Research On 20kV Area Protection System Based On GOOSE/SV Network

The automation equipment of the low voltage system of the traditional integrated automation substation mainly includes:the transformer low voltage side bus protection and the automatic switch device. The bus protection delay is long, which is easy to cause damage to the equipment; the existing automatic switch device has poor adaptability to the ring power supply network. Limited to the technical of the traditional integrated automation substation, it is difficult to solve these problems from the essence, the rapid development of digital substation provides a new method for these problems. Based on the platform of digital substation, this paper establishes a set of 20kV substation area protection system to solve the problems above.Firstly, the design of 20kV process layer network is carried out. The process layer network is the link of various intelligent modules in the station. The reliability and real-time performance determine the performance of various intelligent devices. This paper first introduces the types and characteristics of the process layer network communication message, SV message and GOOSE message on real-time precision is millisecond level; then analyze the real-time and reliability of the process layer network topology structure, determines the choice of double star network structure as the process layer network structure; finally formulate 20kV layer network configuration scheme. The scheme includes 20kV layer network traffic analysis, process layer network, switch configuration scheme.Through the traffic analysis, the conclusion that SV traffic accounts for 99% of the total network traffic is concluded. According to this conclusion, the network mode of GOOSE and SV co network is determined. The switch configuration scheme is determined by calculating the network delay and the number of the port number of the statistical intelligent devices.Secondly, the 20kV process layer network flow control scheme based on the static multicast is proposed. GOOSE and SV message use multicast in the network communication, without control will cause the device CPU overload and network crash. Three ways of network flow control are analyzed in this paper:GMRP dynamic multicast management, VLAN multicast management and static multicast management. According to the characteristics of 20kV process layer network, select the static multicast technology, and make the static multicast configuration scheme of 20kV process layer network switch.Finally, this paper designs the 20kV substation area protection system.20kV substation area protection system is composed of 20kV fast busbar protection and 20kV ring network automatic switch device. Based on the 20kV process layer network, design a set of 20kV substation area protection system.20kV fast busbar protection achieve removal of bus fault fastly; 20kV ring network automatic switch device set up 4 auto-switch modes suitable for the ring grid. Through the 20kV process layer network experiment,20kV fast busbar protection function experiments,20kV ring network automatic switch device function experiment, verify the performance of the network, the system logic functions meet the design requirements.