This supply unit is modeled as a pressure source with a prescribed supply temperature. The delivered pressure lift of this unit is either determined by a fixed set-point or via a PI-controller that receives measurements from the network, e.g., from the weakest point in the network. The supply temperature can be set to be outside temperature controlled or constant. The main supply unit is considered as an ideal heating unit without any constraints regarding mass fow or ramp rates. The maximum heat generation is, however, limited by its nominal heat flow parameter (Q_flow_nominal).
The unit can be modelled as a simple heat and power unit using the characteristic powerCha. Electric power consumption/generation is then set according to the power values corresponding to current heat flow using table entries from the characteristic (and linearly interpolating). Electric power consumption of the pump is also considered. Since the pump is considered to be cooled by the fluid, a one to one conversion between heat added to the fluid and pumping power is considered.