Unbalanced Converter Operation

The results of a digital computer investigation of the effects of unbalanced alternating voltages on converter operation is described. The problem is approached from the standpoint of symmetrical components and an exact analysis has been carried out for an arbitrary ratio of positive and negative sequence voltages. Variation of the grid control firing angle has been considered permitting a full range of rectifier and inverter performance. Effect of the magnitude of commutating reactance is also investigated. With the analysis of the data obtained from the exact representation indicated, it is possible to obtain the sequence impedances. It should be noted that these sequence impedances are a mathematical simplification and are not made of physically realizable R, L, or C, components.