approximation of the hydraulic constraints based on methods outlined in Menke et al. [13], By comparing the operating cost and GHG emissions of a WDS participating in a demand response scheme to one under normal operations, we compute the optimal level of demand response capacity to provide, i.e. one that minimizes the operating cost.
3. ไ. Optimization problem formulation
The optimization problem for scheduling WDS pumps for DR can be formulated as:
minimize : Pump operation cost - DR revenue. subject to : Hydraulic constraints of pumps and pipes, mass balance of the system, additional constraints from DR provision.
In the following subsections, we describe the objective function and the physical, performance and DR constraints in more detail. In this section, we use nomenclature that refers to the network model in Fig. 2 in order to explain WDS component modeling.