The SAE AC charging socket (SAE J1772) is the standard interface for charging electric vehicles in North America. Its working principle covers electrical connection, communication protocol and safety protection, ensuring the safety and efficiency of the charging process.

1. Electrical connection

l Power input: The socket is connected to the AC power supply (120V or 240V) through a cable to provide power for electric vehicles.

l Plug and socket connection: After the charging plug is inserted into the vehicle charging port, an electrical connection is established through the internal conductive terminals (L1, L2, Neutral, Ground).

² L1 and L2: Transmit AC power (single-phase or two-phase).

² Neutral: Provide current loop.

² Ground: Ensure that the equipment is grounded to ensure safety.

2. Communication and control

l Control pilot circuit (Pilot Signal):

² The charging socket communicates with the vehicle through the control pilot circuit to confirm the charging status and requirements.

² The vehicle transmits the maximum charging current information to the charging device by changing the duty cycle of the pilot signal.

l ** proximity detection**:

² After the plug is inserted into the vehicle, the socket detects the connection status and starts charging preparation.

² When the plug is pulled out, charging stops immediately to ensure safety.

3. Charging process

l Initial handshake:

After the plug is inserted, the vehicle communicates with the charging device to confirm whether the voltage, current and other parameters match.

l Charging start:

After confirmation, the charging device closes the internal relay and starts power supply.

l Charging monitoring:

During the charging process, the vehicle and the charging device continuously monitor the current, voltage and temperature to ensure safety.

l Charging end:

When the battery is full or the user stops manually, the charging device disconnects the power supply and ends the charging.

4. Safety protection mechanism

l Overcurrent protection: Prevent the current from exceeding the rated value and damaging the device or vehicle.

l Overvoltage protection: Prevent voltage abnormality and ensure battery safety.

l Overheat protection: Monitor temperature to prevent danger caused by overheating.

l Ground fault protection: Detect leakage and cut off the power supply in time.

l Mechanical locking: Automatically lock after the plug is inserted to prevent accidental detachment.

5. Charging Mode

l Level 1 charging:

Using 120V household power supply, the charging speed is slower and suitable for nighttime charging.

l Level 2 charging:

Using 240V power supply, the charging speed is faster and suitable for home, public charging stations and workplaces.

The SAE AC charging socket ensures a safe and reliable charging process through electrical connection, communication protocol and safety protection mechanism. Its standardized design makes it widely applicable to electric vehicles in the North American market and meets the charging needs of different scenarios.