Failure mode analysis of oil-free pulse capacitors

The failure mode analysis is conducted for the Oil-free (dry) Can-less pulse capacitors of 6kV working voltage. Pulse capacitor stability directly influences the dependability of the pulse power system, in which, capacitor located in. This capacitor is discharged in a low inductive circuit with sub-microsecond rise time of kA current peak pulse. Oil impregnated metal can capacitor delivers high power to the load. But use of these capacitors is limited due to high self inductance, higher weight, volume and oil leakage problems. Bi-axially oriented polypropylene (BOPP) film and aluminum foil with extended foil compact design oil-free capacitor delivers moderately high power, which comes closest to fulfilling the need. This paper describes the work done at High Voltage Laboratory in the field of oil-free pulse capacitors development and the analysis carried during development and testing of these capacitors. Which helps to improve the material, design, process, testing methods etc to develop an oil-free. Failure mode of the capacitors and some of the failed capacitors photographs are also presented.