Abnormality diagnosis device, method therefor, and computer-readable medium

An abnormality diagnosis method for a photovoltaic power generation system which controls power generation using a plurality of subsystems each including a plurality of power generation modules being interconnected, comprising:

• reading out power generation output data from a power output data storage configured to store power generation output data representing a current and a voltage of electrical power generated by each of the subsystems according to sampling time;
• correcting, for each of the subsystems, at least the current out of the current and the voltage in the power generation output data to a current or a voltage corresponding to a standard insolation condition using insolation intensity data to generate insolation-corrected power generation data including a corrected current and either one of a corrected voltage or the voltage in the power generation output data;
• producing, for each of the subsystems, an approximation graph of the insolation-corrected power generation data and calculating a gradient of the approximation graph;
• and
• determining a subsystem for which the gradient satisfies a first threshold to be a subsystem including an abnormal module.

A non-transitory computer readable medium storing a computer program for a photovoltaic power generation system which controls power generation using a plurality of subsystems each including a plurality of power generation modules being interconnected, the computer program which, when executed by a computer, causes the computer to perform steps comprising:

• reading out power generation output data from a power output data storage configured to store power generation output data representing a current and a voltage of electrical power generated by each of the subsystems according to sampling time;
• correcting, for each of the subsystems, at least the current out of the current and the voltage in the power generation output data to a current or a voltage corresponding to a standard insolation condition using insolation intensity data to generate insolation-corrected power generation data including a corrected current and either one of a corrected voltage or the voltage in the power generation output data;
• producing, for each of the subsystems, an approximation graph of the insolation-corrected power generation data and calculating a gradient of the approximation graph;
• and
• determining a subsystem for which the gradient satisfies a first threshold to be a subsystem including an abnormal module.