Fault Location in Solar Farms

Abstract

Power delivery interruption and catastrophic failures are some of the potential consequences of undetected faults in photovoltaic (PV) arrays. A voltage protection scheme with the minimum number of sensors which is capable of detecting, classifying, and locating line-to-line (intrastring and cross string), line-to-ground, and open-circuit faults in a utility-scale PV array is proposed in this article. The proposed protection scheme consists of three steps. In the first stage, by a simple and efficient algorithm occurrence of any disturbance in the system is detected using some voltage sensors. At this stage, faulty strings in the PV array are also identified. In the second step, using a new least squares-based method, fault and shading conditions are discriminated from each other. Finally, in the third step, the faults inside the faulty string are located using a new method based on multiclass artificial neural networks. Fault location methods that have been developed so far require a large number of sensors or additional equipment for the exact location of faulty modules inside the fault string, but in the proposed method, only one sensor is used per string for fault localization. The proposed scheme for detection and location of faults is evaluated by simulating a typical system in different conditions.