• Establishing a DLR-IIDG coupling framework for active distribution networks. • Combining IIDG output regulation with line thermal constraints. • Quantitatively analyzing protection impact mechanisms under DLR regulation. • Proposing an amplitude–phase compensated differential protection scheme. • Enhancing renewable utilization while ensuring line thermal safety. With the massive access of inverter-interfaced distributed generator (IIDG), the new active distribution network is facing problems such as the inability to effectively utilize new energy and the lack of adaptability of protection schemes. To address these issues, dynamic line rating (DLR) technology is introduced to regulate IIDG output based on real-time environmental data collected by the intelligent distribution network system. Then, considering the problems of protection misoperation and rejection caused by the adjustment of IIDG output, the amplitude and phase compensation according to the measured current on both sides of the line is proposed. Combined with the dynamically adjusted braking coefficient, an improved ratio braking current differential protection scheme for active distribution network with DLR technology is formed to ensure the correct operation of the protection when the external environmental conditions change and adaptively reshape the operating regions of the differential protection. Finally, the simulation model is built on PSCAD / EMTDC, and the results confirm the effectiveness of the proposed scheme for active distribution networks with DLR integration.
Dai et al. (Sun,) studied this question.