Research project “FastCharge”: ultra-fast charging technology ready for the electrically powered vehicles of the future.

Jettingen-Scheppach. The industrial companies
involved in the research project “FastCharge” yesterday presented the
latest advancements in the field of fast and convenient energy supply
for electrically powered vehicles. The prototype of a charging station
with a capacity of up to 450 kW was inaugurated in
Jettingen-Scheppach, Bavaria. At this ultra-fast charging station,
electrically powered research vehicles created as part of the project
are able to demonstrate charging times of less than three minutes for
the first 100 kilometres of range or 15 minutes for a full charge
(10-80 % State of Charge (SOC)).

The new charging station can be used free of charge right away
and is suitable for electric models of all brands with the Type 2
version of the internationally widespread Combined Charging System
(CCS), as is commonly used in Europe.

The research project “FastCharge” is being run by an industry
consortium under the leadership of the BMW Group; its other members
are Allego GmbH, Phoenix Contact E-Mobility GmbH,
Dr. Ing. h. c. F. Porsche AG and Siemens AG. “FastCharge” is receiving
total funding of EUR 7.8 million from the Federal Ministry of
Transport and Digital Infrastructure. The implementation of the
funding directives is being coordinated by NOW GmbH (National
Organisation Hydrogen and Fuel Cell Technology).


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Fast and convenient charging will enhance the appeal of
electromobility. The increase in charging capacity up to 450 kW –
between three and nine times the capacity available at DC
fast-charging stations to date – enables a substantial reduction in
charging times.
“FastCharge” is investigating the technical
requirements that need to be met in terms of both vehicles and
infrastructure in order to be able to tap into these extremely high
charging capacities.


The basis is provided by a high-performance charging
infrastructure. The Siemens energy supply system being used in the
project enables researchers to test the limits of the fast-charging
capacity demonstrated by vehicle batteries. It can already handle
higher voltages of up to 920 volts – the level anticipated in future
electrically powered vehicles. The system integrates both the
high-power electronics for the charging connections as well as the
communication interface to the electric vehicles. This charge
controller ensures the output is automatically adapted so that
different electric cars can be charged using a single infrastructure.
The system’s flexible, modular architecture permits several vehicles
to be charged at the same time. Thanks to high-current, high-voltage
charging the system is suitable for a number of different
applications, including fleet charging solutions and, as in this case,
charging along highways. In order to link the system to the public
power grid in Jettingen-Scheppach as part of the project, a charging
container was set up with two charging connections: one provides an
unprecedented charging capacity of max. 450 kW while the second can
deliver up to 175 kW. Both charging stations are now available for use
free of charge for all vehicles which are CCS-compatible.


The Allego charging station prototypes now presented use the
European Type 2 version of the well-established Combined Charging
System (CCS) charging connectors. This standard has already proved
successful in numerous electrically powered vehicles and is widely
used internationally.

In order to meet the demands of fast charging at high capacity,
cooled HPC (High Power Charging) cables made by Phoenix Contact are
used, which are fully CCS-compatible. The cooling fluid is an
environment-friendly mixture of water and glycol, allowing the cooling
circuit to be half-open. This makes maintenance comparatively
straightforward as compared to hermetically sealed systems that use
oil, e.g. in terms of refilling the cooling fluid.

One challenge was ensuring that the cooling hoses in the charging
line were not squeezed when connected to the charging station, as
would happen with a conventional cable gland. In the present instance
this would impair the cooling flow and therefore cooling efficiency.
This problem was solved by Phoenix Contact by means of a specially
developed wall duct with defined interfaces for power transmission,
communication and cooling as well as integrated tension relief.

Depending on the model, the new ultra-fast charging station can be
used for vehicles fitted with both 400 V and 800 V battery systems.
Its charging capacity automatically adapts to the maximum permitted
charging capacity on the vehicle side. The time saved as a result of
the increased charging capacities is demonstrated in the example of
the BMW i3 research vehicle. A single 10-80 % SOC charging operation
now only takes 15 minutes for the high-voltage battery, which has a
net capacity of 57 kWh. This can be achieved on the vehicle side by
means of a specially developed high-voltage battery combined with an
intelligent charging strategy. The latter includes precise
preconditioning of the storage temperature at the start of charging,
temperature management during the charging operation itself and a
perfectly coordinated charging capacity profile over time. The
charging operation is carried out via a novel multi-voltage network on
the vehicle side using a high-voltage DC/DC (HV-DC/DC) converter,
transforming the required 800 V input voltage of the charging station
to the lower 400 V system voltage of the BMW i3 research vehicle. The
HV-DC/DC system also gives the vehicle reverse compatibility, allowing
it to be charged at both old and future charging stations. A key
factor in ensuring reliable operation is secure communication between
the vehicle and the charging station. For this reason, standardisation
issues relating to interoperability are also being investigated and
submitted to standardisation bodies.

The Porsche research vehicle with a net battery capacity of approx.
90 kWh achieves a charging capacity of more than 400 kW, thereby
allowing charging times of less than three minutes for the first 100
km of range.