Two terminal fault positioning based on travelling wave is a kind of effective and fast positioning technology of fault of high voltage cable and the reaching time to measure the fault travelling wave and calculating travelling wave is the two key issue to affect locating accuracy. First

a kind of non-contact fault voltage measurement sensor with variable gain

the gain adjustment reference curve is calculated and is used for instructing gain adjustment of sensor. Then

the feedback variational mode decomposition (WVD) is adopted in combination with Wigner-Ville distribution method to calculate high-frequency components of the faulty travelling wave and to calculate the maximum value of distribution curve of high-frequency component so to obtain the accurate reaching time of the faulty travelling waveform. PSCAD/EMTPC simulation method has the reaching time which can accurately determine faulty travelling waveform. Finally

the experimental verification is performed on one out of operated 110 kV cable. The result shows that the locating error is no more than 0.5%

which is more superior to the presently used methods. Both the theoretical and experimental results show that the developed new type of sensor and the selected FVMD and WVD method can quickly and effectively determine position of the faulty cable

which has guidance significance for the development of fast positioning and maintenance of the fault of the cable.