  In this paper we propose a semi-empirical modeling framework for aggregated
electrical load and generation using an equivalent circuit formulation. The
proposed models are based on complex rectangular voltage and current state
variables that provide a generalized form for accurately representing any
transmission and distribution components. The model is based on the split
equivalent circuit formulation that was previously shown to unify power flow,
three phase power flow, harmonic power flow, and transient analyses.
Importantly, this formulation establishes variables that are analytical and are
compatible with model fitting and machine learning approaches. The parameters
for the proposed semi-empirical load and generation models are synthesized from
measurement data and can enable real-time simulations for time varying
aggregated loads and generation.
