A multi-slack Optimization Model for Scheduling Energy Hubs in Smart Grids

Iman Gerami Moghaddam, Mohsen Saniei, Elahe Mashhour


This paper provides a multi-slack optimization model in order to manage the operation of an energy hub in smart grids.
This model is centralized on a multi-slack one in which the proposed slack variables are in line with actual energy providers.
Both electrical and thermal loads are considered in this model. An external grid and boilers are respectively used for slack
generation units for satisfying electrical and thermal loads. In order to reduce the penalty factors in the optimization model,
we addressed fair and suitable slack variables in the optimization model. In a real power system, energy storage devices
could effect optimal operation in short-term planning. The main role of such devices in smart grids is to reduce the operating
costs because of their state of charge (SOC) in peak, medium and base loads. Such devices could also handle load and
generation uncertainties in the real world. In this model, we implement this feature to handle the uncertainties in the random
variable generation sector of optimization algorithm. The proposed method could handle this challenge by discharging the
stored energy if the slack unit is unable to satisfy the demanded load and vice versa. In order to evaluate the effectiveness
of the proposed method, a benchmark is provided in this paper. The hourly electrical and thermal demands were extracted
from DesignBuilder® for a commercial building. The simulation results show that the presented method is both satisfactory
and consistent with expectations.


: Energy Hub;Combined heat and power; Multi-Slack Optimization Model; State of Charge

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