With the rapid development of modern distribution network and the access of distributed generation

the network structure is becoming increasingly complex. Frequent single-phase break faults have seriously affected equipment and personal safety and stable operation of the power system. However

with the development and application of the composite neutral grounding modes

the protection of single-phase break fault is facing new challenges. This paper proposes a protection method of single-phase break fault for distribution network considering the influence of neutral grounding modes. The characteristics of neutral voltage and sequence current are analyzed under normal operation and single-phase break fault with different grounding modes. Following this

the protection criterion based on neutral voltage and sequence current variation is constructed. The protection method of single-phase break fault for distribution network is proposed

which is applicable for various neutral grounding modes. Theoretical analysis and simulation results show that the protection method is less affected by system asymmetry

fault location and load distribution. The method has higher sensitivity

reliability and adaptability.