低杂波电流驱动阴极高压电源系统的优化与实现

Optimization and realization of low hybrid current drive cathode high voltage power supply system

4.6 GHz低杂波电流驱动(LHCD)是EAST托卡马克装置辅助加热系统的重要组成部分。其阴极高压直流电源基于脉冲阶梯调制(PSM)技术,采用64个直流模块串联输出50 kV直流电压。单模块的调制频率设计为50 Hz,故而系统调节速度有限,面对实际运行中网侧电压波动引起的干扰时,电源无法做出更快速的响应与反馈调节,从而导致输出电压产生大幅波动,影响输出性能。为提高电源调节速度和抗干扰能力,设计了具有1 kHz调制能力的高频整流模块以替代部分原低频模块,利用高频模块的快速调节能力抑制输出电压的波动。实验结果表明,升级后的电源输出电压波动减小了50%,更好地满足速调管对于电压精度和稳定度的控制要求,保障了系统运行的可靠性。

The 4.6 GHz low hybrid current drive(LHCD) system is an important part in the EAST tokamak auxiliary heating system. Its cathode high voltage dc power supply is based on pulse stepped modulation(PSM)technology. 64 DC modules are used to output 50 kV dc voltage in series. As the modulation frequency of PSM single module is 50 Hz, the regulation speed of system is limited. In the face of the interference caused by the voltage fluctuation of the network side in the actual operation, the power supply cannot make more rapid response and feedback regulation. It leads to large fluctuation of the output voltage and affects the output performance. To improve the regulation speed and anti-interference capability of system, the high-frequency PSM module with 1 kHz modulation frequency capability was designed to replace some of the original low-frequency modules. The fluctuation of output voltage was suppressed by the rapid regulation capability of the high frequency module. The experimental results show that the output voltage fluctuation of the upgraded power supply is reduced by 50%, which better meets the control requirements of klystron for voltage accuracy and stability, and guarantees the reliability of the system operation.