Thomas F. Papallo

Leakage current discrimination and masking from upstream ground fault protection devices during electric vehicle charging

An integrated ground fault protection method inside a plug-in electric vehicle charger is proposed to address the potential interaction of leakage current produced by electric vehicles or plug-in hybrid electric vehicles and upstream ground fault protection devices. This method incorporates the ability to determine the amount of capacitive leakage current generated from a vehicle and the actual ground fault current present utilizing the measured residual current and line voltage. With the determined capacitive leakage current and other known elements, appropriate leakage current masking can be applied to prevent nuisance tripping of upstream ground fault protection devices and provide lower trip thresholds in the electric vehicle charging industry.