An MPPT-based sensorless line-line and line-ground fault detection technique for pv systems

Globally, almost all PV installations are deployed with maximum power point tracking (MPPT) technique to extract the maximum available power output. However, in the case of an electrically faulty PV arrays, the MPPT operation rapidly optimizes the fault current magnitudes to significantly low values that enforce line-line (LL) and line-ground (LG) faults to remain undetected in the system for longer time periods. Therefore, this paper proposes a sensorless, simple tracking technology to detect any LL/LG faults in a PV array by utilizing MPPT itself. The proposed technique exploits the uniqueness of the rightmost power peak (RPP) in the output characteristics of the PV array to detect LL/LG faults. For implementation, the globally used perturb & observe (P&O) MPPT algorithm is deployed to track the RPP. Experimental results reveal that the proposed methodology is well efficient to detect any LL/LG faults in PV arrays irrespective of the level of mismatch, system type, and the system rating. In addition, faults occurring in low irradiance levels and partial shading conditions (PSCs) can also be detected with incredible accuracy. Furthermore, the proposed technique is proficient to distinguish LL/LG faults from PSCs and temperature variations of a PV array in real-time environment. The merits of the proposed concept are its scalability, simplicity, and practical fitness.