VEHICLE GROUND FAULT DETECTION

A vehicle power system includes a traction battery, a non-isolated power converter, a current sensor that measures phase current input to the non-isolated power converter during charging of the traction battery with grid power, and a controller. The controller interrupts an electrical connection between the traction battery and a source of the grid power responsive to a magnitude of a 3rd harmonic component of the phase current exceeding a threshold value to prevent further charging of the traction battery.