Maloperation prevention for overcurrent protection in photovoltaic integration system under weather intermittency

Abstract

Non-fault situations in a photovoltaic (PV) integration system, such as solar irradiance fluctuations and intermittency, may be detected as faults by overcurrent-based protection and lead to an unnecessary network outage. Therefore, this paper proposes a maloperation prevention strategy for overcurrent protection based on multiple criteria to accurately distinguish between fault and non-fault states in the PV integration system and prevent the transient overcurrent from causing breaker trips. A fault diagnosis algorithm is proposed for determining the fault and disturbance states by analyzing current changes and their integration over a time delay. The results obtained from both PSCAD/EMTDC simulation and hardware-in-the-loop testing demonstrate the effectiveness of the proposed method in identifying network faults and disturbances, thereby showcasing its ability to provide reliable protection with robustness against weather intermittency. Compared with existing methods, the proposed method demonstrates superior performance in response time, applicability and implementation. These characteristics offer assurances for the dependable and efficient operation of PV integration systems.