Fast charging systems, High Power Charging(HPC), are charging systems with which batteries of electric vehicles are charged quickly at maximum power. There are several fast charging systems that work with direct current. These are the Combined Charging System( CCS), Charge de Move( CHAdeMO) and Supercharger from Tesla.
Fast charging systems aim to shorten long charging times with High Power Charging (HPC) or Extreme Fast Charging (XFC). This goal is met by fast charging with an extremely high charging power. While the charging power for the CCS system is 22 kW for normal charging and 44 kW for AC fast charging, DC fast charging involves 170 kW and even a maximum of 350 kW charging power. This allows charging times to be dramatically reduced and batteries to be charged within a few minutes for about 100 km of driving.
CCS fast charging, for example, operates with a DC voltage of 850 V and a charging power of max. 350 kW. The resulting charging current is thus around 400 A. These values are exceeded several times over by the new Asian fast-charging system ChaoJi. ChaoJi is said to have a charging power of 900 kW, with a direct current of 600 A and a direct voltage of 1,500 V. This extremely high charging power is to be used for long-distance buses and trucks so that their batteries can be charged in a short time.
High charging currents of several hundred amperes are problematic for heating up the batteries, which could reach temperatures of up to 250 °C in a short time. Further problems are posed by the charging plug, which is the combo plug, and the charging cable, as this heats up at high currents and cannot be fitted with thick wire cross-sections due to excessive rigidity. They are then no longer manageable. Technical approaches to reducing battery temperature during fast charging are offered by Battery Thermal Management Systems( BTMS), and as far as the charging cables are concerned, charging cables with cooling could be used.
As far as wireless charging technology is concerned, and especially fast charging, the TH Deggendorf has developed a contactless inductive fast charging system with an energy transfer of 30 kW as part of a research project. This system is based on the standardized Chademo charging interface. Energy is transmitted at a frequency of 30 kHz.