三相输出变压器对逆变器并联的影响

在三相逆变器并联系统中,为实现均流,需对三相输出电压进行独立调节,但这样会引起三磁柱输出变压器中磁路不平衡,进而引起励磁电流的紊乱及环流的不稳定。本文对三磁柱变压器的相间磁路耦合进行了分析和实验。发现三相电压不平衡对采用三磁柱变压器的三相逆变器并联系统的环流影响很大,这使得带三磁柱输出变压器的逆变器并联系统中,三相电压的独立调节是有害的。在此,基于三相电压的统一调节来实现均流,实验证明是切实可行的。它在实现很小环流的前提下,可使并联系统具有很强的稳定性。

Influence of Three-phase Transformers on Parallel Inverters

For the sharing of three-phase load current between parallel inverte rs,the independent regulation of each phase voltage of inverters was often used ,but it resulted in the unbalance of three-phase transformer,and then led to the disorder of the magnetic currents and the chaos of the circulating currents .This paper analyzes the coupling between three phases of the three-pole trans formers and its effect on the circulating currents between parallel inverters.An alysis and ex-periments show that the independent regulation of three-phase voltages is not suitable.The experiments based on uniform regulation of three- phase voltages show that it could achieve low circulating currents in three phas es and had great advantages both in the stability and in the response speed.