Electric vehicles: Battery capacity, charger power, access to charging and the impacts on distribution networks

Abstract

The battery electric vehicle (EV) market is in a state of continuing rapid evolution, both in terms of the battery capacities and charger power ratings that vehicle manufacturers are bringing to the market and the increasingly widespread penetration of charging infrastructure. As a result, individuals' charging behaviours may change substantially and be different from what has been expected or observed to date. This could have a significant effect on the resulting electrical demand from EV charging. Aside from these technical parameters, the demographics of the population served by any given network -and how that might affect their travel habits, particularly car use -must be considered. In this paper, statistical analysis of a large travel survey dataset is carried out to support the hypothesis that car use is likely to vary according to population demographics. Car-based travel diaries disaggregated on key demographic traits of the drivers are assigned to vehicles in the network according to Census data pertaining to those same demographic traits. Charging schedules are derived from these travel diaries for different battery capacities, charger power ratings and level of access to charging to investigate the likely effect of changing these parameters on the resulting charging behaviour and electricity demand. It is found that out of the key emerging patterns identified in the evolving EV market, increasing battery capacities and the establishment of more widespread charging opportunities may reduce the peak demand from EV charging or shift it to a time less likely to coincide with peak domestic demand, hence making it easier for the network to cope with increasing penetrations of EVs. On the other hand, increasing charging power may increase the peak and bring it closer to a time where it is more likely to coincide with peak domestic demand.

Magyarország térinformatikai alapú gyorsforgalmi átjárhatósági vizsgálata az elektromobilitás szempontjából– helyzetkép és fejlesztési lehetőségek

“…Ugyanakkor fontos hangsúlyozni, hogy az elektromos autók és a töltőhálózat gyors fejlődése is gyorsan amortizálja a téma kutatása során felszínre kerülő összefüggéseket és eredményeket. Az akkumulátor-kapacitások növekedése elméletileg a töltőpont-hálózat térbeli ritkulásához is vezethetne, ám az elektromos járművek számának gyors növekedése ezzel ellentétes folyamatot generál, miközben a szinte naponta telepített új töltőpontok gyorsan rajzolják át a korábban felvázolt képet (Dixon, J. -bell, K. 2020).…”

A practical approach to predict volume deformation of lithium‐ion batteries from crystal structure changes of electrode materials

“…In this paper, a practical approach is proposed to predict battery volume deformation from crystal volume changes of electrode materials, as shown in Figure 3. Take the charging process as an example, the deformation of lithium-ion battery D fullcell can be calculated by Equation (1). D ca (y) and D an (x) are the crystal volume changes of cathode and anode as functions of lithium stoichiometry y and x, respectively.…”

“…Once the variations of lithium stoichiometry in cathode and anode during charging are determined, we can calculate the battery deformation according to Equation (1).…”

“…Lithium-ion batteries are the most widely-used power sources for electric vehicles, considering their high energy density and long cycle life. [1][2][3] In recent years, to extend the total driving range of electric vehicles, battery, and vehicle manufacturers are increasing the energy density of battery systems by packing cells closely. [4][5][6] However, lithium-ion batteries suffer from volume deformation during operation, which will lead to increased stress inside the module or pack and then affect battery cycle life and even safety.…”

“…Lithium‐ion batteries are the most widely‐used power sources for electric vehicles, considering their high energy density and long cycle life 1‐3 . In recent years, to extend the total driving range of electric vehicles, battery, and vehicle manufacturers are increasing the energy density of battery systems by packing cells closely 4‐6 .…”