Small sized MFCG for driving a high impedance load

Abstract

End-initiated small volume magnetic flux compression generators (MFCG) have at least one order of magnitude higher energy density (by weight or volume) than capacitive energy storage with similar discharge time characteristics. Since the prime energy is built into the MFCG in form of HE, the capacitor looses even more ground if the necessary prime energy source and the charging supply are included in the weight/volume balance. However, simple MFCGs with a single helix produce high output energy only into low inductance loads, thus producing several 100 kA of current at a voltage level of only a few 10 kV. Many pulsed power devices require less current but a considerably higher voltage level. Two approaches for achieving a higher output voltage level, both utilizing two staged MFCGs, have been reported in the open literature. The first employs a more traditional transformer coupling; the second relies on a dynamic transformer or flux-trapping scheme. Although the traditional transformer coupling has theoretically the better efficiency, we chose the latter approach for our generator design, mostly since it requires a smaller number of components. Our generator has a total length of 250 mm, a helix inner diameter of 51 mm, and is wound with Teflon insulated stranded wire of different sizes in the range from AWG 12 to AWG 22. We have presently achieved an energy gain of /spl sim/ 8 and will discuss the generator performance based on experimental current/voltage waveforms.