title: Understanding the Percolation Characteristics of Nonlinear Composite Dielectrics.
abstract: Nonlinear composite dielectrics can function as smart materials for stress control and field grading in all fields of electrical insulations. The percolation process is a significant issue of composite dielectrics. However, the classic percolation theory mainly deals with traditional composites in which the electrical parameters of both insulation matrix and conducting fillers are independent of the applied electric field. This paper measured the nonlinear V-I characteristics of ZnO microvaristors/silicone rubber composites with several filler concentrations around an estimated percolation threshold. For the comparison with the experiment, a new microstructural model is proposed to simulate the nonlinear conducting behavior of the composite dielectrics modified by metal oxide fillers, which is based on the Voronoi network and considers the breakdown feature of the insulation matrix for near percolated composites. Through both experiment and simulation, the interior conducting mechanism and percolation process of the nonlinear composites were presented and a specific percolation threshold was determined as 33%. This work has provided a solution to better understand the characteristics of nonlinear composite dielectrics.
authors.affiliation: State Key Lab of Power Systems, Department of Electrical Engineering, Tsinghua University, Beijing, 100084, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Yang
authors.affiliation: State Key Lab of Power Systems, Department of Electrical Engineering, Tsinghua University, Beijing, 100084, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Hu
authors.affiliation: State Key Lab of Power Systems, Department of Electrical Engineering, Tsinghua University, Beijing, 100084, China.
authors.forename: Shuiming
authors.initials: S
authors.lastname: Chen
authors.affiliation: State Key Lab of Power Systems, Department of Electrical Engineering, Tsinghua University, Beijing, 100084, China.
authors.forename: Jinliang
authors.initials: J
authors.lastname: He