In the context of electric vehicles, charging plugs are plugs that are connected to charging cables and provide for the connection of the charging station or the wall charging station with the electric car. Since the technical framework conditions and requirements in Europe, the USA and Japan are very different, there are different charging plugs for normal charging via single- phase alternating current, faster charging via three-phase alternatingcurrent and special charging plugs for the fast charging systems.
As for the framework, the European power grid is three-phase, whereas the U.S. has a single-phase AC grid.
European charging plugs
Europe uses different charging plugs than the U.S., Japan and China. Europe uses the IEC 62196-2 standard specified by the International Electrotechnical Commission(IEC) with the type designation Type 2, known as the Mennekes plug. The standard specifies the charging plug and the charging modes of the charging station. Type 2 is suitable as a charging plug for the low- voltage and three-phase mains. It is also part of the combination plug, the combo plug, for DC charging of fast charging systems. In addition to the aforementioned Type 2 charging plug, there are other charging plugs developed by various electric car and plug manufacturers.
The European charging plug according to IEC 62196-2 is a 7- pin plug with three phases( L1, L2, L3), neutral conductor (N) and protective conductor( PE), as well as the two signal conductors Control Pilot( CP) and Proximity Pilot( PP). The connection for the ground conductor is located centrally in the middle of the connector. One side of the plug is flattened to prevent it from twisting. The charging plug, which is comparable in size to the familiar 16 A plugs for three-phase current( CEE plugs), is designed for both single-phase current at 230 V and three-phase current at 400 V.
The VDE has specified charging currents of 16 A, 32 A and 63 A for charging plugs for single-phase current and three-phase current. This corresponds to outputs of 3.7 kW, 7.4 kW and 14.5 kW in the 230 V network, and outputs of 11.0 kW, 22.1 kW and 43.5 kW in the 400 V network. The specifications according to IEC 62196-2 exceed these limits and specify a maximum charging current of 250 A for alternating current. For DC charging, the max. charging current is 400 A DC.
In addition to the charging plug mentioned above, there is also the combined combo charging plug for AC and DC for fast charging with DC high for charging mode 4. As far as other countries are concerned, the charging plug used in the USA is the five-pin Type 1 according to SAE J1772, which is also covered in IEC 62196-1. China has specified the plug according to the Chinese GB/T standard.
Functions of the charging plug
The advanced functionalities of the charging plug include a communication line between the charging station and the electric car, through which the charging status can be controlled and the electricity can be billed. The two signal lines are for the pilot contact, Control Pilot (CP), and the proximity switch, Proximity Pilot (PP). Via the pilot contact, the electric vehicle sends a signal to the charging station, indicating that charging is enabled. Via the PP contact, the charging current is limited according to the conductor cross-section to avoid overloading the charging cable. Other functions include an immobilizer, mechanical and electrical protection, as well as fault current, overload and component protection.
The charging plug used in the USA and Japan was developed by the Society of Automotive Engineers (SAE) and standardized under J1772. It is designed for single-phase current of 240 V and 70 A. Like the charging plug standardized in Europe, it has two signal lines for communication with the vehicle. Another charging plug used in China and India is the one for the GB/T charging system. It is a plug for single-phase AC voltage and for three-phase current. Like the charging plug for the CCS charging system, it has seven contacts for the three phases (L1, L2, L3), the neutral conductor (N) and the protective conductor (PE), and for the control signals Control Pilot (CP) and Proximity Pilot (PP). The transmittable charging powers are 11 kW, 22 kW and 43 kW.