Ultra Fast Charging

When people are travelling, they want to charge their cars quickly. This increases the demand of ultra fast charging. There are many Fast chargers with a 350 kW capacity that can enable a Battery Electric Vehicle (BEV) to drive 200 km further by charging for only ten minutes. It is expected that supply and demand of these Fast chargers will increase highly in the next couple of years. Especially along the highway.

Design challenges with an Ultra Fast Charger – HPC (High power converter)

In order to charge quickly, more power is needed. Increasing power is easy, however, it is the battery that decides how quickly it can be charged. In practice this depends on the temperature of the battery – not too hot, not too cold – and on how much power the battery still has (battery state of charge - SOC). Fastned has a table where charging curves are shown. It is striking that most cars only accept max power when the battery is below 40% SOC. If the SOC is above 40%, the charging capacity decreases. If the SOC is above 80%, fast charging has no use at all. The BMW-i3 and Audi keep up the high charge lower over a long time and up to 80% SOC. Tesla recently introduced the first electric car (Model 3) to be able charge at up to 250 kW using V3 Superchargers. An owner tested the new V3 supercharging and according to his report the SOC increased from 9% to 90% in just 35 minutes! Initial charging power was 255 kW.

The cable and the plug are also determining factors for the maximum current. The default CCS2 cable can charge 200A maximum. Because most EV batteries have a voltage of 400V DC, this results in a maximum power of an average 80kW.
To increase the charging speed you need a cable that is more than 200A DC. These cables are usually liquid-cooled. For more about the cable please visit the Phoenix Contact website.

Concluding
Although the industry is consumed with high charge power rates, the charging speed in kW depends on the EV battery, the SOC of the EV battery and on the charging station with corresponding DC charging cable. What matters is the amount of km 's per hour that is charged in to the battery. Preferably over a wide SOC range of the battery. 

PRE charger Modules and Engineering Services
PRE Power Developers has developed the 25kW DC/DC charger module especially for Ultra Fast Chargers. The power of this module can be switched in series or in parallel up to 1000V. Chargers that already work with this module have a very high reliability and a very high up time.
PRE also offers design services. PRE has the knowledge to develop a complete charger that meets the highest standards and regulations.

Links:
Ultra Fast Charging Products
Ultra Fast Charging Engineering Services