Study of joint temporal-spatial distribution of array output for large-scale photovoltaic plant and its fault diagnosis application

Abstract

The temporal-spatial distribution of photovoltaic (PV) array output in large-scale PV plant has following features: (i) In the DC (direct current) side of PV plant, the outputs from different arrays display a substantial correlation with each other. (ii) The dynamic difference for a PV array is covered by the random fluctuation of PV output. (iii) It is difficult to explain the occurrence and evolution process of PV faults with operation data only. Currently, most fault diagnosis methods for the PV arrays do not take advantage of the temporal-spatial distribution information contained in the operation data. To solve these above problem, a new fault diagnosis method using the spatio-temporal distribution characteristics of photovoltaic array output is proposed. Here, the temporal fluctuation and spatial distribution characteristics of PV array output under different fault conditions were analyzed. The spatio-temporal composite function is constructed, and then used to set fuzzy rules for fault diagnosis of the PV array. Finally, an example is used to verify the effectiveness of the proposed method, and the results show that the method can describe the characters of spatial and temporal distribution of PV output under faults conditions, and it can effectively classify different faults.