基于氮化镓功率器件的快前沿高压脉冲发生器

Fast-leading high-voltage pulse generator based on gallium nitride power devices

  • 摘要: 随着氮化镓功率器件在高速开关与耐压性能上的突破性发展,基于其具有导通电阻低、开关速度快、寄生参数小等优异特性,提出了一种新型隔离结构的快前沿高压脉冲功率发生器,主电路对Marx结构改进,采用共模电感隔离,结构简单,具有出色的可扩展性。对氮化镓晶体管栅极驱动回路进行优化设计,采用基于图腾柱结构的新型磁隔离驱动,利用电容储能并放电,降低磁隔离结构中绕组漏感带来的影响,提高了晶体管开关速度。实验结果,提出的脉冲发生器能产生幅值1~4 kv,脉宽200~1000 ns可调的高压脉冲,上升沿仅为5~8 ns,在等离子体和加速器系统,医疗激光,电磁兼容检测等领域具有良好的应用前景。

     

    Abstract:
    Background Traditional silicon-based Marx generators, limited by device physical limitations and leakage inductance in magnetically isolated drives, struggle to generate nanosecond-level fast pulses, particularly for applications requiring fast leading-edge pulses in plasma and other fields.
    Objective To develop a fast leading-edge high-voltage pulse generator based on gallium nitride (GaN) power devices, overcoming the bottlenecks of traditional power supplies in response speed and isolation mechanisms.
    Methods An improved modular Marx topology is proposed. The main circuit utilizes a common-mode inductor flux self-cancellation mechanism to achieve passive adaptive isolation. Simultaneously, a novel magnetically isolated synchronous drive circuit based on a totem-pole structure and capacitor compensation is designed to suppress the leading-edge delay caused by transformer leakage inductance.
    Results A 7-level solid-state experimental prototype was built. Tests show that the drive voltage rise time is shortened to 9.3 ns; at a 1 kHz repetition rate, a stable high-voltage pulse with an amplitude of 1–4 kV and a pulse width of 200–1000 ns can be output; under 1 kΩ and 400 Ω loads, the pulse rise time reaches 5–6 ns and 8.2 ns, respectively. Furthermore, the total parasitic inductance of the main circuit and the parasitic capacitance on the load side are quantitatively extracted to be approximately 2.12 μH and 16.34 pF, respectively.
    Conclusion This scheme has a simplified structure, strong scalability, effectively balances charge/discharge isolation and ultrafast synchronous drive, and possesses excellent nanosecond-level transient response performance, providing excellent hardware support for related cutting-edge applications.

     

/

返回文章
返回