Examination of fault detection technique in PV systems

Inhalt:
We present a measurement system for detecting failures in photovoltaic (PV) systems and explain how to detect a reduction in output by using measured data. We first investigated changes in the power value and the current value when a failure occurred in order to compare the sensitivity of a string measurement system and a power conversion system (PCS) measurement system in detecting the reduction in output due to failure. Next, we examined ways of detecting a failure. Comparing the current between strings was effective for detecting failures without any influence from environmental factors, but the detection is difficult if a failure occurs in multiple strings. Then, we tried to improve the accuracy of failure detection by combining performance ratio (PR) diagnostic method. We confirmed from the results that more failure patterns can be detected.