Simulation of primary current distribution in Tesla-type pulse generators.

In a Tesla-type pulse generator, self-inductance of the primary coil is a crucial parameter to determine the final oscillating condition. However, the accurate value of this inductance might be changed due to the uneven primary current distribution caused by practical configuration of the primary side. Consequently, in order to precisely design the transformer, it is helpful to evaluate the primary inductance based on electromagnetic simulation instead of conventional approximate calculation. In this paper, a simulation model based on the finite integration technique is established to solve the uneven primary current problem. A primary coil with multiple contacting points is designed, and hexahedral mesh generation of the coil is also discussed. Hence, a series of verification tests using different primary structures are performed to support the results of simulation. Both results of the simulation model and the verification test presented that the variation of the primary inductance will affect the performance of the generator, and the number of contacting points is the main cause to determine the maximum current density of the coil.

Design and experiment studies of a 2.6-MV diverter system.

Malfunctions of the Marx pre-fire or in the event that the main switch does not close were analyzed. Principles of the diverter system for protection of those events were introduced in detail. A 2.6 MV diverter system, consisting of an oil trigger switch and a Marx-coupled trigger generator, was developed. Based on "JianGuang-I" facility, a diverter-system test stand was established. And experiments with 2.3-MV working voltages were carried out to study the performance of this diverter system. Experiment results show that the time delay of this diverter system (from the beginning of the Marx erection to the time that the diverter-switch closes) is about 320 ns and its jitter (standard deviation) is about 8.9 ns. This diverter system has been tested more than 180 shots, and no problem has been encountered yet.

Development of a Marx-coupled trigger generator with high voltages and low time delay.

Coupled by the Marx of the "JianGuang-I" facility, a high voltage, low time-delay trigger generator was developed. Working principles of this trigger generator and its key issues were described in detail. Structures of this generator were also carefully designed and optimized. Based on the "JianGuang-I" Marx generator, a test stand was established. And a series of experiment tests were carried out to the study performance of this trigger generator. Experiment results show that the output voltage of this trigger generator can be continuously adjusted from 58 kV to 384 kV. The time delay (from the beginning of the Marx-discharging pulse to the time that the output pulse of the trigger generator arises) of this trigger pulse is about 200 ns and its peak time (0%∼100%) is less than 50 ns. Experiment results also indicate that the time-delay jitter of trigger voltages decreases rapidly with the increase in the peak voltage of trigger pulses. When the trigger voltage is higher than 250 kV, the time-delay jitters (the standard deviation) are less than 7.7 ns.

A novel design of Rogowski coil for measurement of nanosecond-risetime high-level pulsed current.

In pulsed power systems, pulsed currents with risetimes from nanosecond to microsecond can be effectively measured by self-integrating Rogowski coils. Appropriate design of the structure and the integrating resistor is crucial to the high-frequency response of a coil. In this paper, several novel designs of Rogowski coil's integrating resistors were proposed and tested. Experimental results showed that the optimized coil could response square waves with fronts of ∼1.5 ns and had a sensitivity of ∼0.75 V/kA. The maximal peak current was designed as 100 kA.