**5. Conclusions**

In this paper, the prestrike characteristics of a double-break VCB consisting of two 12 kV VIs in series under DC voltages had been experimentally analyzed. The following conclusions can be drawn.


double-break VCB on the prestrike characteristics, which may be caused by the asynchronous property of the mechanical actuators, the inhomogeneity of the inherent prestrike characteristics and the unequal voltage-sharing ratio of VIs in a double-break VCB.

**Author Contributions:** Y.G. (Yun Geng) and X.Y. contributed to the research idea and designed the experiments. Y.G. (Yun Geng) and J.D. worked on the data analysis and drafted the manuscript. X.L. and J.P. helped to do the experiments. Y.G. (Yingsan Geng), Z.L. and K.W. worked on editing and revising of the manuscript. All authors have read and approved the final manuscript.

**Funding:** This work was supported in part by the National Natural Science Foundation of China under Grant 51937009, Key Research and Development Program of Shaanxi (2019ZDLGY18-04), the Fundamental Research Funds for the Central Universities (xzy022019013).

**Conflicts of Interest:** The authors declare no conflict of interest.
