Research On The On-Site Protection Technology Using Wireless Access Technology In The Control Layer Of A Substation

As the pilot construction of the next generatio intelligent substation, the hierarchical protection system of transformer substation uses the decentralized, local allocation scheme and puts the relay protection equipment as close as possible to the primary equipment layout, therefore the on-site relay protection technology is appeared. The on-site relay protection focuses on the protection of single primary equipment, it can realize the backup protection by the time-matching of upper and lower levels protecetion. The physical distance between the gateway and relay protection equipments is enlarged which results in monitoring equipment being seriously interfered by the electromagnetism of primary equipment. In view of the situation, there is a more highly serious requirement for the channel reliability, flexibility and security of the network. With the layout of relay protection device gradually dispersing, it’s necessary to strengthen the communication between the relay protection equipment and monitoring equipment in order to improve the supervision and control of the equipment, timely adjust to the protection deblocking and blocking function according to the running state of the power grid, and examines abnormal equipments in time, etc.The distributed layout of relay protection device has become an inevitable trend, and the on-site relay protection technology has been applied in Hubei and other pilot programs. In the application process, the disadvantages of the protection equipment access network such as high pavement cost and low maintainment efficiency at the later running state are exposed. Aimming at above problems, this paper comes up with the on-site relay protection technology of wireless access, studies deeply the current automation system of the transformer substation and extracts the related network architecture and technical indicators. According to requirements of substation automation system, the feasible technology scheme is given about the reliability, real-time capability of the system,and the reliability and realt-time capability of the technology above given is tested in a substation. The feasibility of the technology scheme is demonstrated.In order to verify the performence of the whole network, the end of this paper conducts the experiment of one hundred points scale network and further illustates the feasibility of the on-site relay protection technology using wireless access.