Protection technology principles for typical design of substation secondary system

The current differences in principles and schemes of relay protection system in substation design are inconvenient for operation, maintenance and management, and cannot be adapted to the requirements of developing modern power grid. Based on Typical Design for Power Transmissionand Transformation Projects, State Grid Corporation of China has completed Typical Design of Substation Secondary in Power Transmission and Transformation Projects. The application status of the protection equipment in 500 kV substation was introduced. The making process and the basis of the relational provisions and parameters for the protection equipment in Typical Design of Substation Secondary System were illustrated. In addition, some special functions with larger changes were analysed and explained, and some problems and recommendations which should be noticed on the implementation were proposed.