Closing performances of double‐gap laser‐triggered vacuum switch

The electromagnetic (EM) rail launcher G10 insulator is prone to delamination damage during launch, which affects the service life of the insulator. Through the secondary development of ABAQUS® commercial finite‐element software, an EM‐structure coupling launch dynamics model considering projectile‐barrel coupling is established. The simulation indicates that the transverse swing of the projectile changes in a sine‐like law, and the time of the upper half wave corresponds to the pulse width of the impact force pulse waveform. The stress concentration occurs on the inner surface of the insulator where the contact‐impact occurs, resulting in impact damage. The midline of the insulator inner surface bears a large compressive strain under the action of pre‐tightening force, and the insulator is compressed oscillatingly under the influence of the time‐varying load of the rail during launch. Under the condition of repeated launch, the launch package repeatedly impacts the insulator, and the alternating load of the rail is cyclically loaded on the insulator with impact damage, which will cause the compression fatigue of the insulator and the expansion of impact damage crack. They are the main reasons for the delamination failure of insulator, and the experimental analysis is carried out. This study provides a method to study the delamination failure mechanism of the insulator, and provides guidance for improving the life of the insulator.

Section: Multi-physics Field-circuit Coupling Mechanism Of Em Railgunmentioning

confidence: 99%

Delamination failure analysis of G10 insulator in electromagnetic rail launcher

Liu

Tan

et al. 2023

“…Reducing the size of the switching components facilitates the opening to improve the compactness of the switching elements. Stereo stacking is an effective method used extensively in MARX, linear transformer driver circuits [23][24][25][26]. The maximum potential difference between the series circuit boards is 24 kV, the breakdown distance of air is 0.8 cm, and its distance is set to 1.5 cm.…”

Section: Experiments Platformmentioning

confidence: 99%

A novel high‐voltage solid‐state switch based on the SiC MOSFET series and its overcurrent protection

Sun

Liao

et al. 2022

All‐solid‐state switches are one of the core components of pulsed power supply systems. However, the voltage level of a single switch is limited. By optimizing the chip structure, the voltage level of a single switch can be improved. Due to the immaturity of the production process and the positive correlation between the blocking voltage and the on‐resistance of the switch, it is difficult to improve the blocking voltage and the continuous forward current of a single switch simultaneously. The series‐connected switch is a way to increase the switch's blocking voltage without reducing the switch's continuous forward current. Magnetically coupled isolated drive and resistor‐capacitor forced voltage equalization techniques are investigated to increase the blocking voltage of the switches using multiple SiC metal‐oxide‐semiconductor field‐effect transistors (MOSFETs) in series connections. Meanwhile, a special overcurrent protection scheme is designed to improve the reliability of the series‐connected switch. Finally, a high‐voltage solid‐state switch is developed based on the SiC MOSFET series connections, whose output pulse width is adjustable from 20 to 300 μs, frequency is adjustable from 1 Hz to 3 kHz, the maximum output voltage can reach 57 kV (1 Hz), and the overcurrent protection time is about 1 μs.

“…Compared with arc discharges, active species can produce more energy efficiently through the rich non-equilibrium chemical processes in spark plasma. The unique features of spark discharge plasma have attracted increasing attention from the community of ignition and combustion [2][3][4][5], flow control [6,7], surface treatment [8][9][10], energy conversion [11][12][13], high-voltage switch design [14,15], laser ignition [16,17], and material engineering [18,19].…”

Section: Introductionmentioning

confidence: 99%

Modulating sparks in a pulse train for repetitive and energy efficient plasma generation

Yin

Zhu

2023

Spark is a widely studied plasma source for active species production; however, it experiences unstable transitions (e.g. to a thermal arc) at high frequencies or long pulse durations. In this study, the sparks generated in a pulse train were studied and modulated based on a physics‐corrected deep learning method. Our results show that a highly repeatable and stable spark plasma source can be achieved by automatically adjusting the voltage amplitude according to the discharge frequency in a high‐frequency pulse train within the time scale of the fluid response. The influences of the electron number density increasing mode and modulated driven voltage profiles on the energy efficiencies were also studied.