**Ming Zhang, Rumeng Wang, Lee Li and Yunpeng Jiang \***

International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics, State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical & Electronic Engineering, Huazhong University of Science & Technology, Wuhan 430074, China;

zhangming@hust.edu.cn (M.Z.); wangrumeng@hust.edu.cn (R.W.); leeli@hust.edu.cn (L.L.)

**\*** Correspondence: jiangyunpeng@hust.edu.cn

Received: 19 July 2018; Accepted: 28 August 2018; Published: 25 September 2018

**Abstract:** The characteristics of contamination on the insulation medium surface play an important role in the surface flashover, especially size distribution of contaminated particles. After measuring the size of contaminated particles on the porcelain insulator surface, obvious size distribution characteristics of particles were found. To study the reason for these statistical characteristics, the movement of particles was analyzed in detail combining with fluid mechanics and collision dynamics. Furthermore, an adhesion model was established in this paper. In addition, the influences of different factors on the adhesion were studied. The results showed that the size of adhered particles on the porcelain insulator surface was easy to focus on a specific range, and the influences of relative humidity and wind speed were remarkable. However, the influences of electric field type, electric field strength, and aerodynamic shape were relatively weak. This research was significant and valuable to the study of artificial contamination simulation experiments, and the influence of particles size distribution on pollution flashover.

**Keywords:** particle size; distribution characteristics; contaminated particle; porcelain insulator; adhesion simulation model
