Abstract The Coil Power Supply System is one of the most critical systems in the ITER machine to provide controlled DC power to the superconductive magnets by large power AC/DC converters for the control of plasma initiation, shape and position. The AC/DC converter system leads to serious harmonic variation and risk of the low frequency oscillation, which has become a major concern. In addition, the deficiency of the voltage response for AC/DC converters could downgrade the performance of the plasma operation. This paper describes the configuration and series control strategy of the ITER AC/DC converter. Then, according to the theoretical analysis of the time-varying and broad-spectrum distributed ITER load harmonics, an improved hybrid control strategy is proposed based on the existing sequential control strategy. The hybrid control strategy can restrain harmonic current and improve voltage response performance by redistributing the voltage of each series connected unit. Finally, the representative simulation confirms the effectiveness of the control strategy.

中文翻译：

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ITER AC/DC变换器串联控制策略的改进

摘要 线圈供电系统是ITER机器中最关键的系统之一，它通过大功率AC/DC转换器为超导磁体提供受控的直流电源，以控制等离子体的起始、形状和位置。AC/DC转换器系统导致严重的谐波变化和低频振荡的风险，这已成为人们关注的主要问题。此外，AC/DC 转换器的电压响应不足可能会降低等离子体操作的性能。本文介绍了 ITER AC/DC 转换器的配置和串联控制策略。然后，根据时变广谱分布式ITER负载谐波的理论分析，在现有顺序控制策略的基础上，提出了一种改进的混合控制策略。混合控制策略可以通过重新分配每个串联单元的电压来抑制谐波电流并提高电压响应性能。最后，具有代表性的仿真证实了控制策略的有效性。