On the effects on MV/LV component expected life of slow voltage variations and harmonic distortion

The effects of electrical stress on MV/LV component expected life due to slow voltage variations and harmonic distortion are considered in a realistic scenario characterized by multimodal distributions and the presence of correlations. A simplified approach based on peak voltage mean value, recently proposed, and a new proposal are tested with reference to case studies and field measurements. The slow voltage variations and harmonic distortion contributions to the peak voltage are separated. Field measurements, performed during a whole week on a distribution network, are used to compare the entities of slow voltage variations and harmonic distortion effects and to verify the negligibility of harmonic thermal stress.