Optimal Traveling-Wave Fault Locator Deployment and Performance Assessment: A Dominion Energy Case Study

Over the past decade, Dominion Energy Virginia has successfully deployed traveling-wave fault locators (TWFLs) on its 500 kV system, which have demonstrated excellent results in locating faults. Encouraged by the result, we began to explore the potential to expand traveling-wave fault locator installation across the rest of Dominion Energy's transmission system, which includes substations operating at $230 \text{kV}, 138 \text{kV}, 115 \text{kV}$, and 69 kV. However, with more than 400 substations operating at these voltages, location selection is challenging. This paper presents an analytical approach to identifying the minimum number of fault locators required to achieve comprehensive system coverage and how to strategically determine their optimal locations to enhance cost effectiveness. Installation priority is based upon multiple factors including line length, fault history, connected customers, line homogeneity, and the capability of softwarebased methods to indirectly monitor multiple lines. This process is outlined in detail to provide others with the ability to replicate the study with a different power system. This paper also evaluates various traveling-wave-based products and develops a monitoring strategy to guide Dominion's future hardware selection and installation. A series of test scenarios with frequency-dependent line models were created for hardware-in-the-loop (HIL) simulation and testing using a real-time electromagnetic transient power system simulator.