Lightning effects on distribution transformers and reliability of power distribution systems in Colombia

Failure rates of rural power systems are statistically studied based on lightning parameters and a two-state weather model (normal and  adverse). Lightning information is matched with geographical coordinates of 251,024 power transformers in a vast area in central  Colombia. An important portion of transformers present failure rates 45 times higher than normal, and very large overhead lines,  representing a high portion of the total system, present very high failure rates over 75 times higher than in normal weather conditions.