Agent-based real-time voltage instability detection with Maximum Loadability Index

Developments in Distributed Generation can be both advantageous and disadvantageous for the voltage stability of a power system. The control of the system is of major importance. A smart-grid based control strategy was developed for the prevention of voltage instability called the Hierarchical Agent-Based Voltage Instability Prevention (HABVIP.) In the HABVIP system early detection of long-term voltage instability problems is important. For the HABVIP system it is required that the method meets the following design criteria: is real-time; uses local measurements only; is adaptive to topology changes. A method that is interesting for agent-based implementation is the previously developed Maximum Loadability Index (MLI). This method gives a measure of the distance of the current operating point to the point of maximum power transfer for a given transmission line or set of transmission lines. One of the problems with this method is the fact that the method assumes a fixed topology. For a typical voltage instability scenario the topology of a transmission corridor is subject to change. In this paper the original method for determining the Maximum Loadability Index is extended with a real-time estimation method for determining the equivalent line parameters. The use of this extended method is demonstrated through a simulation of a typical voltage instability scenario. It is also shown what the merit would be if the HABVIP is applied to a test power system.