Analysis and research on the sensitivity of current protection based on the planning and design of distribution networks

The safe and reliable operation of a distribution network (DN) is closely related to the development of national economy and the improvement of people's living standards. At present, the design principle of a distribution network is still based on a primary system and primary equipment, without considering the relay protection on the secondary side, which is an important guarantee for the safe and reliable operation of a power grid. The authors theoretically proved the influence of network structures on the main protection (instantaneous overcurrent protection and time‐delay instantaneous overcurrent protection) of conventional stage‐type current protection, and main influencing factors are analysed and verified in an example. The result shows that reasonable planning and design are an important premise for overcurrent protection to meet sensitivity requirements, and it shows a theoretical and practical guiding significance for the planning of a distribution network.