Abstract: A photovoltaic power generation system includes: a plurality of units, each of the units being formed with a string, which is a series-connection body of a plurality of solar cell modules, or with a solar cell module; a plurality of connection cables to which the units are each connected such that the units are parallelly connected to each other; a junction box to which each end of the plurality of connection cables is connected; and a failure detection section that performs failure detection and outputs a detection result on a unit-by-unit basis, the failure detection section being located outside the junction box.