Comprehensive analysis of lightning strike activity on the power line for grid connected solar power plant

Abstract

Transmission lines of the grid-connected solar power plants are affected by lightning strikes. According to the data taken from the malfunction report of the solar power plant located in the Aegean Region of Turkey, the medium voltage switchgear was damaged due to overvoltage. The lightning impulse withstand voltage of these device is 170 kV. In order to examine the surge voltages, a model was created in the simulation program with the data received from the power plant. The surge voltages in the primary winding of the transformer by injecting lightning impulses into the transmission line were measured in the simulation. In the simulation program, three different configurations were made by changing the soil parameters, cable length, cable cross sectional area and lightning waveform. The lightning waveform is based on the International Electrotechnical Commission standard with number of 62305. It was indicated that lightning impulses in different waveforms headed for the lower grounding resistance (0.95 Ω), lower soil resistivity (11.04 Ω.m), larger cable cross sectional area (400 mm2) and longer cable (280 m). In addition, it was observed that the first positive stroke caused greater surge voltages than first negative stroke and negative subsequent stroke.