A fault locating method for PV arrays based on improved voltage sensor placement

Abstract

Solar photovoltaic (PV) power generation has been widely used because of its environment-friendly advantages. However, operational faults in PV arrays have always been one of the critical factors affecting the PV system’s power-generation efficiency and life cycle. This paper proposes a fault locating strategy, which does not need the current sensor in every PV string and can also minimize the number of voltage sensors between strings, to accurately locate the faulty PV modules in a PV array. A variety of faults including open circuit, short circuit, degradation and partial shading faults are considered, and a universal method is proposed in this paper to locate the faulty modules under these faults. In this method, the voltage sensors are deployed through differentiating the parity of the number of strings for the PV array, while the fault locating rules are formulated under each of the afore-mentioned faults, respectively. Compared with existing fault locating methods, the proposed locating technique is shown to be effective in the application to PV arrays with any size and capacity, and it can accurately locate each faulty module for those faults, especially for degradation and partial shading faults. Thus, it is helpful in PV array dynamic reconfiguration and maintenance cost reduction.