Optimal load shedding in distributed networks with sigmoid cost functions

The transformation of electric distribution networks towards active distribution networks leads to new possibilities in load shedding strategies, enabling more efficient load drop mechanisms in comparison to traditional networks. This paper presents an extended approach of the traditional load shedding formulation that also incorporates the cost of lost load of priority elements such as critical infrastructures, connected to the electricity grid. For this purpose, a sigmoid cost function is used. The proposed approach is formulated as a nonlinear optimization problem and solved by an interior-point method. The approach is tested using a 33 bus reference network and illustrative priority cost functions based on sigmoid functions. The results show that lost load at nodes with higher priority can be adjusted to individual demand characteristics in a more flexible way, leading to an improved overall solution in comparison to the traditional approach.