Reliability evaluation of centralized protection system in smart substation considering impact of communication message

The impact of communication message has not yet been effectively considered in the reliability assessment of the centralized protection system in smart substations. To address this issue, first, a method to evaluate the reliability of communication messages was proposed by analyzing the transmission mechanism of the communication message. Subsequently, based on the centralized protection system in D2-1-type smart substations, contrastive analysis focusing on the impact of messages on protection reliability under different networking modes and protection strategies was carried out. Finally, virtual local area network (VLAN) was applied to demonstrate its capability to improve the reliability of protective messages. The result shows that, the distributed protection is subject to the message reliability, whereas the centralized protection is not apparently affected by the message reliability. The reliability of protection systems is also impacted by different networking modes, and VLAN is conducive to improving the protection system reliability.