Photovoltaics and opportunistic electric vehicle charging in the power system – a case study on a Swedish distribution grid

Abstract

Renewable distributed generation and electric vehicles (EVs) are two important components in the transition to a more sustainable society. However, both pose new challenges to the power system due to the intermittent generation and EV charging load. In this case study, a power system consisting of a low-and medium-voltage rural and urban distribution grid with 5174 customers, high penetration of photovoltaic (PV) electricity and a fully electrified car fleet were assumed, and their impact on the grid was assessed. The two extreme cases of two summer weeks and two winter weeks with and without EV charging and a PV penetration varying between 0% and 100% of the annual electricity consumption were examined. Active power curtailment of the PV systems was used to avoid overvoltage. The results show an increased electricity consumption of 9.3% in the winter weeks and 17.1% in the summer weeks, a lowering of the minimum voltage by one percent at the most, and a marginal contribution by the EV charging to lower the need of PV power curtailment. This shows the minor impact of EV charging on the distribution grid, both in positive terms of allowing more PV power generation, and in negative terms of lower voltage levels.

Modeling and Forecasting Electric Vehicle Consumption Profiles

“…With adequate planning, there should be no major problem with such market share growth. This is in line with other studies assessing the impact of EV charging, such as Luthander's et al in a Swedish case [33]. However, since there could be issues at a local scale, some kind of coordination is required to smart-charge the EVs [6], for instance by optimally scheduling the charging of EV fleets [34], or through targeted price incentives [35].…”

Overview of Loss Sensitivity Analysis in Modern Distribution Systems

“…For instance, [121]- [125] propose optimal planning strategies of G2V-based EV planning for improving system indicators including loss reduction. The planning problem can be formulated as optimal placement and sizing of charging stations across the system [126], [141]. For loss sensitivity calculations in G2V planning, few studies use linear approximation of annual losses [122], [127], [129] whereas others use classical load flow analysis [123], [125] or NSFs [124].…”

Feasibility Investigation for Residential Battery Sizing Considering EV Charging Demand

“…The PV generation in residential grids [8][9][10] and the impact of EV charging on the residential grid have been discussed in [11][12][13][14]. While the benefits of PV and EV integration have multiple benefits [15][16][17][18], the large-scale PV and EV deployment can also impose extra challenges in the local grids.…”