Effect of Lightning Strikes Along Transmission Line With and Without Surge Arrester on Mircrogrid

The main objective for this study is to compute the voltage and current waveforms during lightning strikes. A lightning model is modeled as a double exponential form using Power Systems Computer-Aided Design (PSCAD), where it is easy to control the parameters of the model to obtain different types of lightning surges relying on IEC standard. This model is applied to the microgrid model represented by IEEE 14-buses. The effect of lightning surge on transmission line (T.L 7_9) between buses 7 and 9 is studied in this work. The work applies the surge at different positions along the transmission line and measures the voltage and current waveforms on bus 7. The results indicate that the maximum voltage and current increases at the middle of the line and disappears at the far end on bus 9. Also, the transient time from the surge initiation to steady state condition is calculated for each type of surges. The overvoltage magnitude is mitigated using surge arrester that is connected on bus 7. It is noted that the voltage magnitudes reduce 3 times, however the transient time increases. Finally, the surge arrester energy curve is computed in each case to evaluate the energy dissipated during the surge. This work concludes the importance of selecting the location of surge arrester to control the lightning surge energy.