Design of a compact pulse transformer

To improve the pulse shape and to obtain μs order pulse duration on a diode load in an inductive energy storage system, an oil-submerged compact pulse transformer with diameter of 20 cm and length of 70 cm has been designed and tested. From theoretical calculations, the parameters with primary inductance L_p = 3.4 μH, secondary inductance L_s = 90 μH, and coupling coefficient K = 0.772 are obtained. To prevent breakdown, a conic secondary design is adopted. Under the condition of 500 kV operation voltage, the maximum electric field in the transformer is 205 kV/cm (in oil). The axial voltage distribution on the secondary is linear. Experiments have been done to test the insulation, the mechanical force and the coupling coefficient. The test results are consistent with the design parameters.