Devices and techniques for detecting faults (e.g., ground faults) in photovoltaic (PV) systems are provided. A fault-detection impedance component may be included in a PV system on the path to equipment ground. The PV system may determine whether a ground fault exists based, at least in part, on a measured impedance between a conductor of the PV system and a ground node of the PV system, and on a reference impedance. When it is determined that a ground fault exists in the PV system, action may be taken to mitigate the ground fault.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with government support under Grant Nos. DE-EE0006035.000 and DE-EE0006035-005 awarded by the Department of Energy. The government has certain rights in this invention.