1. Liao, R.J., Wang, K., Zhou, T.C., et al.: A method of evaluating thermal aging state of oil paper insulation by partial discharge factor vector. J. Electrotech. 25(09), 28–34 (2010). (in Chinese)
2. Zhou, T.C., Yang, L.J., Liao, R.J., et al.: Oil paper insulation aging diagnosis based on partial discharge factor vector and BP neural network. J. Electrotech. 25(10), 18–23 (2010). (in Chinese)
3. Li, J., Liao, R., Grzybowski, S., et al.: Oil-paper aging evaluation by fuzzy clustering and factor analysis to statistical parameters of partial discharges. IEEE Trans. Dielectr. Electr. Insul. 17(3), 756–763 (2010)
4. Zhang, J.W., Wang, M., Xie, H., et al.: Aging stage evaluation of oil paper insulation based on random forest. Electr. Meas. Instrum. 55(09), 121–125 (2018). (in Chinese)
5. Wang, M.: Study on Evaluation Method of Oil Paper Insulation Aging State of Power Transformer. China University of Mining and Technology, Beijing (2018).(in Chinese)