A method for leakage current compensation in a photovoltaic system includes determining a reference current flowing from at least one current-carrying line under voltage via a capacitor to earth, and generating a compensation current, having a phase and a frequency of the reference current, and having an amplitude adjusted by a negative scaling factor based on the reference current. The method further includes determining a current sum using a differential current sensor for at least a portion thereof, wherein the addends of the current sum are the currents through a complete set of current-carrying lines and the compensation current, minimizing the determined current sum by adjusting the scaling factor, and routing the compensation current through at least one other differential current sensor, such that the compensation current compensates a leakage current component of a differential current monitored by the other differential current sensor. A related device and system is also disclosed.