# Energy Management Scheme for an EV Smart
## 1 Introduction  
New policies regarding CO\({}_{2}\) emission control have encouraged the penetration of renewable energy in the power generation sector and electric vehicles (EVs) in the transportation sector. Renewables such as photovoltaics and wind turbines are being integrated into the distribution system as distributed generation (DG) systems [1]. Both photovoltaics and wind turbines give fluctuating power output owing to the intermittent nature of their energy source. The resulting power imbalance can cause instability in the grid due to the distribution transformer overloading and the line congestion in low power periods [2]. It is not feasible for conventional generators with high response times to compensate for such rapid power changes [3]. Although, the battery energy storage systems (BESSs) with a power electronics interface have high ramp rates and quick response times well suited for renewables application [4], they increase the overall system and operating costs [5]. Solar power fluctuations can be smoothed by smaller batteries [6], giving rise to the prospect of utilizing EV batteries in cooperation with renewables. Though the penetration of EVs in the distribution grid has increased [7], EVs are parked and connected to the grid either in charging mode or idle mode for more than 95% of the time [8]. The probability of an EV parked anywhere during the midday period is over 0.9, and parked any day at home is higher than 0.5. From the perspective of developed countries, two vehicles per household and one being parked at home most of the time is a reasonable assumption [9]. According to [10], more than 90% of vehicles are parked at home for one-third of the day. As such, studies show that the daily mileage of EVs is not much, and they are parked the majority of the time. Furthermore, at any instance during the day, the presence of EVs parked and connected to a charger is a high possibility. If the parked EVs are maintained to be plugged in and connected to the grid for the entire parking duration, the potential of utilizing the EVs for vehicle-to-grid (V2G) or grid-to-vehicle (G2V) services is promising. This application of EVs can reduce the overall costs of purchasing and maintaining BESS units and results in economic benefits for distribution system operators (DSOs). Moreover, the price-based energy flow schemes encourage EV owners to participate in them, and the EVs serve as a source of revenue for their owners, promoting the EV market. Furthermore, when EVs are charged from renewables and discharged during the power deficit, the renewables are utilized to their maximum economic and environmental support potential [11]. Otherwise, charging EVs from the energy generated from conventional power plants simply shifts the carbon footprint from the vehicle exhaust systems to power plants. In addition, the stress on the grid is lessened when power is generated in the close vicinity of charging EVs. Making the EV ready for departure at all times has accelerated the installation of off-board fast charging stations, which have been a focus of recent research for V2G/G2V operation and reactive power support. A control scheme for a unified four-quadrant operation of a three-leg inverter for three-phase fast charging and single-phase slow charging has been developed in [12]. In [13], the capacitive and inductive operation of an off-board bidirectional EV charger is explored, incorporating user-based charging commands. Control of active and reactive power by utilizing a three-phase grid-tie inverter with anti-islanding detection and voltage/frequency deviation protection has been proposed in [14]. Various studies have addressed active power control in compliance with inverter DC-link voltage and the reactive power with point of common coupling (PCC) voltage [15; 16; 17]. However, it is more suitable and standardized to communicate active power \(P\) and reactive power \(Q\) reference signals between the charger and the grid, and to derive other references based on these \(PQ\) references [18].