Unlike the transmission networks, where each 3-phase line is represented by a single complex number – the real part of which is mostly neglected, here in a distribution network, each 3-phase line is represented at least by a 3x3 matrix. In case of 3-phase 4-wire system, the effect of neutral wire is taken into account by applying Kron’s reduction and hence a 4x4 impedance matrix is reduced to 3x3 matrix. While the Kron’s reduction eventually does not affect much the accuracy of the results, nonetheless, one loses the information which could otherwise be obtained regarding the Ground and Neutral voltages and currents. Therefore, when these quantities are of particular interest, the power flow using the 5x5 impedance matrix, called UNREDUCED impedance matrix hereafter, is the only answer.
The project work thus includes the preparation of data for the reduced and unreduced impedance matrix and development of Distribution Power Flow programs using these matrices, comparison of the results and inference drawn therefrom.