一种可快速去磁复位变压器的新型辅助谐振变换极逆变器

A Novel Auxiliary Resonant Commutated Pole Inverter for Fast Demagnetizing and Resetting Transformer

为了提高辅助谐振变换极逆变器(auxiliary resonant commutated pole inverter,ARCPI)电路中变压器的去磁复位速度,避免剩磁通的累加使变压器饱和,提出了一种可快速去磁复位变压器的新型ARCPI。在各相辅助谐振电路中设置两个分别参与上桥臂和下桥臂之间换流过程的变压器。谐振结束之后,变压器将被施加约等于逆变器直流电源电压的反向电压,使变压器中的磁化电流快速衰减,在进入下一个脉宽调制周期前实现变压器的去磁复位。结合不同工作模式下的等效电路图,分析了工作过程,给出了软开关实现条件和辅助谐振电路损耗数学模型,讨论了谐振参数对辅助电路损耗的影响。制作了一台3 k W的单相实验样机,实验结果表明ARCPI的开关器件实现了软开关。该新型ARCPI能有效降低开关损耗和改善效率。

A novel auxiliary resonant commutated pole inverter in which auxiliary circuit could demagnetize and reset transformer rapidly was proposed to improve the demagnetizing and resetting speed of the transformer in ARCPI circuit. It avoided the saturation of the transformer that was caused by the accumulation of residual flux. Two transformers were arranged in each resonant pole to complete the commutation between the upper bridge legs and the lower bridge legs of the inverter. The transformer could obtain a reverse voltage that was about equal to the dc power voltage after the resonance, which made the magnetizing current decay rapidly. The demagnetizing and resetting of the transformer could be finished before the next commutation. The operation process was analyzed in detail on the basis of equivalent circuits at different operation mo.des. The conditions for realization of soft-switching and the mathematical model for auxiliary resonant circuit loss were presented. The influence of resonant parameters on the loss of auxiliary circuit was discussed. A 3 kW one-phase laboratory prototype had been built. The experiment results verified that the switching devices of this APCPI could realize soft-switching and the novel ARCPI presented can effectively reduce switching loss and improve efficiency.