662 / 2022-03-31 10:49:12

Study on Detection and Evaluation Method of Internal Overheating Defects in HVDC Bushing

HVDC bushing, overheating defects, electromagnetic-thermal analysis, detection method

HVDC bushing operates under high voltage and high current, so its internal overheating defects occur frequently, which affects the operation of HVDC transmission system.  This paper proposed an equivalent calculation method for internal overheating defects and set up a 3-D electromagnetic-thermal analysis model for the HVDC bushings, and the accuracy of the model was verified based on field data, the error was less than 2%.  Using this model, the distribution characteristics of heat source and the variation of surface temperature under different defects were investigated. On this basis, a method of overheating defect detection and evaluation in bushings based on surface temperature characteristic ΔT is proposed. Through field verification, this method can used to detect and locate the overheating defect in the bushings intuitively and effectively.