组合式三相逆变器输出变压器直流偏磁的抑制

摘要

本文针对数字化多环控制下组合式三相逆变器输出变压器的直流偏磁问题,详细分析了直流偏磁对逆变器的影响。结合基于ABC坐标系下重复控制加电压电流双环控制的多环控制方案,提出了一种针对多环控制的直流偏磁抑制策略。在一台额定功率为500kVA的组合式三相逆变器上进行了实验验证。实验结果证实了该策略对直流偏磁问题抑制的有效性和实用性。%The phenomenon of the magnetic bias of output transformer in three-phase full bridge inverter which is controlled by digital multi-loop control is detailed analyzed.Taking the control strategy based on combination of repetitive control and voltage and current dual-loop control in ABC reference frame for example,a scheme of restraining of magnetic bias for digital multi-loop control is proposed in this paper.The experimental results on 500 kVA prototype of three-phase full bridge inverter are presented to demonstrate the practicability and validity of the control strategy for elimination of magnetic bias.