IEEE Draft Standard Technical Specifications of a DC Quick Charger for Use with Electric Vehicles

Direct Current Charging or DC Charging is a method of charging which facilitates rapid energy transfer from the electric grid to plug in vehicles. This method of charging allows significantly more current to be drawn by the vehicle vs. lower rated alternating current (AC) systems. A combination of vehicles which can accept high current DC charge, and the DC supply equipment which provides it has led to the use of terminology such as Fast Charging, Fast Charger, DC Charger, Quick Charger, etc.DC charging and AC charging vary by the location at which AC current is converted to DC current. For typical DC charging, the current is converted at the off board charger which is separate from the vehicle. For AC charging the current is converted inside the vehicle, by means of an on- board -charger. The location of the AC to DC conversion equipment, or converter, shapes the complexity of the equipment design. Regarding AC charging, as mentioned above, the conversion is on-board the vehicle. This allows the OEM designed systems to control the charging operation in its entirety. The on-board-charger (converter) and battery controller solution is under direct control of the vehicle manufacturer. For DC charging, an entirely new challenge for OEMs exists. The DC charger is now external to the vehicle and requires the vehicle engineers to control an external power device. For the reason of necessary interoperability, standards such as IEEE P2030.1.1 are provided to assist developers.