278 / 2022-03-15 00:14:05

The impulse voltage response of ZnO/SiR composites

nonlinear conductivity,ZnO/SiR composites,impulse voltage

The polymer matrix doped with ZnO microvaristors show similar nonlinear conductivity characteristic to the ZnO varistors, which is promising to be used in the insulation of power apparatus as function materials. It is possible that the power equipment would suffer the transient process during the operation, but few study focused on the response of ZnO/SiR composites under these conditions. This study prepared ZnO/SiR samples with different filler volumes for the impulse voltage test and the responses under 1.2/50µs impulse voltage was obtained. It is found that there are two main elements contributed to the overall response of composites under such transient process, one is the capacitive current component caused by charge relaxation of Schottky Barrier on the grain boundary of ZnO microvaristors, another is the nonlinear resistance current components of Schottky Barriers. Under the low amplitude impulse voltage, the composites showed the capacitive current dominated response, and when the amplitude of the impulse voltage was enough high, the composites showed impedance current dominated response.