A Dynamic Nonlinear Model for Metal-Oxide Varistor Considering the Energy Absorption Excited by Wide-Range Transients

The dynamic models of the metal-oxide varistors (MOV) have been developed successively and they show good performances in the prediction of the residual voltage. However, energy absorption, one of the most important electrical characteristics of MOV, is also worth studying, because it is a non-negligible factor to evaluate the accuracy of the model. This paper proposes a dynamic nonlinear model for MOV considering the residual voltage and the energy absorption under wide-range transients with the rise time ranging from 20 ns to 30 μs. During modeling, the characteristics of the propose model including the capacitance, the inductance and the nonlinear resistance are studied first. Then the electrical circuit is developed in ATP-EMTP. The performance of the proposed model is analyzed and compared with the IEEE model. The results indicate that the proposed model is accurate and reliable in calculating both the residual voltage and the energy, and the maximum relative errors of the residual voltage and the energy are 5.74% and 5.29%, respectively.