Revealing the relationship between load aggregation and the percentage of the dynamic component with field ambient signals

Using different percentages of the dynamic component (PoDCs) for aggregated power loads has different effects on power system analysis. Meanwhile, applying fixed PoDCs in simulation systems cannot represent the time-varying and distributed characteristics of power loads. Based on the development of phasor measurement units (PMUs) and the recently proposed ambient signal based load model parameter identification method, the PoDCs identified with field ambient signals are analyzed to point out the deficiency of the fixed percentages in this paper. By taking both transmission impedance and branch paralleling into account, the relationship between load aggregation of multi-voltage levels and the PoDC of power loads is demonstrated through equivalent calculation and simulation validation to better understand the identified PoDCs. Eventually, the identification results of the field PMU measurements from China Southern Power Grid have made it clear that it is necessary to reconsider the simulation settings of the PoDC for the equivalent loads connected in 220/110 kV instead of applying fixed values at present.