Voltage Survivability in Power Systems

The introduction of load-side control actions, to implement smart grid functions or integrate distributed generation units, has created a new source for power system dynamic events. Such events can have the capacity to adversely impact the stability in power systems. The growing interests in load-side control actions mandate the analysis and modeling of their contribution to voltage and frequency dynamics in power systems. This paper presents the analysis, development, and testing of a voltage-survivability based method for modeling the contributions of load-side control actions to power system voltage dynamics and stability. The developed method is structured using a voltage-survivability index T'v that is defined at bus in terms of the difference in reactive power injection before and after a load-side control action. The boundary values of the index T'v are derived in order to identify survivable and non-survivable load-side control actions. The voltage-survivability based method is implemented and tested for the Barbados power system. Performance tests are conducted for integrating distributed generation units, as well as implementing demand response at several load buses. Results of conducted tests demonstrate the ability of voltage-survivability based method to accurately model and quantify the impacts of load-sides activities on the bus voltages in the test power system.