AbstractThree identical three-winding main step down transformers rated at 300/250/150 MVA are installed in ITER Pulsed Power Electrical Network (PPEN) to distribute power to three independent 66 kV and 22 kV busbars for feeding Coil Power Supply System (CPSS). The On-load Tap Changer (OLTC) is installed in primary side of PPEN main step down transformer to limit the voltage in required range under the control of Reactive Power Compensation and Harmonic Filter (RPC&HF) system. A comprehensive OLTC tap changer strategy has been proposed to maintain the 66 kV busbar voltage with consideration of hysteresis band to avoid strategy instability. The circuit models of OLTC tap changer transient processes have been built to analyze the terminal voltage transients quantitatively in both amplitude and phase. And the dynamic performance during OLTC tap transition has been verified to be in accordance with the analysis by simulation. And during future campaign, the most critical situation for CPSS is that the plasma operation system would give step voltage reference from minimum to maximum or vice versa to CPSS according to the operation scenarios. Hence, the converter system operation robustness has been verified by simulation on MATLAB/SIMULINK during PPEN OLTC tap changer transition in the case of this most critical situation during plasma operation.

中文翻译：

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ITER PPEN变压器有载分接开关在变流器运行过程中的策略设计与瞬态分析

摘要三台额定功率为 300/250/150 MVA 的相同三绕组主降压变压器安装在 ITER 脉冲电力网络 (PPEN) 中，将电力分配给三个独立的 66 kV 和 22 kV 母线，用于馈送线圈供电系统 (CPSS)。有载分接开关（OLTC）安装在PPEN主降压变压器的初级侧，在无功补偿和谐波滤波器（RPC&HF）系统的控制下将电压限制在所需范围内。提出了一种综合的 OLTC 分接开关策略来维持 66 kV 母线电压，同时考虑磁滞带以避免策略不稳定。建立了有载分接开关瞬态过程的电路模型，以定量分析端电压瞬态的幅值和相位。并且通过仿真验证了OLTC分接头转换过程中的动态性能与分析一致。而在未来的运动中，CPSS最关键的情况是等离子操作系统会根据操作场景给CPSS从最小到最大或反之亦然的阶跃电压参考。因此，在等离子体操作期间这种最危急情况的情况下，在 PPEN OLTC 抽头变换器转换期间，通过在 MATLAB/SIMULINK 上的仿真验证了转换器系统操作的稳健性。