A novel fault location method by tower based on traveling wave time-frequency analysis

Fault location based on time-frequency analysis highly relies on the reliability of natural frequency method. A novel traveling wave fault location by tower based on time-frequency analysis is proposed for improving the fault location reliability and accuracy. First, the fault signals on both sides are analyzed and the natural frequencies are got and the initial fault point is acquired by using improved natural frequencies method. Then, the signal is analyzed by wavelet tools in time-domain. The time of reflection traveling wave from fault point to bus is calculated using the initial fault location result. Finally, the fault is located by the ratio of time spacing between the initial and the reflection wave on both sides. Simulations in EMTP combined with MATLAB show that, the proposed method improves the stability of natural frequency method for time-domain analysis, the error of fault location by tower is less than 400 meters for 400 kilometers line, and it can tolerate transition resistance up to 350 Ω. At the same time, the fault location results will not change when the line length varies 3 kilometers.