A Network-cognizant Aggregate-frequency Reduced-order Power System Dynamical Model

摘要

This paper presents a reduced second-order power-system dynamical model that accounts for locational effects of load disturbances on system frequency dynamics over time scales corresponding to inertial and primary-frequency response. The locational aspects are retained in the proposed model by incorporating linearized power-flow balance into differential equations that describe synchronous-generator dynamics. Individual synchronous-generator speed dynamics are then combined into a single aggregate frequency state via weighting factors that can be tuned to maximize the accuracy of the reduced-order model. The proposed reduced-order model is general in the sense that its parameters are related to those of the original full-order model in analytical closed form, so that it can be constructed easily for different systems. Time-domain simulations demonstrate the accuracy of the reduced-order model with various choices of weighting factors and highlight the effect of load disturbance location on aggregate-frequency dynamics.