Voltage multi-stability in distribution grids with power flow reversal

In future distribution grids with high penetration of distributed generators more stable solutions may appear because of active or reactive power reversal. The systems can operate at very different states, and additional control measures may be required to ensure that it remains at the appropriate point. Under typical scenarios such as subjected to disturbances or load shedding, the system may be trapped at another stable equilibrium without violating any voltage constraints. In other words, the stable equilibrium is viable. This paper aims to analyze how the distribution system converge to the second stable and viable equilibrium. The dynamic simulations are carried out using Wolfram System Modeler. The results are then analyzed and explained from various viewpoints giving better understanding of the system dynamics. In order to prevent undesired situations, new policies such as regulating reactive power compensations have been proposed. Moreover, a generic dynamic load modeling is developed to capture the essential dynamic characteristics of most of popular loads in power systems.