Fault diagnosis method for sequentially switched parallel regulator

The invention provides a fault diagnosis method for a sequentially switched parallel regulator. The method comprises the following steps that the work state of the sequentially switched parallel regulator in a faultless condition is analyzed; a fault mode of the sequentially switched parallel regulator is obtained by analysis; a detection point is selected for the solar cell sub-array voltage corresponding to each shunting adjustment circuit, and a sampling frequency is selected; the time length of sampling data is selected, and covers the complete switching period of the solar cell sub-arrayvoltage; the solar cell sub-array voltage corresponding to each shunting adjustment circuit is sampled, and an adjusted level is searched for; according to the found adjustment level, fault diagnosisis carried out; and sampling and diagnosis in the next round is turned to. According to technical schemes of the invention, it is only required to add the detection quantity of the solar cell sub-array voltage to each shunting