Photovoltaic power generation system and inverter, fault protection device and combiner box thereof

The utility model discloses a photovoltaic power generation system and an inverter, a fault protection device and a combiner box thereof, and relates to the technical field of photovoltaic power generation. The inverter includes: a plurality of power conversion units; each protection switch unit comprises a plurality of protection switches, each protection switch unit is suitable for correspondingly connecting one photovoltaic group string unit to one power conversion unit to form at least two photovoltaic group string branches, and the photovoltaic group string branches are suitable for being connected with one photovoltaic group string or two photovoltaic group strings connected in parallel. Under the condition that a common positive or common negative power conversion unit exists in the plurality of power conversion units, the protection switch unit corresponding to the common positive or common negative power conversion unit performs protection switch sharing when being connected with the corresponding ph