Improved differential protection method for photovoltaic grid-connected lines based on model recognition

Abstract With the large-scale integration of photovoltaic (PV) power into new power systems, traditional relay protection mechanisms face numerous challenges such as difficulty in fault identification and issues with protection device malfunctions or failures. This paper addresses these challenges by studying a longitudinal differential protection method based on model recognition for grid-connected lines. Through theoretical analysis and simulation validation, the proposed method can accurately identify faults under transient response control post-fault, meeting the requirements for speed and adapting to actual PV operation conditions, thereby enhancing the reliability and stability of new power systems.