Study on transferred lightning overvoltage in microgrid

If the microgrid is stroke by lightning, the lightning overvoltage which transferred though distribution transformer has great influence on the safety of the microgrid. The models of microgrid and high-frequency transformers are established based on the electromagnetic transient calculation program PSCAD/EMTDC. The transferred overvoltage with different lightning strike position in microgrid is researched in this paper. The effect of surge arresters on restricting overvoltage is also analyzed. The simulation results show that surge arresters must be installed at both sides of transformer due to the high overvoltage when the transformer has no load. If the transformer is connected with cables, the overvoltage will be reduced. The longer the cable is, the lower the overvoltage is. The types of loads have a little influence on the overvoltage.