Background The high-voltage stability of the extraction power supply for metal ion sources directly determines the beam quality. Traditional extraction power supplies rely on large-capacity energy storage to suppress voltage droop, which leads to excessive short-circuit energy during load breakdown and subsequent erosion of the extraction electrodes.
Purpose To resolve this inherent technical conflict between high-voltage stability and low-energy protection, this study aims to develop a low-energy-storage high-voltage power supply system that minimizes breakdown energy without sacrificing voltage stability.
Methods A novel power supply topology based on series active compensation at the output terminal is proposed, featuring a decoupling design between the main circuit and the compensation circuit. Specifically, a small 0.1 μF capacitor is utilized in the main circuit to limit the breakdown energy, while five stages of 800 V floating low-voltage compensation modules are connected in series at the output. Furthermore, a voltage-threshold control strategy is employed for dynamic compensation of the load voltage under a pulse operating condition of 100 kV/200 mA/2 ms/10 Hz.
Results Simulation results demonstrate that, compared with the traditional 0.5 μF large-capacity scheme, the proposed system reduces the total energy storage of the main capacitor by 80% while maintaining a voltage droop rate of 0.6%. Additionally, a low-voltage experimental platform was developed to validate the feasibility of the topology and control strategy.
Conclusions The proposed series active compensation approach effectively resolves the contradiction between high-voltage stability and low-energy protection, significantly providing a technical reference of the extraction power supply.
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