High Frequency Component-Based Pilot Protection for Photovoltaic Station Collection Line

The output current phase of photovoltaic power generation unit is affected by inverter control, and photovoltaic power generation unit presents weak feedback characteristics, resulting in the current differential protection and pilot protection of collection line in photovoltaic station may malfunction. This paper analyzes the fault high-frequency additional network of the collection line of photovoltaic station, and proposes the high frequency component-based pilot protection. Based on the different relationship between the two terminal compensation voltage during the internal and external faults, the internal and external fault identification criteria are constructed. The proposed protection scheme has strong anti-fault resistance ability, fast action, low requirements for double terminal data synchronization, and is not affected by the inverter control strategy. The test results show that the protection scheme can accurately identify different types of internal and external faults, and has strong anti-noise interference ability.