Impacts of DFIG and Type IV WTG‟ Capacity and the Location of Placement on IEEE 13 Node Radial Test Feeder Positive, Negative and Zero Sequence Reactance in Short Circuits

Abstract

With the ever increasing number and capacities of the distributed generations (DGs)penetrating the conventional radial electrical power distribution networks, there is need for a detailed assessment on the impacts the DGs have on the distribution network's sequence impedances during fault conditions. The conventional distribution networks are designed to extract power from the transmission network and distribute it to the loads. The distribution networks were not designed to have DGs directly connected into them hence their power flow is unidirectional from the main utility grid to the loads. When balanced, un-faulted and in normal operating state, the power system's voltages and currents can be evaluated and determined with utmost simplicity. When the power systems is balanced and un-faulted, the line and phase for both the voltages and the currents are of equal magnitudes and displaced by 120º from each other, however, when the power system network is unbalanced and faulted, the magnitudes of the phase voltages and currents are not equal and are displaced by angles more or less than 120º, hence evaluating and determining the network quantities can be difficult under the unbalanced and faulted operating conditions.