基于改变环流阻抗的并联解耦控制策略

目前多逆变器并联系统大多采用均值均流控制策略,均值均流控制一般采用环流有功调相及环流无功调幅控制。对于无并机电感的逆变器并联系统,通过环流功率进行调相、调幅的调节控制受逆变器电压波形控制参数影响且存在耦合关系。本文针对均流控制进行分析提出了环流阻抗概念。根据环流阻抗概念提出了环流阻抗调节器用以改变并联系统的环流阻抗。在此基础上设计了均流控制调节器并进行实验验证。实验结果表明,该均流控制策略取得了良好的均流效果。

A Decoupled Current-Sharing Strategy Based on Circulating-Impedance in Parallel Operation

The strategy, in which circulating active/reactive power is used to compensate the magnitude and phase of the output voltage reference, is employed in most of parallel multi-inverter systems at present. When the parallel system is without connection-inductors, the relationship between the circulating active/reactive power and magnitude, phase of the output voltage reference is always complex and coupled. The relationship is analyzed, then the concept of circulating impedance is proposed in the paper. Circulating-impedance controller is designed, by which the circula-ting-impedance of parallel system is controlled to be a desired value. The current-sharing strategy based on circulating-impedance is used in the experiment. The results of experiment verify that the current-sharing strategy is available and efficient.