Research and Demonstration Application of Distribution Network Protection Adaptation

As the first line of defense for the safe and reliable operation of the power system, the relay protection device plays an important role in the operation of the power grid, and whether the protection device can play the maximum role depends largely on the accurate setting and configuration of the protection value. In terms of new active distribution networks, the extensive access of distributed new energy has changed the structure of the distribution network and the fault characteristics of the distribution network, making it impossible for traditional protection devices to accurately determine the fault section. At the same time, when the operation mode of the power grid changes, the existing protection value cannot adapt to the changed operation mode, so the protection value needs to be adjusted in time. In order to meet the needs of the intelligent development of the power grid, Huangshan Company has developed an adaptive relay protection value switching method, which can automatically select the corresponding value according to the change of operation mode and the size and direction of the current at the time of failure. It solves the drawbacks of untimely and error-prone manual switching of traditional fixed values, improves efficiency, and significantly improves the reliability of power supply in the distribution network.