SOLAR CELL STRING ABNORMALITY DETECTION METHOD, ABNORMALITY DETECTION DEVICE, AND PHOTOVOLTAIC POWER GENERATION DEVICE

摘要

A controller (6) of a photovoltaic power generation device (1) monitors the midpoint voltage level (V(m)) of each solar cell string (2(m)) and, based on the midpoint voltage level (V(m)), detects the abnormality of a solar cell module (7(m, n)). When an abnormality occurs in one of a plurality of solar cell modules connected in series, only the voltage at both ends of the one of the solar cell modules becomes lower than the voltages at both ends of the other solar cell modules. The midpoint voltage level (V(m)) of the relevant solar cell string is largely shifted to the side of a polarity to which the solar cell module in which the abnormality has occurred is connected. A solar cell module abnormality can be detected more accurately than when terminal current is monitored.