To ensure their sound and continuous operation to the greatest extent

VSC-based DC girds have extremely stringent requirements for transmission line relay protection. In terms of guaranteeing their reliability

accurate identification of lightning strikes on DC transmission lines is one of the urgent key problems to be solved. An effective ultra-high-speed identification scheme of lightning strikes suitable for the VSC-based DC grid is proposed in this paper. First

an 1-mode reverse voltage traveling wave (RVTW) is constructed applying the pole-mode transformation theory. Next

fault traveling wave propagation characteristics along the DC transmission line are analyzed in depth utilizing Peterson's law. Then

differences of time-frequency electromagnetic transient characteristics of 1-mode RVTWs between disturbances and faults caused by lightning strikes are distinguished in detail by means of the classical wavelet transformation multi-resolution analysis theory. Finally

extensive simulations are carried out to evaluate the performance of the proposed identification scheme

and by which its excellent rapidity

reliability and robustness are validated.