Abstract
Generally a model of Metal Oxide Surge Arrester (MOSA) for numerical analysis uses a non-linear resistance. But actual Voltage-Current (V-I) characteristics of MOSA have hysterisis loop in time domain like i-Φ characteristic of a transformer and frequency dependency.
The authors have investigated relation between the actual V-I hysterisis characteristics obtained by some current waveforms and static V-I characteristics. From the voltage difference between above two characteristics, an equation was derived and a new model of MOSA was developed. This model consists of a non-linear resistance representing fundamental V-I characteristic, a linear inductance and voltage source which depends on the absorbed energy.
The calculated results by the proposed model are compared with measurement results by using the waveform of standard impulse current, steep front current and oscillated current. And the accuracy of the model has been confirmed to be satisfactory. The model is expected to be useful to investigate insulation coordination of power systems.
