See Also
Base Load
Each load can be modeled as having voltage variation. The voltage variation is modeled using the Base Load Model fields on the Load Information dialog. Thus the actual real and reactive value of each load is determined using the following equation:
MW = Load MW Multiplier * (SMW + IMW * V + ZMW * V * V)
Mvar = Load Mvar Multiplier * (SMvar + IMvar * V + ZMvar * V * V)
where
MW current real power load in MW
Mvar current reactive power load in Mvar
SMW constant power MW value
Smvar constant power Mvar value
IMW constant current MW value (assuming 1.0 per unit voltage)
Imvar constant current Mvar value (assuming 1.0 per unit voltage)
ZMW constant impedance MW value (assuming 1.0 per unit voltage)
Zmvar constant impedance Mvar value (assuming 1.0 per unit voltage)
V per unit bus voltage magnitude
Load MW Multiplier = (Area MW Multiplier) * (Zone MW Multiplier)
Load Mvar Multiplier = (Area Mvar Multiplier) * (Zone Mvar Multiplier)
The Area Multipliers scale all of the loads in an area. The Zone Multipliers scale all of the loads in a zone. These are static values that do not vary over time. If a time varying schedule of loads is required, the Time Step Simulation tool should be used instead of the static multipliers.
Distributed Generation and NetMW and NetMvar
Added in Version 19 Distributed Generation MW and Mvar values may be specified with each load record. These values are only used when the Distributed Generation status is set to Closed. When Closed then this represent the distributed generation MW and Mvar represented inside this load. When this is in use, then the net MW and Mvar seen by the power flow solution algorithm will be equal to the Base Load Values minus the Distributed generation.
The Net MW Load is then NetMW= Load MW Multiplier * (SMW + IMW * V + ZMW * V * V) - DistMW
The Net Mvar Load is then NetMvar= Load Mvar Multiplier * (SMvar + IMvar * V + ZMvar * V * V) -DistMW
One thing to note in the treatment above, the Load MW Multipliers at the Area and Zone are not applied to the distributed generation value.