EV charging stations and RES-based DG: A centralized approach for smart integration in active distribution grids

Renewable Energy Sources based (RES-based) Dispersed Generation (DG) and Electrical Vehicles (EVs) charging systems diffusion is in progress in many Countries around the word. They have huge effects on the distribution grids planning and operation, particularly on MV and LV distribution grids. Many studies on their impact on the power systems are ongoing, proposing different approaches of managing. The present work deals with a real application case of integration of EVs charging stations with ES-based DG. The final task of the integration is to be able to assure the maximum utilization of the distribution grid to which both are connected, without any upgrading action, and in accordance with Distribution System Operators (DSOs) needs. The application of the proposed approach is related to an existent distribution system, owned by edistribuzione, the leading DSO in Italy. Diverse types of EVs supplying stations, with diverse diffusion scenarios, have been assumed for the case study; various Optimal Power Flow (OPF) models, based on diverse objective functions, reflecting DSO necessities, have been applied and tried. The obtained results demonstrate that a centralized management approach by the DSO, could assure the respect of operation limits of the system in the actual asset, delaying or avoiding upgrading engagements and charges

Active distribution grids and EV charging stations: a centralized approach for their integration

The paper proposes real case of application of a smart integration of Electrical Vehicles (EVs) charging stations with Dispersed Generation (DG) that can guarantee the maximum exploitation of the system and its sustainability. The case study is a real distribution grid of e-distribuzione, the main Italian Distribution System Operator (DSO). Different kinds of EVs charging systems and spread scenarios are hypothesized and different Optimal Power Flow (OPF) models, with different objective function, reflecting different needs of DSO, have been implemented and tested. The analysis points out how a centralized management approach of EVs fast charging systems, by the DSO, might guarantee no violation of grid operation limits in the current configuration, postponing or escaping network upgrading actions and costs

Planning studies for active distribution grids in presence of EVs charging stations: simulation on a real test network

In the next future, a large spread of Electrical Vehicles (EVs) is foreseen, in accordance with the European policies and regulation dealing with environmental sustainability. It will lead to an important number of charging stations connections, whose number will be a function of the demand required by the EVs (traffic conditions, EV fleet and features, etc.), but they depend also on grid capacity, considering that they typically represent very variable loads for the grid. A “fit and forget” approach could involve the violation of grid operation limits and so the need of grid reinforcements (new MV and LV lines construction, primary and secondary substations expansion or new construction), thus causing relevant investments on the distribution grids. An intelligent management approach for EV charging stations could ensure the respect of the operation limits of the grids in the actual asset. The same approach should take into account the presence of DG and coordinate the RES energy production with the new EV charging stations consumption, solving technical problems such as the reverse power flow. In this way it should be possible to defer or avoid network reinforcements and development. The paper shows some results of a wide planning study performed on a real active distribution grid, including EVs charging stations connected to MV grid (public stations) and LV grid (home stations) in different EVs spread scenarios, according to European addresses, Italian policies, Enel guidelines and making a study of the territory where the distribution grid is located. Simulations have been carried out on the MV and LV grids connected to a HV/MV transformer. The complete analysis has been based on Power Flow (PF) and Optimal Power Flow (OPF) calculations performed using a MatLab tool. PF analysis gave the possibility to know the hosting capacity of the distribution grid for EV charging stations, pointing out if grid reinforcements are required. OPF analysis allowed evaluating the impact of a smart management approach, taking full advantage of the actual hosting capacity of the grid, suitably dispatching the EV charging stations. Many objective functions have been tested with the MatLab tool. Some of the results are reported in the paper for showing the benefits of the smart management approach in terms of grid reinforcements avoided

Active distribution grids and EV charging stations: a centralized approach for their integration

The paper proposes real case of application of a smart integration of Electrical Vehicles (EVs) charging stations with Dispersed Generation (DG) that can guarantee the maximum exploitation of the system and its sustainability. The case study is a real distribution grid of e-distribuzione, the main Italian Distribution System Operator (DSO). Different kinds of EVs charging systems and spread scenarios are hypothesized and different Optimal Power Flow (OPF) models, with different objective function, reflecting different needs of DSO, have been implemented and tested. The analysis points out how a centralized management approach of EVs fast charging systems, by the DSO, might guarantee no violation of grid operation limits in the current configuration, postponing or escaping network upgrading actions and costs

EVs charging stations in active distribution grids: A real case-study of smart integration

In Italy a large amount of Dispersed Generation (DG), mainly based on Renewable Energy Source (RES), has been connected in the last years to the distribution grids in Medium Voltage (MV) and Low Voltage (LV) grids of Enel Distribuzione, the main Distribution System Operator (DSO) in Italy, changing the electrical system from passive to active. The diffusion of Electrical Vehicles (EVs) is foreseen for the next future, in accordance with the European policies regarding environmental sustainability, resulting in another important change for the distribution grids: EVs charging stations will be realized as new connections with their very variable load towards the grid, in function of the demand required by the EVs. New planning and operation criteria are thus required for the electrical grid. This paper describes results of a wide planning study performed on a real active distribution grid of Enel Distribuzione, including different types of charging stations (public and home stations) in different EVs spread scenarios. The study shows how a smart management approach for EVs charging stations, recently proposed in many scientific papers, dispatching them taking into account DG and coordinating them with RES energy production, could ensure the respect of the operation limits of the grids in the actual asset, so deferring or avoiding network reinforcements