Voltage Collapse Proximity Assessment for Radial Distribution Networks

The paper deals with voltage stability assessment in radial distribution networks. The voltage collapseproximity index already utilized in literature for power transmission systems is assumed. Based on the optimalimpedance solution of a two-bus equivalent system, this index indicates how far the load nodes of the actual networkare from their voltage collapse points, allowing the weak node and its maximum load power beyond which voltagecollapse takes place to be identified. The proposed method differs from the other methods on the determination of theparameters which define the two-bus equivalent of the network, allowing to better identify the maximum loading pointbeyond which the voltage collapse takes place in the network. Simulation results show that the proposed method issignificantly more accurate than other existing methods on evaluating the critical power at a particular node (i.e. theweak node of the network) starting from any operating point, with smaller errors between actual and predicted values.