Abstract:At present, substations lack a reliable and effective monitoring method for the connection status of outlet pressing plates in secondary circuits, making it difficult to guide relay protection operators to detect such secondary circuit defects in a timely manner. Existing schemes sense the pressing plate contacts through sensors and other means to judge whether the pressing plate is switched on, which can only indirectly confirm the pressing plate status in principle and lead to unreliable identification results. This paper studies a self-extensible intelligent sensing technology for relay protection pressing plates, which can realize real-time detection of pressing plate status and support bidirectional communication with the relay protection information system. For the acquisition of hard pressing plates at the substation side, mature and reliable protection devices and intelligent terminal devices are adopted, while the public and mature IEC 61850 standard and generic object oriented substation event (GOOSE) communication technology are used for data uploading, ensuring the reliability of data transmission and complying with network security protection requirements. The proposed scheme is simple, feasible, economical and practical. It adopts self-acquisition of hard pressing plates and constructs a data transmission scheme based on the existing data communication network without building an independent system, realizing intelligent convergence access and functional expansion. The feasibility and effectiveness of the scheme are verified through pilot substation applications. It can prevent incorrect operation events of relay protection caused by mis-switching of hard pressing plates, improve the operation risk identification and active defense capability of the first line of defense of the power grid, and enhance the security of power grid operation.