Inventory of Load Models in Electric Power Systems via Parameter Estimation

This paper presents an approach to characterize power system loads through estimation of contributions from individual load types. In contrast to methods that fit one aggregate model to observed load behavior, this approach estimates the inventory of separate components that compose the total power consumption. Common static and dynamic models are used to represent components of the load, and parameter estimation is used to determine the amount each load contributes to the cumulative consumption. Trajectory sensitivities form the basis of the parameter estimation algorithm and give insight into which parameters are well-conditioned for estimation. Parameters of interest are contributions to total load and initial conditions for dynamic loads. Results are presented for two simulation-based studies and demonstrate the feasibility of the approach. In the first study, the composition of multiple loads connected to a bus was estimated by subjecting the bus to a step change in voltage. The second study utilized a disturbance in the WSCC nine-bus test system to facilitate estimates of the combination of loads connected at a bus in the system.