Vertical Protection Technology for 220 kV Transmission Lines Based on Optical Fiber Communication

Longitudinal protection is the core technology for achieving rapid fault removal within the transmission system. The performance of communication channels directly affects the timeliness of protection actions and the accuracy of criteria. This paper analyzes the technical requirements of vertical protection for 220 kV transmission lines in terms of high-speed communication, anti-interference capability and data integrity. It studies the optical fiber communication channel constructed based on GOOSE message structure, SDH/OTN transmission platform and CRC error control mechanism, and proposes supporting technical paths such as photoelectric isolation, automatic switching of primary and backup links and virtual channel packaging. The aim is to achieve rapid interaction of differential values and precise response of protection actions in the optical fiber communication environment, adapt to the operational characteristics of multi-source interference, high-speed fault propagation and low fault tolerance error in high-voltage transmission scenarios, and construct a 220 kV transmission line longitudinal protection technology system with high reliability and strong robustness.