Method and System for Controlling On-Board Battery Charger of Electric Vehicle to Accommodate Transients in Supply Voltage

A method for charging a traction battery of an electric vehicle, comprising:

• receiving, by an on-board battery charger (OBC) of the electric vehicle, AC electrical power from a charge station and outputting, by the OBC, a DC output current for charging the traction battery;
• detecting transients in the AC electrical power while the OBC is receiving the AC electrical power from the charge station and outputting the DC output current;
• controlling the OBC, while the transients are present, to stop processing the AC electrical power from the charge station and to reduce the DC output current;
• and
• controlling the OBC, at a zero-crossing event of the AC electrical power after the transients have passed, to resume processing the AC electrical power from the charge station and to increase the DC output current.

A system for charging a traction battery of an electric vehicle, comprising:

• an on-board charger (OBC) having a power factor corrector (PFC), a DC/DC converter, and a DC link capacitor disposed between the PFC and the DC/DC converter, wherein the PFC is to receive an AC mains voltage from a charge station, the DC link capacitor is to be charged by the PFC to a DC voltage setpoint, and the DC/DC converter is to receive DC electrical power from the DC link capacitor to output a DC output current at a DC current setpoint for charging the traction battery;
• a controller configured to detect voltage transients in the AC mains voltage while the PFC is receiving the AC mains voltage, the DC link capacitor is charged to the DC voltage setpoint, and the DC/DC converter is outputting the DC output current at the DC current setpoint;
• and
• the controller further configured to control the OBC, in response to detecting voltage transients in the AC mains voltage, to stop operation of the PFC and reduce the DC output current whereby the DC link capacitor discharges from the DC voltage setpoint and then to resume operation of the PFC at a zero-crossing event of the AC mains voltage after the voltage transients have passed to thereby recharge the DC link capacitor back to the DC voltage setpoint and to increase the DC output current back to the DC current setpoint.