A compact pulsed-power generator based on a linear-transformer-driver scheme has been developed and tested. It consists of ten modules using a total number of 350 power metal-oxide-semiconductor field-effect transistors as switches. It is capable of generating a peak output voltage of 9 kV and a peak output current of 175 A, with a pulselength of ~ 42 ns and a repetition rate of 1 kHz. The overall system efficiency is estimated to be ~ 59%.

We have modified a solid-state Marx generator by inserting inductors into the circuit so that the inductive energy can boost the output voltage to a level several times as high as $n \times V_{0}$ , where $n$ is the number of Marx stages and $V_{0}$ is the charging voltage of each stage. Switches in the Marx generator are properly controlled allowing certain energy transfer from the capacitors to the inductors before the output begins. As a result, when all capacitors and inductors are connected in series, the voltage generated on the load is from both capacitive energy storage and inductive energy storage. In the demonstration experiment, we have used a 4-stage Marx circuit to generate an output voltage with a peak value of ~ 9 kV on a 400- $\Omega $ load, with a charging voltage of 800 V.

We have studied a water treatment by pulsed discharge plasma. To produce the plasma, pulsed high voltage is applied to an electrode. At previous studies, effects of peak, width, rise rate, and repetition rate of pulsed voltage have been confirmed. According to the studies, there is more loss at a latter part of a pulse. To reduce the loss, we investigated an effect of lowering the latter part of the pulse. In addition, an effect of periods between pulses was also investigated for optimization of pulse application timing. Those are new investigations, which were able to be carried out by various pulse forming technologies using a solid-state linear transformer driver. As the result, energy efficiency for organic compounds decomposition increased with a decrease of the latter part of pulses and with an increase of periods between pulses. A possible reason of that is the decrease of disappearance reactions of radicals owing to the decrease of those concentrations. Hence, short pulse and long periods realizes water purification of high-energy efficiency.

There have already a lot of circuit topologies for pulsed power generators using semiconductor switches. In this article, a novel circuit topology concept that can generate bipolar pulses based on linear transformer driver (LTD) topology is presented. Different from traditionally capacitive energy storage (CES) method, we utilize magnetic core as inductive energy storage (IES) medium to accumulate inductive energy before releasing pulses. The repetitive bipolar pulsed power generator is capable of operating in high repetition without reset circuit, because positive magnetization and negative magnetization can lead the magnetic core always back to initial state after every period. In this article, a three-stage laboratory prototype of bipolar IES-based LTD is designed and assembled using six existed CES-based LTD modules, which can generate ~2.4 kV bipolar peak pulses, 55 ns pulsewidth on a 150 Ω resistive load with charging voltage of 80 V. Finally, this proposed three-stage LTD is evaluated under burst mode to verified the high repetition capability of this bipolar IES-based LTD. As a result, this generator can operate at repetitive frequency of 400 kHz without reset.

A solid-state pulsed power generator has been developed. It is based on Blumlein pulse forming network (PFN) combined with saturable pulse transformer (SPT). The primary circuit is switched by a switching unit consisting of three MOS-gated thyristors connected in parallel. The SPT functions both as a transformer to increase the voltage and as a closing switch for the secondary circuit. The PFN on the secondary side is charged by the transformer and switched by the SPT so that a pulsed output is generated on a matched load. In the demonstration experiment using one module, an output with peak voltage of ~10.4 kV and pulsewidth of ~160 ns was obtained on a resistive load of 52 Ω . Furthermore, three identical modules, sharing a common primary circuit, have been connected in series to demonstrate voltage adding, where a peak output voltage of ~30 kV was obtained on a load of 156 Ω with energy efficiency of ~54 %. This pulsed power generator has been tested at repetition rate of 20 kHz in burst mode.

A new scheme of pulsed voltage adding using inductively charged Blumlein lines has been proposed and experimentally demonstrated. The circuit principle is explained based on the analogy with capacitively charged Blumlein lines. In the experiments, striplines have been used for inductive energy storage, and SiC power devices have been used as the opening switches. The experimental results have proved both the circuit behavior and the voltage adding by using multimodule stack. This circuit method is expected to become a new approach to compact and repetitive pulsed-power generation.