An Equation-Based Dynamic Nonlinear Model of Metal-Oxide Arrester and Its SPICE Implementation

The existing models of the Metal-Oxide arresters (MOA) have difficulty covering the behavior prediction under surges with front time ranging from microseconds to nanoseconds. This brief presents an equation-based dynamic nonlinear model and its circuit implementation, which can describe the behavior of the MOA in a wide range of frequencies and amplitudes with the consideration of the piecewise nonlinearity and the dynamic nonlinearity characteristics. The model can be easily constructed based on the manufacturer's data and a multiplication factor table for the dynamic characteristic. Two types of MOA used in the power distribution systems are tested to validate the proposed model. The simulated responses of MOAs are in good agreement with the measured results when the MOAs are applied to impulses with front time ranging from 20 ns to 30 μ s. Both the errors of the peak voltage and the absorbed energy between simulated and measured results are less than 6%.