Photovoltaic Panel Fault Diagnosis Method for Grid-connected Households Based on Least-square Fitting Power Loss

Few researches are taken for the fault identification and diagnosis of household photovoltaic panel system. The power loss caused by common faults is analyzed by the simulation of household photovoltaic panel systems within a county, through summarizing the array mismatch of different capacity systems. 3-Sigma and box charts are used to identify abnormal household photovoltaic users based on daily output per unit capacity. For the identified abnormal household photovoltaic users, the smart meter data of the abnormal household photovoltaic users and the surrounding normal household photovoltaic users are extracted, the theoretical output value is estimated, and the power loss in the full time period is calculated. Based on the analysis of different faults, the least square method is used to fit, and the fault type is determined according to the fitting degree and the output under different light intensity conditions. Finally, the algorithm is verified by Simulink simulation in that county.