Cross current suppression control for parallel operation system constructed with two electric power converters under different output

Parallel connected systems constructed by connecting existing power converters in parallel have low costs and can provide large short term output. They can also be easily constructed if the allotment of the converters' output current can be controlled to different values. In this type of construction, however, it is important to reduce the cross current that flows between the converters. This paper reports two kinds of current control methods that were studied, and an examination of their cross current control performances. The performances were compared while taking into account the impedance ratio of the load and the combination reactor and allotment ratio of the output currents from two converter sets.