Advancing the reform of the energy structure and developing renewable energy has become the current boom. DC transmission technology is an effective means to solve the problems of new energy consumption and long -distance, large-scale power transmission. After the rapid development of DC transmission technology, a situa-tion where multiple types of line-commutated converter (LCC), voltage source converter (VSC), and line-commutated converter-voltage source converter (LCC-VSC) coexist have been formed. The diversification of topological structures leads to insufficient applicability of existing DC protection schemes. In addition, poor resistance to high resistance faults is the main problem of existing traveling wave protection. To improve the applicability and anti-interference ability of the traveling wave protection scheme, a single-ended traveling wave protection scheme based on elastic coefficient is proposed in this paper. First, the time-domain and frequency-domain expressions of the first traveling wave are deduced and the influence of the boundary element trans-fer function on it is analyzed. Subsequently, the elastic coefficient is introduced and fused to the first traveling wave. Finally, a protection scheme including a starting element, a fault identification element, and a fault pole selection element is proposed. The experimental results of various topologies (LCC, VSC, LCC-VSC) verify the reliability and scalability of the proposed protection scheme.
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