IEEE Electrification Magazine - March 2020 - 16

implementation area in crowded cities are the main disadvantages of this type.

Even though the low-power-value LVdc hub may not
be suitable for megachargers and ultrafast charging
systems, it will be effective for mid- and fast-charging
systems. Mid- (up to 25 kW) and fast- (up to 150 kW) charging infrastructures are commonly used today, equipped
with Combo (one in the United States and two in Europe)
and/or Chademo plugs. These are able to charge most of
the current EVs and all of the upcoming EVs, preferably
with the Combo connection for its wider diffusion. Due to
the low power value, it is better if they are connected to
the LV DRMG with low-power PV generators. These systems must be able to charge vehicles equipped with

Charging infrastructures for EVs
One of the prominent features of DRMG is the integration
of charging infrastructures for EVs directly in the dc section.
This solution has the advantage of direct exploitation of
renewable sources and braking energy from the trains minimizing the impact on the ac mains. In addition, this moves
toward a sustainable mobility system since it facilitates the
intermodality both for passenger journeys, e.g., train plus
electric car sharing, and for goods in intermodal terminals.

ac Mains

ac Mains

Main Grid
Supply Train
3~

RBE Is Fed
Back to
the Grid

Onboard ESS

ac/dc
= Substation

ac/dc
Substation

MVdc (7.5-24-kV)
Catenary System

3~
=

RBE Supply Adjacent Train

G
3~

=

Integration of
Distributed Energy
Resources
(Renewables,
Storage
Systems, ...)

High-Power
Photovoltaic

=

Storage
Systems

=
dc Energy Hub

Wind
Generation

=

Opportunity
Charge for
Electric Buses

=
=

Ultrafast Charging
Stations for
Electric Vehicles

=
=

Megacharger
for Trucks
and Semis

=
=
=

dc Energy Hub
=
=

Elements Directly Connected
to the ac/dc Substation

I E E E E l e c t r i f i cati o n M agaz ine / MARCH 2020

=

Storage
Systems

=

Opportunity
Charge for
Electric Buses

=

=

Ultrafast Charging
Stations for
Electric Vehicles

=
=

Megacharger
for Trucks
and Semis
dc Energy Hub

=

=
=

=

=
=

Integration of
Ultra-Power
Charging
Systems

Low-Voltage
dc Busbar

=

Integration Busbar
of Low-Power
Renewables
Charging
Infrastructures
and LVdc
Subway
Systems

LV DRMG

Integration of
Distributed Energy
Resources
(Renewables,
Storage
Systems, ...)

High-Power
Photovoltaic

7.5-24-kVdc

Low- and
Mid- Power Mid- and
LVdc Photovoltaic Fast- dc
Subway
Charging
Systems
Stations

16

=

=

=

Figure 3. The MV DRMG system architecture.

Wind
Generation

G
3~

=

=

=
=

3~

=

Low-Voltage
dc Busbar

=
7.5-24-kVdc
Busbar

Integration of
Ultra-Power
Charging
Systems

=

dc Energy Hub

3~
=

=

Low- and
Mid- Power Mid- and
LVdc
Photovoltaic Fast- dc
Subway
Charging
Systems
Stations
Elements Connected
to the MVdc Contact Line

Integration of
Low-Power
Renewables
Charging
Infrastructures
and LVdc
Subway
Systems

LV DRMG
IEEE Electrification Magazine - March 2020

Table of Contents for the Digital Edition of IEEE Electrification Magazine - March 2020
