Abstract：One of the major threats to safe operation of the pad-mounted transformer is the failure of high voltage current-limiting fuse such as explosion melting. In view of explosive melting problem of high voltage current-limiting fuse of pad-mounted transformer for wind turbine applications, the main failure cause is analyzed. One reason is that the design and selection did not meet the requirements for reducing fuse capacity. The second reason is oil seeping at copper sheet of lead wire. The third reason is that heat accumulation for a long time causes accelerated aging of insulation. The temperature rise test of the fuse with rated current of 31.5A indicates that it is possible that the internal temperature of the high voltage current-limiting fuse is 25K higher than the external oil temperature. That is, when the external oil temperature is at or above 75℃, the temperature in the dry cylinder will reach 100℃. It is suggested that the design should be reasonably reduced capacity according to the actual installation of high voltage current-limiting fuse. Taking 1600kVA pad-mounted transformer as an example, the improvement example of design and selection is presented. The study of this paper has important reference significance for the application of high voltage current-limiting fuse.
2018, Vol. 19 
