The effects of insulation material and methods of fabrication on the performance of compact Helical Flux Compression Generators

Helical Flux Compression Generators, HFCGs, are powerful high current sources for pulsed power applications. Due to the single shot nature of HFCGs, electrical output reproducibility is of great importance. One factor known to contribute to unpredictable performance is mechanical inconsistencies introduced during manufacturing of the stator. In an attempt to minimize these deviations during productions, two different winding forms for stator coils, designed to ensure repeatable generator dimensions, turn and coil pitch, were investigated. The differences between the methods were quantified by comparison of measurements made of the physical parameters of the coil (i.e. radius, inductance, etc.), as well as analysis of experiments conducted with the HFCGs fired into a 3 μH load inductor. With any particular fabrication method, the stator insulation material has a distinct impact on generator operation. Quad-built Polyimide coated magnet wire as stator insulation material and Teflon Fluorinated Ethylene Propylene (FEP) as field coil insulation material were investigate to improve HFCG performance. Insulation testing was carried out by firing HFCGs into the inductive load mentioned above. Experimental data and analysis, as well as conclusions on insulation material, will be presented along with a brief discussion of the optimum fabrication method.

I. INTRODUCTION

Helical flux compression generators, HFCGs, are compact sources for high current, single use, single shot applications. Their ability to achieve high energy amplification and to drive high impedance loads makes them attractive sources for pulsed power systems (PPS). However, HFCG output consistency and repeatability is required and HFCGs are known to exhibit large statistical fluctuations in performance from shot to shot [1]. With the goal to increase HFCG consistency and reproducibility, different winding mandrels were explored.