The Combined Charging System(CCS) is a charging system for electric vehicles specified by the Charging Interface Initiative(CharIN) and used in European charging stations. The CCS system was jointly developed by the German car manufacturers Volkswagen with Porsche and Audi, Daimler and BMW together with the American companies Chrysler, General Motors and Ford and some suppliers. The CCS system is suitable for battery charging of electric vehicles( EV) and hybrid electric vehicles( HEV).
The Combined Charging System is designed for normal charging and for fast charging. There are two variants: CCS1 for North America and CCS2 for the European Union. Simple charging uses single- phase alternating current, faster charging uses three-phasealternating current, and fast charging uses direct current. The CCS charging system operates with either alternating current or direct current. While normal charging is done via the European Type 2 charging plug, fast charging is done via the Combo plug, which has two additional contacts.
For fast charging with CCS2, the charging power is 200 kW. This value is to be increased to 350 kW with the CCSplus fast charging system. This means that the charging current is 350 A when the charging voltage is increased to 1,000 volts. Corresponding charging currents would inevitably lead to higher heating of the charging cable and charging plug. To reduce the power loss, the plug contacts are optimized, the cable cross-section is increased and the heat generated is dissipated via the charging cable by heat conduction with subsequent convection.
The charging process is monitored by a charging control logic. There are two contacts: the Control Pilot( CP) and the Proximity Pilot( PP). The control method for AC charging uses pulse width modulation( PWM) and power line communication( PLC). The latter is used for faster AC charging and for fast charging. With the CCS system, the cost of charging can also be debited from the vehicle user's account or paid in cash. For this purpose, there is the Plug-and-Charge( PnC) mode of operation with which confidentiality is ensured.
The entire CCS charging system consists of the charging station, the charging cable, the charging plug and the charging infrastructure, and in CCS2 uses the ISO 15118protocol for communication and control functions.