The feasibility analysis of the comprehensive condition monitoring of insulation moisture defect of oil-impregnated paper bushing

Oil-impregnated paper bushing (OIP) is one of the key devices in transformer. Recently, several severely failure of OIP initiated explosion that destroyed large network transformers. A high expense of failures urged people to research the condition monitoring of the insulation defect of OIP. In this paper, the insulation defect of OIP is classified statistics based on the fault positions sourced by the CIGRE brochure and the China electric grid. Most bushing failures are caused by moisture entering the bushing through leaky gaskets or other openings. A comprehensive detection method which is combined the relative measuring method of dissipation factor with the partial discharge method for partial discharge of OIP is presented directing to the serious moisture defect of insulation moisture. It is applicable to the condition monitoring of insulation defect of bushings. It may be provide valuable reference for the condition monitor and maintain of OIP for the operation of the power system.