载波移相逆变器并联系统环流分析与抑制

Analysis and Restrain of Circulating Current in Carrier Phase-shifted Parallel Inverters

针对超导托卡马克核聚变实验装置(EAST)对等离子体位移快控电源输出大电流和快速响应的要求,快控电源采用基于载波移相调制技术的多组逆变器并联运行。载波移相调制技术提高了整个系统的等效开关频率,改善了输出波形质量,但也引起了并联逆变器间的环流。采用电流闭环反馈控制策略,大大增加了逆变器等效输出阻抗,有效提高了对环流的抑制能力。仿真和实验结果验证了该控制策略的可行性和有效性。

The method of multiple inverters paralleled is presented to meet the need of large current and fast control for the plasma displacement power supply in the experimental advanced superconducting Tokamak （EAST）,which based on cartier phase-shifted modulation technology.Cartier phase-shifted modulation technology increases the equiva- lent switching frequency of the system and improves the quality of the output waveform, and causes circulating current among paralleled inverters.The current close loop control strategy is adopted,which can greatly increase the equiva- lent output impedance of the inverter and can improve the ability to restrain the circulating current.Simulation and expe- rimental results indicate that the control strategy is feasible and effective.