52 / 2017-02-27 15:59:45

Degradation Performance of Metal Oxide Arrester of EMU Under Lighting Impulses

12955,12956,12957,12958,nonlinear coefficient

In order to study the degradation characteristics of EMU under the action of continuous lightning impulse current, a lightning current impulse test platform is built, And the non-linear coefficient of the arrester is calculated. The experimental results show that there are some thresholds in the variation of parameters, such as small current and residual voltage when the lightning arrester is affected by continuous lightning current. When the number of impacts is less than the threshold, the small current characteristic and residual voltage characteristic of the arrester will not be obvious. These parameters will mutate when the number of impacts exceeds the threshold. Therefore,the low current characteristics and residual voltage characteristics of the arrester can only reflect the overall performance of the zinc oxide arrester, and can not reflect the degree of degradation. The non-linear coefficient decreases with the increase of the number of surges, and there exists a cubic polynomial function between them. Therefore, the non-linear coefficient of the EMU arrester can be used as the criterion of the degradation of the lightning arrester, which provides the theoretical basis for the life evaluation of the surge degradation.