# On the Determination of Meshed Distribution Networks Operational Points after Reinforcement
## 1 Introduction  
Medium and low voltage distribution networks are mostly operated as radial; however, in some exceptional cases, they can be connected as meshed or in loops [1]. Radial circuits have many advantages over networked circuits, including easier fault current protection, lower fault currents over most of the circuit, easier voltage control, easier prediction and control of power flows and lower installation cost [2]. On the other hand, meshed networks demonstrate performance improvements and efficiency increase. The reinforcement of already existing distribution networks is an issue of priority for network operators, in an effort to ensure the uninterruptable power supply. Several works have been developed to investigate reinforcement issues in radial and meshed distribution level and to provide adequate simulation tools and methods. [PERSON] et al. [3] demonstrated the benefits of meshing the network instead of reinforcing it. [PERSON] et al. [4] provided a procedure to improve networks' performance taking into consideration the advantage of its meshed development. The networks operate in radial mode even if they are built as meshed. This article proposes a control method to optimally rearrange the radial network. Nevertheless, in this case the network continues to operate radially. Moreover, several planning methods take into consideration that optimal solutions can lead to meshed networks [5], even if they are weakly meshed. Recently, optimization for distribution network planning has led to substantial research activity even if part of the researcher community still supports, to a certain degree, the benefits of distribution system radial operation [6]. Added to the above, the increasing use of electric vehicles and the consequent impact on the operation of the network has to be taken into consideration. Note that the penetration level of electricvehicles is higher in the countries where the appropriate infrastructure is widely available [7]. Hence, their charging and their interaction in general with the electricity network can be controlled remotely in a safe manner, maybe by a charging service provider (CSP) [8; 9] or on individual vehicle basis [10]. Given the already major resources provided to build the infrastructure, their charging can be prioritized on grid requirements. This would on one hand meet possible infrastructure constraints and on the other hand improve electricity system performance, even though new significant load is added. Furthermore, this procedure would offer time for system reinforcements, if these are needed. However, system inertia exists in the system, and hence, controlled charging has to be achieved gradually [11]. It can start from lower penetration of electric vehicles and random charging when needed, up to the level where electric vehicles would charge only when grid has the essential capacity to allocate in this exercise. In this way, electric vehicles are behaving as battery storage [12]. The proposed procedure would also be enhanced in the future from improved battery performance connected to enhanced electric vehicle range that would reduce driver anxiety. However, in any case, this approach could decrease vehicle owners' satisfaction who are used to a continued service currently offered from fossil fuel powered vehicles. This approach could also possibly deteriorate battery condition. Of course, on the other hand, drivers' behavior affects, in a different manner, electricity systems [13]. Additionally, it could create discomfort to the industry [14] that is going to implement the incentive, but the benefits are more important to the effort. It has to be mentioned that electricity companies already have the experience in operating demand side management programs, restricted by the limited communication resources of the past. These demand side management programs are not considered as suitable for electric vehicles optimal charging [15].