Field Experience in Traveling-Wave Fault Locator Based Auto-Reclose Cancelling on a Hybrid Transmission Line

Short circuits might occur anywhere in the power grid, so high-speed fault clearing, and fault locating are significant to maintain grid stability, safety, and reliability. Since most faults are transient, the auto-reclose (AR) scheme is widely incorporated to lessen outage duration, avoid extensive outages, and improve grid stability. Meanwhile, a hybrid transmission line (HTL) integrating overhead line (OHL) and undersurface cable is utilised globally in geographically constrained situations. Protecting HTL with the traditional method would ban the use of the AR scheme due to the hardship of ensuring the fault location. Moreover, traveling-wave fault location (TWFL) technology has evolved from grid monitoring into practical use in protective relaying to improve fault locating function in the grid. In the case of the Sumatra- Bangka 150 kV interconnection, the geographical condition led to the use of HTL composed of overhead lines, underground cables, and undersea cables. Therefore, this paper investigates the performance and accuracy of the TWFL to allow the AR scheme on fault along the OHL according to actual fault records. The results show that the accuracy of the TWFL is satisfying, although its performance is affected by the non-homogenous material throughout the HTL.