EV Charging Modes
IEC 61851-1 defines four charging modes.
Mode 1 Mode 1 charging involves connecting an electric vehicle to an AC power network by plugging the standard plug of the EV charging cable assembly into a standard socket, thus charging the electric vehicle.
Mode 1 does not require a control pilot function, and the electrical connection does not need auxiliary contacts.
The charging parameters specified in IEC 61851-1 for Mode 1 must not exceed:
The charging parameters specified in IEC 61851-1 for Mode 1 must not exceed:
● 16A/250V, single-phase AC
● 16A/480V, three-phase AC
Mode 1 directly uses the residential power distribution network, so the maximum parameters in practical applications depend on the capacity regulations of the specific country's residential power distribution network.
Although Mode 1 does not require modifications to the existing residential power distribution network, making it convenient and flexible, the widespread use of Mode 1 charging could significantly increase the load on the power grid, impact grid stability, and pose fire hazards. Therefore, many countries directly prohibit Mode 1 charging (such as the United States, the United Kingdom, and Singapore), or impose additional restrictions like setting limits on charging current or charging time (such as in France, Denmark, and other continental European countries).
Mode 2
Mode 2 charging involves a charging cable assembly with a standard plug on one end, which is plugged into a standard socket to connect to the AC power network, and a connector on the other end (vehicle side). The charging cable assembly includes an in-cable control and protection device (IC-CPD or ICCB) in the middle.
The in-cable control box provides the control pilot function as specified by IEC 61851 and meets the electrical protection requirements of IEC 62752.
The Mode 2 charging cable assembly must have a control pilot function and provide protective grounding, requiring at least three auxiliary wires. Therefore, most mainstream single-phase AC charging ports have at least 5 pins (two pins for charging conductors, two for control pilot, and one for grounding protection). Three-phase AC charging ports typically have 7 pins (four pins for three-phase four-wire charging conductors, two for control pilot, and one for grounding protection). In many regions, three-phase and single-phase charging ports are interchangeable, using a 7-pin configuration, with two phase wires unused during single-phase charging. For more details, refer to my other article on standard charging ports for electric vehicles.
The charging parameters specified in IEC 61851-1 for Mode 2 must not exceed:
● 32A/250V, single-phase AC
● 32A/480V, three-phase AC
Mode 3
Mode 3 AC charging involves a charging station that is permanently connected to the AC power network, with the charging station providing the control pilot function.
The AC charging port on the vehicle side for Mode 3 is the same as in Mode 2.
Common specifications for Mode 3 AC charging stations include:
● 7.4kW (230V/32A, single-phase)
● 11kW (400V/16A, three-phase)
● 22kW (400V/32A, three-phase)
Mode 4
Mode 4 DC charging involves a charging station that is permanently connected to an AC or DC power network, with the charging station providing the control pilot function.