# Impact of the Integration of the Electric Vehicle on Low-Voltage Rural Networks
## 2 Background
Among the cases studied, they did not consider the exclusive use of EV chargers without the support of PV systems. One of the major problems caused by the massive use of single-phase chargers is the appearance of unbalances in the grid and their consequences. They can jeopardize the functionality of the distribution grid, and the effects have been thoroughly examined in [29; 30; 31]. The key problems include:  
* _Neutral Conductor Overload_. The current through the neutral wire is the sum of the current of the three phases (1). A sufficiently large current can lead to cable heating, degradation, and potential failures [32]. \[\mathbf{I}_{n}=\mathbf{I}_{a}+\mathbf{I}_{b}+\mathbf{I}_{c}\] (1)
* _Distribution Transformer Overheating_. The zero-sequence current magnetic flux closes through the oil tank wall of the distribution transformer (DT), resulting in heat generation, increased losses, and reduced equipment lifespan [33]. * _Voltage Quality Reduction_[34; 35]. * _Line Losses Increase_, caused by neutral line losses and suboptimal distribution of phase currents [36]. * _Abnormal vibration and malfunction in induction equipment_, such as rotating machines [37; 38; 39]. * _Mal-operation of Protection Relays_[39]. * _Increase in Neutral to Ground Voltage_[32; 40]. It is clear that the charging process of electric vehicles in rural networks strongly impacts the network characteristics and can be a barrier to deploying these vehicles. Several authors proposed methods to minimize the impact of imbalances and improve the quality and reliability of the electrical supply. These methods can be categorized into two groups: those based on reconfiguration techniques and those using electronic devices for current compensation [30]. Reconfiguration techniques include the reconfiguration of the distribution feeder, aiming to change the topological structure of the network by altering the state of switches in the distribution feeder [41; 42] and the phase balancing technique, which modifies the phase connection between phases through phase swapping [43; 44]. The use of electronic devices focusing on current compensation to mitigate the effects is further divided into three progressive approaches. The first is the Increase Nominal Capacity method, which mitigates imbalances by enhancing the nominal power capacity of equipment, such as oversizing protections, distribution transformers, cables, or even separating the neutral conductor [36]. The second approach involves special transformer configurations, utilizing transformers that are more resistant to unbalances, such as the T-connected transformer, Scott transformer, or star-hexagon transformer. Additionally, active filters can be added to the DT [39; 45; 46; 47]. Lastly, the Shunt Active Power Filter (APF) method aims to reduce imbalances by installing shunt APFs with commonly used topologies, including three single-phase H-bridge, 3P-4W with midpoint capacitor, and 3P-4W with four legs (4L) [48; 49; 50]. From the above, it can be concluded that there are still no studies on the impact of electric vehicle charging in rural networks that detail the low-voltage distribution network with a significant number of inhabitants. Furthermore, it is necessary to consider users' habits in using their vehicles, among which the availability and proximity of the vehicle in the event of any contingency prevail, which translates into non-centralized charging processes in homes to the maximum possible extent that the batteries allow.