Detailed modeling of droop-controlled multi-energy systems under unbalanced operation

Considering the residential sector, greenhouse gas emissions can be effectively reduced by the widespread deployment of distributed renewable energy sources (DRESs) in low-voltage (LV) electrical networks (ENs). Through the electrification and the integration of different energy systems, the exploitation of the locally generated renewable energy can be further increased, acting also as an efficient countermeasure to the technical challenges in ENs posed by the intermittent nature of DRESs. This work deals with the modeling of multi-energy systems (MESs) consisting of unbalanced ENs and district heating networks (DHNs), formulated based on existing EN and DHN models. The developed model is enhanced by the incorporation of a thermal droop control scheme into the controllable sources of DHN, i.e., heat pumps (HPs). The validity of the proposed model is assessed via time-series simulations on a MES composed of a benchmark unbalanced LV EN and a real DHN. It is shown that the integrated droop control scheme can act as a means towards overvoltage mitigation, temperature control and reduced MES losses, improving the operational reliability and exploitation of the DRES potential. Therefore, the proposed model could be useful for system operators and decision makers for the efficient planning and operation of MESs.