For parallel capacitor units used in AC UHV engineering

multiple capacitor units are normally in parallel connection. In case of breakdown of internal element in one unit of the capacitors

partial energy of the capacitor units in parallel with it will be injected

which will cause some influence on the fusing of the internal fuse. In order to verify the fusing characteristics of the internal fuse of multiple capacitor units in parallel connection

type BAM7.88-668-1W parallel capacitor unit is adopted in this paper and the actual operation condition is simulated by way of adding parallel samples. Artificial mechanical puncture of the prototype is used to simulate element breakdown. The test results show that in case of existence of prototype parallel capacitor units

the extent of voltage drop for fuse isolation test will be greatly reduced. In the test results

the voltage drop at the upper limit voltage in the normal isolation test is 25.71%and that at the lower limit voltage is 85.39%. In the case of two capacitor units in parallel connection

the voltage drop at the upper limit voltage in the isolation test is only 15.77% and that at the lower limit voltage is only 49.44%. The study of the fusing characteristic of the internal fuse of parallel capacitor for AC HUV engineering by test can provide reference for the use of subsequent product and is beneficial to the stable and reliable operation of capacitor.