用于等离子体离子辐照的新型阶梯型脉冲高压电路研制

Novel Circuit Producing Pulsed High Voltage with Discrete Steps for Ion Bombardment in Plasma Immersion

为满足等离子体离子辐照和复合表面改性处理技术的发展，提出了基于Marx发生器，通过调节驱动信号延时，实现放电IGBT开关不同时导通，从而获得阶梯型脉冲高压输出的电路设计思想，并验证了其可行性。试验结果显示，该电路可输出脉冲峰值电压10kV，峰值电流30A，脉冲宽度3～30μs，脉冲频率20～500Hz，最大电压阶数10阶的高压脉冲。1个原边、10个副边结构的驱动高压隔离变压器及延时驱动电路结构紧凑，抗干扰能力强。IGBT驱动反向偏置脉冲电压能够满足IGBT快速关断和过流保护的要求。等离子体负载下电路特性测试结果表明，该电路能够适应实际的工作环境，为复合处理技术的发展提供技术支持。该电路结构通过Marx单元叠加可以拓展到更高的脉冲电压输出。

A novel circuit which is capable of producing pulsed high voltage with discrete steps based on Marx generator has been developed for ion bombardment in plasma immersion, and it is realized by means of each discharge IG- BT switching on at different time by adjusting the delay time of drive signals. A compact and robust circuit is designed, using a high-voltage isolation transformer with one primary winding and ten secondary windings for control signal and designed delay drive unit, to meet the requirements of rapidity of switch off and overcurrent protection of IGBT. A pulsed high voltage with amplitude of 10kV, peak current of 30A, pulse width of 3-30 Vs, frequency of 20-500 Hz and voltage steps of 10 are achieved. The developed circuit with several kinds of output voltage waveforms is applied to the plasma load with high reliability, and possesses the praeticability for ion bombardment or hybrid surface modification in plasma immersion mode. The higher pulse voltage may be achieved using more Marx Unit with the same control mode for wide application.