed EV storage controllers. Unlike the conventional EV storage controller, the proposed optimizationincorporated distributed EV storage controller (ODC) can switch from decentralized to distributed control mode or vice versa based on situations and utilizes a sparse vehicle-to-vehicle (V2V) communication network.The power flow between the AC and DC subgrids is managed by interlinking converters (IC). The IC control structure is augmented by combining voltage-and powerbased droop-control schemes in the power control loop. This modification enables simultaneous AC and DC bus voltage regulations. Case studies are carried out to validate the efficacy of the developed framework with a real commercial network and loads. The results exhibit robust performance of the overall system for generation-demand variability, transitions between islanded and grid-tied conditions, and user-preferred EV disconnections and time delay. Index Terms-Hybrid AC/DC microgrid, economic dispatch, interlinking inverter, electric vehicles, distributed cooperative control.