影响碳化硅防晕层电学性质的因素研究

在系统研究碳化硅(SiC)防晕涂层非线性导电特性影响因素的基础上,提出了提高发电机定子线圈端部防晕涂层起晕电压相应的调控技术。随SiC微粉含量的提高和漆含量的降低,SiC防晕涂层的表面电阻率下降,非线性系数提高,并当SiC微粉的含量超过某一临界值后,防晕漆的电阻特性接近于SiC本身的性质而趋于稳定,可有效改善生产工艺的稳定性;随层数的增多,SiC防晕涂层表面电阻率降低,非线性系数增大,且利用不同的SiC微粉,再辅以涂层层数变化以调控防晕涂层的表面电阻率,可获得更大的调控范围,完全可满足多级防晕结构的要求。

Research of Control Conduction Nonlinearity of Silicon Carbide Stress-grading Coating

In order to incease the discharge inception voltage of silicon carbide(SiC)stress-grading coating,the influencing factors on conduction nonlinearity of SiC stress-grading coating were systematacially studied,and the relevant control technology was put forward.The study indicates that:with the increase of SiC powder content in the coating,the surface resistivity of SiC stress-grading coating decreases,but the non-linear coefficient increases;when the content of SiC powder surpasses a certain critical value,the conduction nonlinearity of the anti-corona lacquer presentes a similar character of SiC and become stable,which can greatly improve the stability of the actual production process.With the increase of the coating numbers,the surface resistivity of SiC stress-grading coating decreases,while the non-linear coefficient increases.A larger control range can be obtained by altering the varieties of SiC powder and the number of the anti-corona coating,then the requirement of multilevel anti-corona structures can be satisfied.