This work presents a study of the effectiveness of the compensation impedance calculation methodology for the intrinsically unbalanced three-phase power distribution system (T2F). The calculation methodology in question is based on the Carson's image method to obtain impedance values that, when arranged longitudinally and transversally to the system, equalize it in order to reduce voltage unbalance levels (%DT). The comparison of the effectiveness of the calculated compensation is performed through the proposal of a computational method to obtain the impedance values that equalize the system in order to completely eliminate the unbalance between the phases. This study shows that factors such as the value of impedances implemented and their arrangement in the system directly imply the results of %DT measured in the load coupled to the circuit.Resumo: O presente trabalho apresenta um estudo da efetividade da metodologia de cálculo de impedâncias de compensação para o sistema de distribuição de energia trifásica a dois fios (T2F), intrinsecamente desbalanceado. A metodologia de cálculo em questão baseia-se no método das imagens de Carson para a obtenção dos valores de impedâncias que, quando dispostas de forma longitudinal e transversal ao sistema, equalizam o mesmo de modo a reduzir os níveis de desequilíbrio de tensão (%DT). A comparação da efetividade da compensação calculada é realizada através da proposta de um método computacional para a obtenção dos valores de impedância que equalizam o sistema de forma a eliminar completamente o desbalanço entre as fases. Este estudo mostra que fatores como o valor das impedâncias implementadas e a disposição das mesmas no sistema implicam diretamente nos resultados de %DT medidos na carga acoplada ao circuito.

This work presents an accurate method for the calculation of the compensating impedances for an uncoventional three-phase rural distribution network using two overhead wires and the ground for energy transmission. This system is referred as T2F scheme, which is an inherently unsymmetrical 3-phase system. The paper deals with the compensating method using a series impedance in the earth return path and a shunt capacitance connected between the two wires. A simulation study in MATLAB/Simulink was conducted in a medium voltage radial distribution system to verify a need of compesating impedances by analysing of unbalaced voltages and voltage drop. This study shows that the system is capable of operating within the unbalancing factor standards and voltage drops limits, as seen in the simulations results.