A compact design method for Tesla-type pulse transformer

Background The miniaturization of pulse power sources is the development direction of high power electromagnetic pulse generation field. With the application of the novel dielectric propylene carbonate in pulse power technology, the size of pulse power sources is reduced and the energy storage density is greatly improved. Among them, small-sized Tesla-type pulse transformers face the challenge of high step-up ratio design.

Purpose This study aims to increase the number of turns of the secondary coil inside a coaxial pulse transformer, a design method for conical stacked coils based on voltage equalization for every cone section is proposed.

Methods Each cone section is nested inside and outside, mounted coaxially, and connected head of one cone to end of another adjacent cone. The contact radius of adjacent cone sections is determined through theoretical calculations. A combination of sparse and dense winding methods is used to design the number of coil turns of the cone section, ensuring that the number of coil turns and voltage difference of each cone section are consistent. Meanwhile, the risk of breakdown between the coils at both ends of one cone section can also be reduced.

Results A triple-cone stacked secondary coil has been developed, which has increased by nearly 1.4 times of windings compared to single cone coil at the same coaxial length. It is used for pulse transformer to increase voltage and to assess the stability of the developed secondary coil in a miniaturized pulse power source. The test results show that the pulse transformer adopted with a triple-cone coil works stably after being filled with sulfur hexafluoride, with a maximum operating repetition frequency of 100Hz, and has accumulated nearly 100000 pulses without faults.

Conclusions The new design method of stacked secondary coils can design multi-cone coils based on the size of the inner and outer cylinders of the pulse transformer, achieving high secondary voltage of Tesla-type pulse transformers and improving the compactness level of pulse power sources.