In a 400 V three-phase AC power network the maximum usable charging power is limited to 22 kW (32 A) or 43 kW (63 A) due to the necessary mains fuses, among other things. Charging with direct current (DC) at special charging points is therefore favoured for the fast charging of powerful vehicle batteries.
Today, battery packs with voltages of around 400 V are usually charged at fast DC charging points. The typical charging power is a maximum of 50 kW, so it takes about 80 minutes to charge a battery for a travel distance of 400 km (Fig. 1). As the charge plugs currently offer a maximum continuous charge current of 200 A, the charging power possible with the present-day 400 V systems is at most 80 kW. At the present time, it is therefore hard to improve on a charge time of 50 minutes for a travel distance of 400 km.
The objective of charging an electric vehicle just like “filling up” a traditional car is of crucial importance to the development of the entire infrastructure in the field of e-mobility. Therefore, an increased voltage of 800–1000V is already being pursued to quickly deliver the same amount of power with the same current. From today's perspective, an increased charge current of 350A will be possible with future battery technology using liquid-cooled charge plugs. This means that an operating range of 400 km could be achieved with a charge voltage of 1000 V within about 11 minutes.