Prof. Huajun Dong

Experience: 

Prof. Huajun Dong is a professor, doctoral supervisor, and Dean of the School of Computer and Communication at Dalian Jiaotong University, an evaluation expert for the National Natural Science Foundation, a review expert for the Transactions of China Electrotechnical Society, and a member of the Journal of East China Jiaotong University. His main interests of research cover the key technology of vacuum switches and the application technology of image processing. Prof. Dong was awarded the Outstanding Postdoctoral Fellow of Henan Province in 2013, the Outstanding Teacher of Dalian Jiaotong University in 2017, the Hundred-level Talent of the National Hundred and Thousand and Ten-Thousand Talent Project in 2018, and the Outstanding Teacher of Liaoning Province in 2020. He has obtained patents for calculating the position and velocity of vacuum switch contacts and a vacuum switch contact that can be used in a longitudinal magnetic field. 

The research projects he has undertaken over the past two years are as follows: 

(1)  Pinggao Group Co., Ltd.: Motion Characteristics Test of 252kV Circuit Breaker at High Speed, 300,000, 2021. 

(2) Pinggao Group Co., Ltd.: Simulation Research on Arc Characteristics of 550kV SF6/N2 Mixed Gas Disconnector, 500,000, 2020. 

(3) Tianjin Pinggao Intelligent Electric Co., Ltd.: Simulation Research on Arc Plasma Parameters of Vacuum Interrupter, 450,000, 2020. 

(4) Tianjin Pinggao Intelligent Electric Co., Ltd.: Sensitivity Analysis of Technical Parameters of 60Hz Vacuum Interrupter, 470,000, 2020.

Speech Title: Evolvement Law and Mechanism of Flow Field in Vacuum Switching Arc in Short-gap

Abstract: Research on the evolution law and mechanism of arc flow field in vacuum switch plays an important role in promoting the development and application of vacuum interrupter. The arc flow field characteristics of short gap vacuum switch is taken as the research object, and the flow light field information method is put forward combined with micro imaging system and micro lens array to study the arc root fission behavior on electrode surface and the micro geometric characteristics and motion characteristics of molten pool. Establishing the magnetic fluid motion model of short gap arc, analyzing the dynamic evolution process of arc motion and extinction of arc column and its influence on the recovery strength of vacuum gap medium, and mastering the spatial three-dimensional distribution of macro particles in arc column area and the quantitative analysis of eddy current migration motion characteristics; Establishing a multi-field fully coupled numerical model of airflow field, temperature field and electromagnetic field, and the influence of electromagnetic, thermal and structural shapes on arc characterization parameters is analyzed; Based on Labview, an accurate detection platform for motion parameters of the operating mechanism is established, so as to realize the reasonable coordination between the output characteristics of the mechanism and the demand of vacuum arc. The purpose of this project is to explore the characteristics of arc flow field of short gap vacuum switch from macro to micro by using modern experimental diagnosis and numerical simulation technology, to promote the application of vacuum switch in capacitor bank, no-load transformer and reactance switching, and to provide theoretical and experimental technical basis for the design of new vacuum interrupter.