Porsche Uses SiC FETs in Modular Fast-Charging System Suitable for All EVs

October 01, 2018 by Paul Shepard

Porsche Engineering has announced a fast charging system comprising modular units in order to make the technology suitable for charge parks of different sizes. The modules used can also be changed depending on the nature of the grid and the visitor frequency. The fast charging system builds on the 800-Volt technology that is also offered by Porsche as part of its high-power charging solution.

The modular architecture of the new solution is designed to enhance flexibility when setting up a fast-charging station for electric cars.

The new chargers called FlexBoxes measure 120 x 120 x 130 cm and are essentially weather-proof housings which are meant to accommodate all the other components and these can be installed out of sight from customers. One example in which a FlexBox can be used is to cover the transformer in a charge parks where there is a connection to the medium-voltage grid. In the case of a transformer designed by Porsche, it is possible to fit the galvanic isolation inside instead of adding it to each individual charging pole, further reducing the space needed and the associated costs.

Another key component is what Porsche calls the PowerBox. Which converts the low-voltage alternating current received from the transformer station into the dc that is needed for fast-charging.

The PowerBox can be equipped with two sets of power electronics and can thus supply two charging points. It uses silicon carbide (SiC) modules, and the use of this material offers benefits like lower conduction, need for less space and minimal switching losses.

In the case of charging parks having a less powerful grid connection, the ChargeBox comprises in addition to power, a buffer storage battery. It is available as an entry-level model with a 70kWh battery and a 160kW charging station. For locations having more visitors, electric vehicles with higher charging capacities or as a subsequent retrofit, there is a fully equipped variant with 140kWh and two 160kW charging stations, combinable for 320kW.

All of these components can accommodate a distance of up to 200 meters between the transformer station and PowerBox and up to 100 meters between the PowerBox and the charging station.

Another component that is important, especially when it comes to high power charging is the CoolingBox. It comes with liquid cooling for the charging poles and power electronics. Each CoolingBox has enough space to accommodate two cooling units. Each cooling unit has the capability to cool multiple charging points under all operating conditions, according to Porsche. The CoolingBox may be installed at some distance from the charging stations as well.

For operators with limited space at the charge park, Porsche Engineering has developed the ComboBox, a power unit that integrates a cooling unit which is sufficient for one fast-charging point for electric cars.

Porsche says that when it comes to its forthcoming Taycan model which will feature advanced lithium-ion battery packs and 800V technology, it will be possible to get 400 kilometers of range by charging the vehicle for just 20 minutes. The company also has ambitious plans to install as many as 500 charging stations across North America by the end of 2019.