Research on Relay Protection Setting Method for Active Distribution Network

The proportion of distributed generation (DG) connected to distribution networks is constantly increasing. Traditional protection schemes are insufficiently adaptable to distributed generation, and manual setting or methods based on enumeration cannot meet the requirements of distribution network setting calculation. This paper first analyzes the influence mechanism of distributed generation connected to distribution networks and proposes a short-circuit current calculation method for active distribution networks. Then, current instantaneous protection and overcurrent protection are analyzed respectively to determine the setting calculation method. The basis for selecting the equivalent bus is obtained by establishing a method to find the extreme value of the short-circuit current function. Finally, a distribution network setting calculation case is used to verify the accuracy of the setting calculation method determination proposed in this paper and demonstrate the relay protection setting method for active distribution networks.