  With the considerable increase of Distributed Energy Resources (DER), the
reliable and cost-effective operation of the electricity distribution grid
becomes challenging. This relies on computationally dependable and tractable
optimisation solvers, which may handle: 1) non-linear AC power flow
constraints, and 2) the multiple numbers of input variables and objectives of
DER, over the operational horizon. In this paper, we introduce an application
of a high-performance MultiPeriod AC Optimal Power Flow (MPOPF) solver, called
"BATTPOWER", to simulate active distribution grids for a near-future scenario.
A large-scale Norwegian distribution grid along with a large population of
Electric Vehicles (EV) are here taken as the case-study. We suggest and analyse
three operational strategies for the Distribution System Operator (DSO): (a)
uncoordinated (dumb) charging, (b) coordinated charging with the objective of
energy cost-minimisation, and (c) coordinated charging with the objective of
energy cost-minimisation along with operational constraints of the grid. The
results demonstrate that the uncoordinated charging would lead to: 1)
overloading of lines and transformers when the share of EVs are above 20\%, and
2) higher operational costs than the proposed control strategies of (b) and
(c). Although the implementation of strategy (b) is not difficult to apply,
nonetheless operational line/transformer limits are violated when the
populations of EVs are growing above 36\%. This implies that current market
design must be altered to allow active control of a large proportion of DERs
within grid operational limits to achieve cost minimization at system level.
