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The global warming problem together with the environmental issues has already pushed the governments to replace the conventional fossil-fuel vehicles with electric vehicles (EVs) having less emission. This replacement has led to adding a huge number of EVs with the capability of connecting to the grid. It is noted that the presence of such vehicles may introduce several challenges to the electrical grid due to their grid-to-vehicle and vehicle-to-grid capabilities. In between, the power quality issues would be the main items in electrical grids highly impacted by such vehicles. Thus, this study is devoted to investigating and reviewing the challenges brought to the electrical networks by EVs. In this regard, the current and future conditions of EVs along with the recent research works made into the issue of EVs have been discussed in this study. Accordingly, the problems due to the connection of EVs to the electrical grid have been discussed, and some solutions have been proposed to deal with these challenges.

Contrary to reliability analysis in power systems with the main mission on safely and securely withstanding credible contingencies in day-today operations, resilience assessments are centered on high-impact low probability (HILP) events in the grid. This paper proposes an autonomous load restoration architecture founded on IEC 61850-8-1 GOOSE communication protocol to engender an enhanced feeder-level resilience in active power distribution grids. Different from the past research on outage management solutions, most of which (a) are not resilience-driven, (b) are reactive solutions to local single-fault events, and (c) do not address both network built-in flexibilities and flexible resources, the proposed solution harnesses (a) the imported power and flexibility from the neighboring networks, (b) Distributed Energy Resources (DERs), and (c) vehicle to grid (V2G) capacity of Electric Vehicles (EVs) aggregations to enhance the feeder-level resourcefulness for agile response and recovery. Through real-time self-reconfiguration strategies, the suggested solution is capable of coping both single and subsequent outage events, and will engender a heightened resilience before and during the contingency period. Moreover, a resilience evaluation framework, which quantifies the contribution of all resources involved in service restoration, is developed. Real-time performance of the designed architecture is evaluated on a realworld power distribution grid using a real-time Hardware-in-the-Loop (HIL) platform. Numerical case studies through a number of diverse scenarios demonstrate the efficacy of the proposed restoration solution in practicing an enhanced resilience in power distribution systems in response to HILP scenarios.

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In this paper, an Internet of Things (IoT) platform is proposed for Multi-Microgrid (MMG) system to improve unbalance compensation functionality employing three-phase four-leg (3P-4L) voltage source inverters (VSIs). The two level communication system connects the MMG system, implemented in Power System Computer Aided Design (PSCAD), to the cloud server. The local communication level utilizes Modbus Transmission Control Protocol/Internet Protocol (TCP/IP) and Message Queuing Telemetry Transport (MQTT) is used as the protocol for global communication level. A communication operation algorithm is developed to manage the communication operation under various communication failure scenarios. To test the communication system, it is implemented on an experimental testbed to investigate its functionality for MMG neutral current compensation (NCC).To compensate the neutral current in MMG, a dynamic NCC algorithm is proposed, which enables the MGs to further improve the NCC by sharing their data using the IoT platform. The performance of the control and communication system using dynamic NCC is compared with the fixed capacity NCC for unbalance compensation under different communication failure conditions. The impact of the communication system performance on the NCC sharing is the focus of this research. The results show that the proposed system provides better neutral current compensation and phase balancing in case of MMG operation by sharing the data effectively even if the communication system is failing partially.Energies 2018, 11, 3102 2 of 22 control the neutral current directly [3], where the 3P-4L voltage source inverter (VSI) provides better unbalance compensation than other active and passive methods [4]. Traditionally, a fixed portion of the 3P-4L converter capacity is specified to compensate the neutral current. However, the drawback of this method is in case of higher neutral current compensation (NCC) necessity, where it can lead to increased capacity of the 3P-4L compensator [5]. Authors in Reference [6] employed the 3P-4L VSI with PV installation to compensate for the neutral current but case scenarios for network interaction with different loads are not presented. A fixed capacity neutral current compensation method employing 3P-4L VSI under various load scenarios for network contingencies cases is proposed in Reference [7]. Furthermore, the 3P-4L VSI is used to eliminate the leakage current from PV installations [8]. However, none of these researches have considered higher capacity requirement. Authors in Reference [9] propose a dynamic capacity distribution method to compensate for the neutral current utilizing the maximum capacity of the VSI in a Microgrid (MG) but no communication system in presented. Authors in References [10,11] have employed conservative power theory to share the residual neutral current among the VSIs in an MG. Although a communication system have been employed, its operational details are not presented. Cloud-based Internet of Things (IoT) platforms to manage energy of building...