Sharing of nonlinear load in parallel-connected three-phase converters

In this paper, a new control method is presented which enables equal sharin g of linear and nonlinear loads in three-phase power converters connected i n parallel, without communication between the converters. The paper focuses on solving the problem that arises when two converters with harmonic compe nsation are connected in parallel. Without the new solution, they are norma lly not able to distinguish the harmonic currents that flow to the load and harmonic currents that circulate between the converters. Analysis and expe rimental results on two 90-kVA 400-Hz converters in parallel are presented. The results show that both linear and nonlinear loads can be shared equall y by the proposed concept.