The invention discloses a device and method for detecting faults of a
solar power generation
system. The
solar power generation
system comprises a plurality of
solar cell panel set strings and a
photovoltaic inverter. The device comprises a plurality of fault detecting units, a current converging device, a
control system and an auxiliary power source. Each fault detecting unit comprises a
control switch, the input ends of the fault detecting units are connected with the
solar cell panel set strings respectively, the output ends of the fault detecting units are connected with the input end of the current converging device, and the fault detecting units are used for detecting the relevant parameters of the
solar cell panel set strings, wherein the relevant parameters comprise the working
voltage and the working current or the open-circuit
voltage and the short-circuit current. The current converging device is used for collecting the direct currents output by the fault detecting units. The
control system is connected with the fault detecting units, and is used for comparing the relevant parameters with the history parameters of each solar
cell panel set string, analyzing the fault situation and controlling the on-off state of the control switches according to the fault situation. The auxiliary power source is used for supplying
electricity to the fault detecting units and the
control system. The device can directly detect the open-circuit
voltage and the short-circuit current, and a fuse is prevented from being replaced.