# Review of Communication Technologies for Electric Vehicle Charging Management and Coordination
###### Abstract  
Recently, electric vehicles (EVs) have been introduced as an alternative method of transportation to help mitigate environmental issues, such as carbon emissions and fuel consumption, caused by conventional transportation systems. The implementation of effective EV charging systems is essential to motivate mass adoption of EVs. Accordingly, fast and reliable communications between the charging systems and the EVs are vital for efficient management of the charging process. Different radio access technologies (RATs) are discussed in the literature to enable communication between the highly mobile EVs and the charging subsystems, to collect and exchange information such as state of charge (SoC), users' locations, and charging decisions between the different network entities. This information can be used to coordinate charging plans and select the optimal routes for moving vehicles. This paper presents a survey of existing literature on vehicular communications for EV charging coordination and management. The communication requirements and feasible communication technologies for vehicular communication are first discussed in details. A review of the physical layer security strategies is then presented and the role of the different RATs in EV charging coordination and management is described and studied. electric vehicles; IoEV; vehicle-to-vehicle (V2V); vehicle-to-infrastructure (V2I); dynamic charging; direct short-range communication (DSRC); C-V2X; NR-V2X; physical layer security; charging coordination; scheduling +
Footnote †: journal: Applied Electric. Vol. 1  
Wired charging requires direct physical connectivity between the EV and the charging socket, thereby imposing an electrocution hazard to the EV user, particularly during harsh weather conditions. To overcome this hazard, effective electrical isolation is required between the EV body, the EV supply equipment (EVSE) and the mains power grid, using high-frequency isolation transformers [3] or other isolation techniques. These transformers, however, are costly to implement and maintain, and they impact the switching operation of the EV chargers. In addition, hardware compatibility between the EV charging connector and the charging inlet point is essential to enable wired EV charging [9]. This impacts the convenience to EV users, as it limits the locations at which an EV can be charged to those compatible and/or interoperable with the EV connector. In contrast, wireless charging is adopted as an alternative charging method, where no physical connection is required between the EV and the power source. Wireless charging is becoming more common due to its flexibility, convenience and, more importantly, higher safety factor. It is commonly categorized into three modes: static charging, dynamic charging, and quasi-dynamic charging [10; 11]. In static charging, energy is transferred from the grid to the EV using inductive wireless power transfer while the EV is parked over a wireless charging pad. A dynamically charged vehicle, on the other hand, receives the charging energy wirelessly during its motion over a set of coils placed on the road [12; 13]. Quasi-dynamic charging is an integration of the two modes in which the EV is charged during transient stops at intersections and traffic signals [14]. By allowing an EV to receive energy wirelessly during its motion, the range anxiety of EV drivers can be significantly reduced, particularly in cities with large traveling distances between the different locations. Dynamic wireless charging (DWC) also eliminates driving delays due to EV charging downtime [15] and introduces opportunities for EV battery downsizing and EV price reduction [16; 17].