A New Method to Detect Corona Discharge in Power Equipment

Corona discharge in insulating material commonly occurs in power equipment, which endangers the operation of power system. Early detection of corona discharge can prevent large-scale failure, protect the expensive electrical equipment and ensure the reliable operation of power system, which is of practical significance and economic value. In this work, a new composite insulating material, poly(3-hexylthiophene)/polystyrene (P3HT/PS) blend film is fabricated, which shows observable colour changes under corona discharge. Based on oxidation of P3HT, the colour change of P3HT/PS blend film becomes more obvious with the increase in applied voltage and discharge duration. Thus, P3HT/PS blend film can be used as an estimation material of corona discharge intensity with eye observation. According to the UV-Vis spectra, the absorption peak position of corona treated P3HT/PS film is blue shifted and the film absorbance is decreased with enlarged applied voltage and corona treat duration, which can be utilized as a quantitative method to characterize corona discharge. Breakdown results show slightly decreased insulating strength when insulating polymer is coated with P3HT, which prove the potential of P3HT detector in detecting corona discharge in power applications.