Analysis of Relay Protection Fault Propagation Mechanism and Attack Detection Method Under Cyber Attack

With the continuous development of new power system, the innovative application of information and communication technology not only promotes the intelligent evolution of power grid, but also attracts much attention on its network security. As the first line of defense of power system, relay protection device is widely used in power system. However, in the digital communication scene of smart substation, hackers can take advantage of the loopholes in the communication protocol of smart substation to tamper with the protection setting value, switch the setting value area, and throw back the soft board, which will affect the correct action of the protection device, lead to misoperation or refusal of protection, and affect the safe and stable operation of power system. In this paper, the fault propagation mechanism of relay protection under cyber attack is analyzed and studied, and the cyber attack detection method for protection devices is studied, which provides technical reference for improving the network security protection ability of relay protection business in power system.