Fault analysis of solar photovoltaic penetrated distribution systems including overcurrent relays in presence of fluctuations

Intermittence from solar photovoltaic (PV) source can deteriorate overcurrent relays (OCRs) response to fault. This paper proposes a method for fault analysis with OCRs consideration to discuss relays faults currents fluctuations in time against PV fluctuations. The simulated PV fluctuations are short time dynamic high and low irradiations fluctuations and PV connection and disconnection based PV-dominated feeders. Two distribution systems (DSs) based accurate PV systems are modeled separately with and without Battery Energy Storage System (BESS) for the purpose of proposed method. Series and parallels PV modules are arranged to model accurate 6.5 kV PV farm power. Two level three-phase voltage source inverter (VSI), DC-DC boost converter and LCL filter are applied for each PV system. Precise detailed control strategies are implemented in PSCAD software. This paper proposed method complies with congestion which is frequently avoided in literature. The results discussions based proposed method clarified PV fluctuations scenarios impacts on OCRs dynamic fault currents profiles in presence and absence of BESS and clearly revealed and argued related important findings. In addition, OCRs performance is shortly analyzed based particle swarm optimization (PSO) algorithm efficiently coded in Matlab. The obtained results could be very profitable to power system relaying operators to handle protection challenges with PV power fluctuations.